==============================================================================
Claude Code session : 526f4916-08d6-4b2e-9778-0a36509a070e
Project directory   : /home/agent/TE_ting
Started             : 2026-07-17 16:07:12
Ended               : 2026-07-17 16:14:54
User prompts        : 5
Claude Code version : 2.1.211
==============================================================================
[2026-07-17 16:07:12] user:
    <command-name>/model</command-name>
                <command-message>model</command-message>
                <command-args></command-args>

[2026-07-17 16:07:12] user:
    <local-command-stdout>Set model to Opus 4.8 and saved as your default for new sessions</local-command-stdout>

[2026-07-17 16:07:19] user:
    <command-name>/effort</command-name>
                <command-message>effort</command-message>
                <command-args></command-args>

[2026-07-17 16:07:19] user:
    <local-command-stdout>Set effort level to high (saved as your default for new sessions): Comprehensive implementation with extensive testing and documentation · burns fastest — medium handles most tasks</local-command-stdout>

[2026-07-17 16:07:26] user:
    There is a Teenage Engineering Ting FX ep-2350 device attached. A guide for it can be found here: https://teenage.engineering/guides/ep-2350. It runs micropython. It's disk drive is at /media/timc/TINGDISK and its serial port is /dev/ttyACM0. I have included copies of readme files that are found with it's firmware download and on the TINGDISK drive, and a copy of its firmware UF2 file. The device is based on an RP2350 that is connected to a NAU88L21 audio CODEC chip. There are copies of the RP2350 and NAU88L21 datasheet PDFs in this directory. I want your help trying to figure out which pins on the RP2350 the NAU88L21 is connected to. We need to find the I2C pins and the I2S pins. In order to find them you can connect to the REPL of the device and run any micropython code that you want. Can you please start by writing a plan that covers what approaches you would suggest for finding the pins into ./pinmapping_plan.md

[2026-07-17 16:07:31] thinking: [not recorded in transcript]

[2026-07-17 16:07:31] agent:
    I'll start by exploring the working directory to understand what materials are available, then write the plan.

[2026-07-17 16:07:32] tool use: Bash
    command: ls -la /home/agent/TE_ting/
    description: List files in working directory

[2026-07-17 16:07:32] tool result: Bash
    total 11948
    drwxrwxr-x  3 agent agent    4096 Jul 17 16:03 .
    drwx------ 15 agent agent    4096 Jul 17 16:07 ..
    -rw-rw-r--  1 agent agent 2018007 Jul 17 13:44 DS_NAU88L21_DataSheet_EN_Rev2.8.pdf
    -rw-r--r--  1 agent agent 1544192 Dec  4  2025 ep-2350_firmware_1_0_8.uf2
    -rw-rw-r--  1 agent agent  663879 Dec  4  2025 ep-2350_firmware_1_0_8.zip
    -rw-r--r--  1 agent agent    1136 Dec  4  2025 fw_download_readme.txt
    drwxrwxr-x 16 agent agent    4096 Jul 17 14:35 micropython
    -rw-rw-r--  1 agent agent    6411 Jul 17 15:38 rom_main.py
    -rw-rw-r--  1 agent agent 7968417 Jul 17 13:52 RP-008373-DS-2-rp2350-datasheet.pdf
    -rw-rw-r--  1 agent agent    7588 Jul 17 14:47 TINGDISK_readme.txt

[2026-07-17 16:07:33] tool use: Bash
    command: ls -la /media/timc/TINGDISK/ 2>/dev/null && echo "---SERIAL---" && ls -la /dev/ttyACM0 2>/dev/null
    description: List TINGDISK contents and check serial port

[2026-07-17 16:07:41] tool result (error): Bash
    Exit code 1
    total 432
    drwxrwxr-x  3 timc removable_storage  16384 Dec 31  1969 .
    drwxr-x---+ 3 root root                4096 Jul 17 15:45 ..
    -rwxrwxr-x  1 timc removable_storage 410332 Nov  4  2025 1_.wav
    -rwxrwxr-x  1 timc removable_storage   7847 Nov  4  2025 readme.pdf
    d?????????? ? ?    ?                      ?            ? System Volume Information

[2026-07-17 16:07:46] thinking: [not recorded in transcript]

[2026-07-17 16:07:47] tool use: Bash
    command: ls -la /dev/ttyACM0; echo "---groups---"; groups; echo "---micropython dir---"; ls -la /home/agent/TE_ting/micropython/
    description: Check serial port and micropython dir

[2026-07-17 16:07:47] tool result: Bash
    crw-rw---- 1 root dialout 166, 0 Jul 17 15:45 /dev/ttyACM0
    ---groups---
    agent dialout audio
    ---micropython dir---
    total 184
    drwxrwxr-x 16 agent agent  4096 Jul 17 14:35 .
    drwxrwxr-x  4 agent agent  4096 Jul 17 16:07 ..
    -rw-rw-r--  1 agent agent 43236 Jul 17 14:35 ACKNOWLEDGEMENTS
    -rw-rw-r--  1 agent agent 13494 Jul 17 14:35 CODECONVENTIONS.md
    -rw-rw-r--  1 agent agent  2640 Jul 17 14:35 CODEOFCONDUCT.md
    -rw-rw-r--  1 agent agent   357 Jul 17 14:35 CONTRIBUTING.md
    drwxrwxr-x 19 agent agent  4096 Jul 17 14:35 docs
    drwxrwxr-x  8 agent agent  4096 Jul 17 14:35 drivers
    drwxrwxr-x 13 agent agent  4096 Jul 17 14:35 examples
    drwxrwxr-x 11 agent agent  4096 Jul 17 14:35 extmod
    drwxrwxr-x  8 agent agent  4096 Jul 17 14:35 .git
    -rw-rw-r--  1 agent agent   803 Jul 17 14:35 .gitattributes
    -rw-rw-r--  1 agent agent  2448 Jul 17 14:35 .git-blame-ignore-revs
    drwxrwxr-x  5 agent agent  4096 Jul 17 14:35 .github
    -rw-rw-r--  1 agent agent   805 Jul 17 14:35 .gitignore
    -rw-rw-r--  1 agent agent  2912 Jul 17 14:35 .gitmodules
    drwxrwxr-x 36 agent agent  4096 Jul 17 14:35 lib
    -rw-rw-r--  1 agent agent  3419 Jul 17 14:35 LICENSE
    drwxrwxr-x  2 agent agent  4096 Jul 17 14:35 logo
    drwxrwxr-x  3 agent agent  4096 Jul 17 14:35 mpy-cross
    drwxrwxr-x 21 agent agent  4096 Jul 17 14:35 ports
    -rw-rw-r--  1 agent agent  1000 Jul 17 14:35 .pre-commit-config.yaml
    drwxrwxr-x  2 agent agent 12288 Jul 17 14:35 py
    -rw-rw-r--  1 agent agent  3091 Jul 17 14:35 pyproject.toml
    -rw-rw-r--  1 agent agent 13785 Jul 17 14:35 README.md
    drwxrwxr-x  9 agent agent  4096 Jul 17 14:35 shared
    drwxrwxr-x 31 agent agent  4096 Jul 17 14:35 tests
    drwxrwxr-x  5 agent agent  4096 Jul 17 14:35 tools

[2026-07-17 16:07:48] tool use: Read
    file_path: /home/agent/TE_ting/fw_download_readme.txt

[2026-07-17 16:07:48] tool result: Read
    1	# EP-2350 release log
    2	
    3	## upgrading the firmware
    4	1. remove the lower lid.
    5	2. attach a usb-c cable from the device to your computer.
    6	3. press and hold the handle during the entire upgrade process.
    7	4. while still holding the handle, double-click the small button located above the usb port.
    8	5. a drive named "TING BOOT" will appear on your computer. this drive will contain the files INDEX.HTM and INFO_UF2.TXT.
    9	6. drag and drop the firmware file onto this drive.
    10	7. wait for the file to finish transferring.
    11	8. once transferred, the unit will automatically restart (the white led will turn on).
    12	
    13	## firmware rev 1.0.8 release notes
    14	  - pulsating noise floor fixed
    15	
    16	## firmware rev 1.0.7 release notes
    17	  - spurious click in reverb when changing preset removed
    18	
    19	## firmware rev 1.0.6 release notes
    20	  - sample loop glitch fixed
    21	  - json loading regression from 1.0.5 fixed
    22	  - some json parsing errors fixed
    23	  - factory samples are no longer loaded after sleep
    24	
    25	## firmware rev 1.0.5 release notes
    26	  - fix of upgrade mode drive name, vid/pid
    27	  - eject drive now reloads samples and settings
    28	  - lowered microphone compared to sample replay
    29

[2026-07-17 16:07:48] tool use: Read
    file_path: /home/agent/TE_ting/TINGDISK_readme.txt

[2026-07-17 16:07:48] tool result: Read
    1	# TING
    2	thank you for buying EP-2350 TING, a full instruction and warranty terms can be
    3	found on teenage engineering's website https://teenage.engineering
    4	## using TING
    5	power it by inserting 2 x AAA batteries or attaching to a USB power source.
    6	push the handle to start. you must also push the handle to enable the microphone.
    7	on batteries:
    8	* 5 min after releasing the handle the unit goes into power save mode
    9	* 20 min after releasing the handle the unit turns off
    10	* if the battery voltage is too low an LED will blink
    11	and the unit will not turn on
    12	* remove the batteries if the unit is stored
    13	on usb power:
    14	* the unit will stay powered until you pull the cable
    15	* the batteries are not used if there is usb power
    16	* the batteries are not charged
    17	WARNING: loud sound levels leads to hearing loss. TING is designed to connect
    18	to the RIDDIM or an audio mixer, not directly to headphones.
    19	signal level out is 2 VRMS and this can be very loud connecting directly to
    20	headphones, under the lid there is a round green turn to adjust the volume.
    21	the orange button selects between clean voice and 4 effect presets
    22	some of the effect parameters are modulated by the position of the handle,
    23	some are effected by if you shake the unit.
    24	[ clean, echo, echo+spring, pixie, robot ]
    25	the green button selects between 4 preset samples. if you want to
    26	you can change these to your own samples.
    27	[ siren, alarm, gunshot, monkey boy ]
    28	the white button plays the selected sample.
    29	### pushing the handle
    30	the position of the handle can change the amount of an effect.
    31	### shaking the unit
    32	shaking the unit temporarily modifies the sound of the effect,
    33	how is preset dependent.
    34	## upgrading the firmware
    35	first you will need a firmware uf2 file. if there is a new firmware this can
    36	be downloaded from teenage engineering's website.
    37	remove the lower lid and attach a usb-c cable to your computer,
    38	hold in the handle and then double click the small button above the usb port.
    39	a drive called TING BOOT should appear in your computer containing the files
    40	INDEX.HTM and INFO_UF2.TXT, drag and drop the firmware file to this drive
    41	and wait until transferred and the unit restarts. do not release the handle
    42	until the the operation is finished.
    43	## changing the samples
    44	overriding a preset sample with your own sample is done by placing files called
    45	1.wav, 2.wav, 3.wav and 4.wav on the TING DISK. only wav format is allowed and
    46	the total file size is about 1 MB. the samples can be mono or stereo, 8/16/24-bit
    47	or 32-bit floating point, with a frequency up to 96 kHz. the samples are not
    48	available until the unit is restarted, push the button over the usb-c port
    49	turn it off and push the handle to start again.
    50	## config.json
    51	a file called config.json overrides the presets and selects what samples to play.
    52	json is a human-readable data exchange format that that TING can interpret.
    53	please look at the example syntax and you will be able to write your own.
    54	some effects like delay, reverb, harmony and ssb should only be used ones per
    55	effect chain. parameters not initialized will have a default value. if your
    56	config file is so extreme that the unit will not start, hold green + white
    57	button when starting and then fix the file.
    58	### example
    59	~~
    60	{
    61	"name": "We count from zero",
    62	"samples": [
    63	{ "pos": 1, "file": "samples/whistle1.wav","playmode": "oneshot" },
    64	{ "pos": 0, "file": "live1/loop.wav","playmode": "startstop" },
    65	{ "file": "horn.wav","playmode": "hold" },
    66	{ "file": "live1/shottis.wav","playmode": "oneshot" }
    67	],
    68	"presets": [
    69	{
    70	"pos": 0,
    71	"list": [
    72	{ "effect": "HARMONY", "pitch": 2.0, "BUS": 2
    73	},
    74	{ "effect": "REVERB", "time": 0.1, "dry-level": 1.0 },
    75	{ "effect": "DELAY","time": 0.5, "dry-level": 0.0, "echo": 0.5, "BUS": 1 },
    76	{ "effect": "SAMPLE", "speed": 1.0 }
    77	],
    78	"handle": { "row": 1, "param": "time","depth": 0.6 },
    79	"shake": { "row": 2, "param": "echo", "depth": 1.0 },
    80	"lfo": { "row": 3, "param": "echo", "depth": 1.0,
    81	"mpy": 1.0, "shape": "random", "phase": 0, "speed", 4.0 },
    82	"trigger": { "row": 3 }
    83	},
    84	{
    85	"pos": 2,
    86	"list": [
    87	{ "effect": "HARMONY", "pitch": 2.0 },
    88	{ "effect": "SAMPLE", "speed": 2.0 },
    89	{ "effect": "REVERB", "time": 1.0, "spring": 0.5 },
    90	{ "effect": "DELAY", "time": 0.1, "echo": 0.5 }
    91	],
    92	"handle": { "row": 2, "param": "pitch", "depth": -0.2 },
    93	"trigger": { "row": 1 }
    94	}
    95	]
    96	}
    97	~~
    98	### effects
    99	BALANCE:
    100	balance
    101	[0.0, 1.0]
    102	DELAY:
    103	time
    104	lowpass-cutoff
    105	highpass-cutoff
    106	wet-level
    107	dry-level
    108	echo
    109	cross-feed
    110	balance[0.0, 1.2]
    111	[0.0, 1.0]
    112	[0.0, 1.0]
    113	[0.0, 1.0]
    114	[0.0, 1.0]
    115	[0.0, 1.0]
    116	[0.0, 1.0]
    117	[0.0, 1.0]
    118	DIST:
    119	amount
    120	highpass-cutoff
    121	lowpass-cutoff
    122	mix[0.0, 40.0]
    123	[0.0, 1.0]
    124	[0.0, 1.0]
    125	[0.0, 1.0]
    126	HARMONY:
    127	dry-level
    128	pitch[0.0, 1.0]
    129	[0.50, 2.0]
    130	HIGHPASS:
    131	cutoff[0.0, 1.0]
    132	LOWPASS:
    133	cutoff[0.0, 1.0]
    134	SAMPLE:
    135	speed
    136	pitch
    137	level
    138	balance[0.0, 4.0]
    139	[-24.0, 24.0]
    140	[0.0, 1.0]
    141	[0.0, 1.0]
    142	REVERB:
    143	dry-level
    144	wet-level
    145	time
    146	spring-mix
    147	highpass-cutoff[0.0, 1.0]
    148	[0.0, 1.0]
    149	[0.0, 1.0]
    150	[0.0, 1.0]
    151	[0.0, 1.0]
    152	RING:
    153	frequency
    154	mix[0.0, 20000.0]
    155	[0.0, 1.0]
    156	SSB:
    157	frequency
    158	[-20000.0, 20000.0]
    159	### LFO shapes
    160	[ sine, square, sawtooth, random ]
    161	## Licenses
    162	copyright (c) 2025 teenage engineering, all rights reserved,
    163	teenage engineering holds all rights to its registered trademarks.
    164	### PICO SDK
    165	Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
    166	1. Redistributions of source code must retain the above copyright notice,
    167	this list of conditions and the following disclaimer.
    168	2. Redistributions in binary form must reproduce the above copyright notice,
    169	this list of conditions and the following disclaimer in the documentation
    170	and/or other materials provided with the distribution.
    171	3. Neither the name of the copyright holder nor the names of its contributors
    172	may be used to endorse or promote products derived from this software
    173	without specific prior written permission.
    174	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
    175	AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
    176	WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
    177	IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY
    178	DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
    179	(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
    180	SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
    181	HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    182	LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
    183	OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    184	### MICROPYTHON
    185	Copyright (c) 2013-2025 Damien P. George
    186	The MIT License (MIT)
    187	Permission is hereby granted, free of charge, to any person obtaining a copy
    188	of this software and associated documentation files (the "Software"), to deal
    189	in the Software without restriction, including without limitation the rights
    190	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    191	copies of the Software, and to permit persons to whom the Software is
    192	furnished to do so, subject to the following conditions:
    193	The above copyright notice and this permission notice shall be included in
    194	all copies or substantial portions of the Software.
    195	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    196	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    197	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    198	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    199	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    200	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    201	THE SOFTWARE.
    202

[2026-07-17 16:07:48] tool use: Read
    file_path: /home/agent/TE_ting/rom_main.py

[2026-07-17 16:07:48] tool result: Read
    1	import os
    2	import json
    3	import ui
    4	import spl
    5	import fx
    6	
    7	sam_pos = 0
    8	fx_pos = -1
    9	sam_primed = 0
    10	fx_primed = 0
    11	ui.leds(fx_pos,sam_pos)
    12	ui.callback(0)
    13	
    14	def examine_drive(mount):
    15	    if mount == True:
    16	        # print("Mounting")
    17	        import vfs,rp2
    18	        # Try to mount the filesystem, and format the flash if it doesn't exist.
    19	        bdev = rp2.Flash()
    20	        vfs.umount("/fat")
    21	        try:
    22	            vfs.mount(vfs.VfsFat(bdev), "/fat")
    23	        except:
    24	            # print("Formatting")
    25	            vfs.VfsFat.mkfs(bdev)
    26	            vfs.mount(vfs.VfsFat(bdev), "/fat")
    27	        del vfs, bdev
    28	    # print("Done mounting")
    29	
    30	    json_loaded = False
    31	    try:
    32	        os.chdir('/fat')
    33	        try:
    34	            f = open('config.json','r')
    35	            d = json.load(f)
    36	            f.close()
    37	            json_loaded = True
    38	        except:
    39	            try:
    40	                f = open('1.wav','rb')
    41	                spl.load_wav(0,f,0)
    42	                f.close()
    43	            except:
    44	                spl.rom(0)
    45	            try:
    46	                f = open('2.wav','rb')
    47	                spl.load_wav(1,f,0)
    48	                f.close()
    49	            except:
    50	                spl.rom(1)
    51	            try:
    52	                f = open('3.wav','rb')
    53	                spl.load_wav(2,f,0)
    54	                f.close()
    55	            except:
    56	                spl.rom(2)
    57	            try:
    58	                f = open('4.wav','rb')
    59	                spl.load_wav(3,f,0)
    60	                f.close()
    61	            except:
    62	                spl.rom(3)
    63	    except:
    64	        spl.rom(0)
    65	        spl.rom(1)
    66	        spl.rom(2)
    67	        spl.rom(3)
    68	
    69	    if json_loaded == True:
    70	        # load potential samples
    71	        spl.rom(0)
    72	        spl.rom(1)
    73	        spl.rom(2)
    74	        spl.rom(3)
    75	        for i in range(4):
    76	            try:
    77	                pos = d.get('samples')[i].get('pos')
    78	                if (pos >= 4) or (pos < 0):
    79	                    pos = i
    80	            except:
    81	                pos = i
    82	
    83	            try:
    84	                g=open(d.get('samples')[i].get('file'),'rb')
    85	
    86	                try:
    87	                    pm = d.get('samples')[i].get('playmode')
    88	                except:
    89	                    pm = 'oneshot'
    90	                if pm is None:
    91	                    pm = 'oneshot'
    92	                if not spl.load_wav(pos,g,pm):
    93	                    spl.rom(pos)
    94	                g.close()
    95	            except:
    96	                pass
    97	
    98	        # parse the effect chains
    99	        try:
    100	            n = len(d.get('presets'))
    101	        except:
    102	            n = 0
    103	
    104	        for i in range(n):
    105	            try:
    106	                pos = d.get('presets')[i].get('pos')
    107	                if (pos >= 4) or (pos < 0):
    108	                    pos = i
    109	            except:
    110	                pos = i
    111	
    112	            fx.preset_mods_disable(pos)
    113	
    114	            for j in range (16):
    115	                try:
    116	                    l = d.get('presets')[i].get('list')[j]
    117	                except:
    118	                    fx.preset(pos,j,'END')
    119	                    break
    120	                try:
    121	                    effect = l.get('effect')
    122	                except:
    123	                    fx.preset(pos,j,'END')
    124	                    break
    125	
    126	                fx.preset(pos,j,effect)
    127	                for key, value in l.items():
    128	                    if key != 'effect':
    129	                        fx.preset_param(pos,j,key,float(value))
    130	
    131	            if d.get('presets')[i].get('handle'):
    132	                try:
    133	                    value = d.get('presets')[i].get('handle').get('row')
    134	                    fx.preset_handle(pos,'row',value)
    135	                    l = d.get('presets')[i].get('handle')
    136	                    for key, value in l.items():
    137	                        fx.preset_handle(pos,key,value)
    138	                except:
    139	                    fx.preset_handle(pos,'row',-1)
    140	
    141	            if d.get('presets')[i].get('shake'):
    142	                try:
    143	                    value = d.get('presets')[i].get('shake').get('row')
    144	                    fx.preset_shake(pos,'row',value)
    145	                    l = d.get('presets')[i].get('shake')
    146	                    for key, value in l.items():
    147	                        fx.preset_shake(pos,key,value)
    148	                except:
    149	                    fx.preset_shake(pos,'row',-1)
    150	
    151	            if d.get('presets')[i].get('lfo'):
    152	                try:
    153	                    value = d.get('presets')[i].get('lfo').get('row')
    154	                    fx.preset_lfo(pos,'row',value)
    155	                    l = d.get('presets')[i].get('lfo')
    156	                    for key, value in l.items():
    157	                        fx.preset_lfo(pos,key,value)
    158	                except:
    159	                    fx.preset_lfo(pos,'row',-1)
    160	
    161	            try:
    162	                fx.preset_trigger_row(pos,d.get('presets')[i].get('trigger').get('row'))
    163	            except:
    164	                pass
    165	
    166	examine_drive(False)
    167	
    168	fx.load_preset(fx_pos)
    169	
    170	def python_callback(message):
    171	    #print(f"callback {message:08x}")
    172	    global sam_pos
    173	    global fx_pos
    174	    global sam_primed
    175	    global fx_primed
    176	    mess_type = message >> 16
    177	    mess_val = message & 0xFFFF
    178	    #type = mess_type & 0xF0
    179	    #adc = mess_type & 0x0F
    180	    #print(f"adc {type} {adc} {mess_val}")
    181	
    182	    if mess_type == 1:
    183	
    184	        if mess_val == 0:
    185	            spl.trigger(-1,sam_pos,True)
    186	
    187	        if mess_val == 1:
    188	            if ui.sw(4) == 0:
    189	                sam_primed = 10
    190	
    191	        if mess_val == 2:
    192	            if ui.sw(4) == 0:
    193	                fx_primed = 10
    194	
    195	    if mess_type == 2:
    196	
    197	        if mess_val == 0:
    198	            spl.trigger(-1,sam_pos,False)
    199	
    200	        if mess_val == 1:
    201	            sam_primed = 0
    202	
    203	        if mess_val == 2:
    204	            fx_primed = 0
    205	
    206	    if mess_type == 3:
    207	        if fx_primed > 0:
    208	            fx_primed = fx_primed - 1
    209	            if fx_primed == 0:
    210	                fx_pos = fx_pos + 1
    211	                if(fx_pos >= 4):
    212	                    fx_pos = -1
    213	                fx.load_preset(fx_pos)
    214	                ui.leds(fx_pos,sam_pos)
    215	
    216	        if sam_primed > 0:
    217	            sam_primed = sam_primed - 1
    218	            if sam_primed == 0:
    219	                sam_pos = sam_pos + 1
    220	                if sam_pos >= 4:
    221	                    sam_pos = 0
    222	                ui.leds(fx_pos,sam_pos)
    223	
    224	    if mess_type == 4:
    225	            if mess_val == 1:
    226	                # print("ejected")
    227	                examine_drive(mount = True)
    228	                fx.load_preset(fx_pos)
    229	
    230	    if mess_type & 0xF0 == 0x10:
    231	        adc = mess_type & 0x0F
    232	        # print(f"adc {adc} {mess_val}")
    233	
    234	
    235	ui.callback(python_callback)
    236

[2026-07-17 16:07:55] thinking: [not recorded in transcript]

[2026-07-17 16:07:56] agent:
    This is a rich environment. Let me dig into the micropython checkout — a TE fork may contain board definitions that reveal the pins directly.

[2026-07-17 16:07:58] tool use: Bash
    command: cd /home/agent/TE_ting/micropython && echo "=== git remotes ===" && git remote -v 2>/dev/null; echo "=== branch/last commit ===" && git log --oneline -5 2>/dev/null; echo "=== recent tags/describe ===" && git describe --tags 2>/dev/null; echo "=== board dirs mentioning ting/te/ep ===" && ls ports/rp2/boards/ 2>/dev/null | grep -iE "ting|te_|ep|teenage" 
    description: Inspect micropython git and board dirs

[2026-07-17 16:08:00] tool use: Bash
    command: cd /home/agent/TE_ting/micropython && echo "=== search for NAU / I2S / codec references ===" && grep -rilE "nau88|nau8821|codec" --include=*.c --include=*.h --include=*.py --include=*.cmake --include=*.mk . 2>/dev/null | head -40
    description: Search for codec references in checkout

[2026-07-17 16:08:07] tool result: Bash
    === git remotes ===
    origin	https://github.com/micropython/micropython.git (fetch)
    origin	https://github.com/micropython/micropython.git (push)
    === branch/last commit ===
    772df1ae5 rp2: Build with -fno-math-errno to use the hardware sqrt instruction.
    ca209fd4e rp2/clocks_extra: Sync clock init with pico-sdk 2.3.0.
    ba4415d97 rp2: Reserve the ROMFS partition in the linker script.
    f6c8c156d rp2: Migrate to pico-sdk 2.3.0 include-based linker scripts.
    111d2e970 lib/pico-sdk: Update pico-sdk to 2.3.0.
    === recent tags/describe ===
    v1.29.0-preview-590-g772df1ae5
    === board dirs mentioning ting/te/ep ===
    deploy.md

[2026-07-17 16:08:09] tool result: Bash
    === search for NAU / I2S / codec references ===
    tools/autobuild/build-downloads.py
    tools/verifygitlog.py
    tests/cpydiff/types_bytes_decode_encoding.py
    ports/mimxrt/boards/PHYBOARD_RT1170/mpconfigboard.h
    ports/stm32/usbhost/Class/MTP/Inc/usbh_mtp_ptp.h
    ports/stm32/usbhost/Class/MSC/Src/usbh_msc_bot.c
    ports/cc3200/mods/pybi2c.c

[2026-07-17 16:08:47] thinking: [not recorded in transcript]

[2026-07-17 16:08:49] agent:
    This micropython checkout is stock upstream (origin = micropython/micropython, no TE/NAU customizations), so the codec init lives in the compiled UF2's custom modules (`ui`/`spl`/`fx`), not in source. That shapes the plan. Let me check available tooling and grab a couple of concrete register facts before writing.

[2026-07-17 16:08:51] tool use: Bash
    command: echo "=== serial tools ==="; which mpremote ampy rshell picocom minicom python3 2>/dev/null; echo "=== python modules ==="; python3 -c "import serial; print('pyserial', serial.__version__)" 2>&1; python3 -c "import mpremote; print('mpremote ok')" 2>&1; echo "=== pdftotext ==="; which pdftotext 2>/dev/null || echo "no pdftotext"
    description: Check serial tools and pdf tools availability

[2026-07-17 16:08:56] tool result: Bash
    === serial tools ===
    /usr/bin/python3
    === python modules ===
    pyserial 3.5
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
        import mpremote; print('mpremote ok')
        ^^^^^^^^^^^^^^^
    ModuleNotFoundError: No module named 'mpremote'
    === pdftotext ===
    /usr/bin/pdftotext

[2026-07-17 16:09:03] thinking: [not recorded in transcript]

[2026-07-17 16:09:03] agent:
    pyserial and pdftotext are available. Let me pull the RP2350 register base addresses and FUNCSEL encoding from the datasheet so the plan is concrete.

[2026-07-17 16:09:09] tool use: Bash
    command: cd /home/agent/TE_ting && pdftotext -f 1 -l 40 RP-008373-DS-2-rp2350-datasheet.pdf - 2>/dev/null | grep -inE "IO_BANK0_BASE|0x40028000|PADS_BANK0_BASE|PIO0_BASE|PIO1_BASE|I2C0_BASE|I2C1_BASE" | head -30; echo "=== try wider search ==="; pdftotext RP-008373-DS-2-rp2350-datasheet.pdf - 2>/dev/null > /tmp/claude-1001/-home-agent-TE-ting/526f4916-08d6-4b2e-9778-0a36509a070e/scratchpad/rp2350.txt; grep -inE "IO_BANK0_BASE|PADS_BANK0_BASE|PIO0_BASE|PIO1_BASE|0x40028000|0x40038000" /tmp/claude-1001/-home-agent-TE-ting/526f4916-08d6-4b2e-9778-0a36509a070e/scratchpad/rp2350.txt | head -20
    description: Extract RP2350 register bases from datasheet

[2026-07-17 16:09:19] tool result: Bash
    3668:IO_BANK0_BASE
    3670:0x40028000
    3676:PADS_BANK0_BASE
    3720:I2C0_BASE
    3724:I2C1_BASE
    3887:PIO0_BASE
    3891:PIO1_BASE
    === try wider search ===
    3668:IO_BANK0_BASE
    3670:0x40028000
    3676:PADS_BANK0_BASE
    3678:0x40038000
    3887:PIO0_BASE
    3891:PIO1_BASE
    72524:The User Bank IO registers start at a base address of 0x40028000 (defined as IO_BANK0_BASE in SDK).
    108674:The User Bank Pad Control registers start at a base address of 0x40038000 (defined as PADS_BANK0_BASE in SDK).
    129226:The PIO0 and PIO1 registers start at base addresses of 0x50200000 and 0x50300000 respectively (defined as PIO0_BASE
    129227:and PIO1_BASE in SDK).

[2026-07-17 16:09:26] thinking: [not recorded in transcript]

[2026-07-17 16:09:29] tool use: Bash
    command: cd /tmp/claude-1001/-home-agent-TE-ting/526f4916-08d6-4b2e-9778-0a36509a070e/scratchpad; echo "=== I2C bases ==="; sed -n '3718,3726p' rp2350.txt; echo "=== GPIO FUNCSEL table (search) ==="; grep -inE "F1|F2|F3|SPI0 RX|I2C0 SDA|PIO0" rp2350.txt | grep -iE "i2c0 sda|pio0|funcsel" | head; echo "=== find funcsel encoding line ==="; grep -inE "FUNCSEL" rp2350.txt | head -20
    description: Get I2C bases and FUNCSEL table

[2026-07-17 16:09:30] tool result: Bash
    === I2C bases ===
    0x40088000
    
    I2C0_BASE
    
    0x40090000
    
    I2C1_BASE
    
    0x40098000
    === GPIO FUNCSEL table (search) ===
    875:PIO0 PIO1 PIO2
    1008:GPIO0
    1152:GPIO0
    1431:peripheral connections appear in multiple places to allow some system level flexibility. SIO, PIO0, PIO1 and PIO2 can
    1477:I2C0 SDA
    1483:PIO0
    1505:PIO0
    1527:PIO0
    1551:PIO0
    1569:I2C0 SDA
    === find funcsel encoding line ===
    11422:JTAG_FUNCSEL: Multiplexes the JTAG ports onto GPIO0-3
    68672:To allocate a function to a GPIO, write to the FUNCSEL field in the CTRL register corresponding to the pin. For a list of GPIOs
    72204:invalid_params_if(HARDWARE_GPIO, ((uint32_t)fn << IO_BANK0_GPIO0_CTRL_FUNCSEL_LSB) &
    72205:~IO_BANK0_GPIO0_CTRL_FUNCSEL_BITS);
    72237:io_bank0_hw->io[gpio].ctrl = fn << IO_BANK0_GPIO0_CTRL_FUNCSEL_LSB;
    73553:funcsel
    73555:by funcsel
    73563:0x0 → NORMAL: drive output from peripheral signal selected by funcsel
    73565:funcsel
    73593:FUNCSEL: 0-31 → selects pin function according to the gpio table
    73782:funcsel
    73784:by funcsel
    73792:0x0 → NORMAL: drive output from peripheral signal selected by funcsel
    73794:funcsel
    73808:FUNCSEL: 0-31 → selects pin function according to the gpio table
    74013:funcsel
    74015:by funcsel
    74023:0x0 → NORMAL: drive output from peripheral signal selected by funcsel
    74025:funcsel
    74039:FUNCSEL: 0-31 → selects pin function according to the gpio table
    Shell cwd was reset to /home/agent/TE_ting

[2026-07-17 16:09:37] thinking: [not recorded in transcript]

[2026-07-17 16:09:38] tool use: Bash
    command: cd /tmp/claude-1001/-home-agent-TE-ting/526f4916-08d6-4b2e-9778-0a36509a070e/scratchpad; echo "=== function table header region ==="; sed -n '1431,1620p' rp2350.txt
    description: Extract GPIO function select table region

[2026-07-17 16:09:38] tool result: Bash
    === function table header region ===
    peripheral connections appear in multiple places to allow some system level flexibility. SIO, PIO0, PIO1 and PIO2 can
    connect to all GPIO pins and are controlled by software (or software controlled state machines) so can be used to
    implement many functions.
    
    1.2. Pinout reference
    
    17
    
    
    18
    Purpose Input/Output
    (GPIO) Bank 0
    
    RP2350 Datasheet
    
    Functions
    
    GPIO
    
    F0
    
    F1
    
    F2
    
    F3
    
    F4
    
    F5
    
    F6
    
    F7
    
    F8
    
    F9
    
    F10
    
    0
    
    SPI0 RX
    
    UART0 TX
    
    I2C0 SDA
    
    PWM0 A
    
    SIO
    
    PIO0
    
    PIO1
    
    PIO2
    
    QMI CS1n
    
    USB OVCUR DET
    
    1
    
    SPI0 CSn
    
    UART0 RX
    
    I2C0 SCL
    
    PWM0 B
    
    SIO
    
    PIO0
    
    PIO1
    
    PIO2
    
    TRACECLK
    
    USB VBUS DET
    
    2
    
    SPI0 SCK
    
    UART0 CTS
    
    I2C1 SDA
    
    PWM1 A
    
    SIO
    
    PIO0
    
    PIO1
    
    PIO2
    
    TRACEDATA0
    
    USB VBUS EN
    
    UART0 TX
    
    3
    
    SPI0 TX
    
    UART0 RTS
    
    I2C1 SCL
    
    PWM1 B
    
    SIO
    
    PIO0
    
    PIO1
    
    PIO2
    
    TRACEDATA1
    
    USB OVCUR DET
    
    UART0 RX
    
    4
    
    SPI0 RX
    
    UART1 TX
    
    I2C0 SDA
    
    PWM2 A
    
    SIO
    
    PIO0
    
    PIO1
    
    PIO2
    
    TRACEDATA2
    
    USB VBUS DET
    
    5
    
    SPI0 CSn
    
    UART1 RX
    
    I2C0 SCL
    
    PWM2 B
    
    SIO
    
    PIO0
    
    PIO1
    
    PIO2
    
    TRACEDATA3
    
    USB VBUS EN
    
    6
    
    SPI0 SCK
    
    UART1 CTS
    
    I2C1 SDA
    
    PWM3 A
    
    SIO
    
    PIO0
    Shell cwd was reset to /home/agent/TE_ting

[2026-07-17 16:09:54] thinking: [not recorded in transcript]

[2026-07-17 16:09:55] agent:
    I now have the concrete register facts. Let me grab the NAU88L21 I2C address from its datasheet to make the confirmation step precise.

[2026-07-17 16:09:57] tool use: Bash
    command: pdftotext DS_NAU88L21_DataSheet_EN_Rev2.8.pdf - 2>/dev/null > /tmp/claude-1001/-home-agent-TE-ting/526f4916-08d6-4b2e-9778-0a36509a070e/scratchpad/nau.txt; grep -inE "slave address|device address|i2c address|0x1a|0x1b|CSB|7-bit" /tmp/claude-1001/-home-agent-TE-ting/526f4916-08d6-4b2e-9778-0a36509a070e/scratchpad/nau.txt | head -20
    description: Find NAU88L21 I2C address

[2026-07-17 16:10:04] tool result: Bash
    455:GPIO1/CSB
    600:GPIO1/CSB
    604:General Purpose IO/CSB
    2735:(1) Set register 0x1A &= 0xFF00 (Set 0x1A[7:0] = 8’b00000000)
    2736:(2) Externally pull GPIO1/CSB pin = LOW (0V) , I2C device address = 0x1B; Or externally pull GPIO1/CSB pin =
    2737:HIGH (3.3V) , I2C device address = 0x54
    2747:Following a START condition, the master must output a device address byte. This consists of a 7-bit device address,
    2748:and the LSB of the device address byte is the R/W (Read/Write) control bit. When R/W=1, this indicates the master is
    2750:device. If the device address matches the address of the slave device, the slave will output an ACK during the period
    2801:a START condition, followed by a valid device address byte with R/W=0, a valid control address byte, data byte(s), and
    2803:The Device Address of the NAU88L21 is either 0x1B (CSB=0) or 0x54 (CSB=1). If the Device Address matches this
    2806:Figure 21: Slave Address Byte, Control Address Byte, and Data Byte
    2841:Device Address = 1Bh
    2911:The bus master initiates the operation issuing the following sequence: a START condition, device address byte with
    2914:If the device address matches this value, the NAU88L21 will respond with the expected ACK signaling as it accepts the
    2916:second instantiation of the same device address, but now with R/W=1.
    2917:After again recognizing its device address, the NAU88L21 transmits an ACK, followed by a two byte value containing
    2943:Device Address = 1Bh
    3001:2ND Device Address = 1Bh
    5813:1 = Inverted logic of the CSB/GPIO1 function output

[2026-07-17 16:10:10] thinking: [not recorded in transcript]

[2026-07-17 16:10:10] agent:
    I have everything I need. Let me write the plan.

[2026-07-17 16:11:27] tool use: Write
    file_path: /home/agent/TE_ting/pinmapping_plan.md
    content:
        # Plan: Finding the RP2350 ↔ NAU88L21 pin connections (I²C + I²S)
        
        Goal: determine which RP2350 GPIOs the NAU88L21 audio CODEC is wired to on the
        EP-2350 "Ting". We need the **I²C control bus** (SDA/SCL) and the **I²S audio
        bus** (BCLK, LRCLK/WS, DAC data-out `DOUT`, ADC data-in `DIN`, and possibly
        MCLK).
        
        ---
        
        ## 1. What we already know (from the material in this directory)
        
        - **MCU:** RP2350 (dual-core, MicroPython firmware). Reg base addresses below are
          confirmed from `RP-008373-DS-2-rp2350-datasheet.pdf`.
        - **CODEC:** Nuvoton **NAU88L21**. From `DS_NAU88L21_DataSheet_EN_Rev2.8.pdf`:
          - 7-bit **I²C device address = `0x1B`** when `CSB`=0, or **`0x54`** when `CSB`=1.
            (`GPIO1/CSB` pin selects it.) This is the signature we scan for.
          - Audio interface is standard **I²S / left-justified / PCM**, so on the RP2350
            side it is almost certainly implemented in **PIO** (RP2 has no hardware I²S).
        - **Firmware structure:** `rom_main.py` imports custom C modules baked into the
          UF2: `ui`, `spl`, `fx`. The CODEC bring-up (I²C register writes + I²S/PIO
          start) happens **inside these compiled modules**, *not* in Python.
        - **The `micropython/` checkout is stock upstream** (`origin =
          micropython/micropython`, tag ~`v1.29.0-preview`, **no** TE board dir, **no**
          `nau88`/`codec` references). So it is only the *base* MicroPython TE forked
          from — it will **not** contain the pin map. It is still useful as a reference
          for RP2 register layout and for building `mpy-cross`/`mpremote` if needed.
        - **Key consequence:** because the running firmware has *already configured* the
          CODEC before it drops us at the REPL, the pins are **already muxed to their
          final functions**. We can therefore read the mux/peripheral config live and
          simply *observe* the answer, rather than having to guess-and-test. This makes
          passive introspection (Approach A/B) the primary strategy.
        
        ---
        
        ## 2. Connection / tooling setup (prerequisite for all live approaches)
        
        - Serial REPL on `/dev/ttyACM0`. `mpremote` is **not** installed, but:
          - `pyserial 3.5` **is** installed → we can drive the raw REPL directly, or
          - build/run `micropython/tools/mpremote/` from the checkout.
        - Recommended: a small **pyserial helper** that enters raw-paste / raw REPL mode
          (Ctrl-A), sends a code blob, and reads back the result. This avoids the
          line-editor and is scriptable/repeatable.
        - The firmware auto-runs `rom_main.py` and then services audio via a C callback,
          so the **REPL should remain interactive** while audio runs. If it doesn't,
          Ctrl-C to interrupt, or use raw REPL. We must be careful **not** to `import`/
          re-init in a way that tears down the running CODEC config we want to observe
          (see Safety, §7).
        - First action: confirm liveness — read the chip ID / `sys.implementation`,
          `os.uname()`, and `import machine` succeeds.
        
        ---
        
        ## 3. Approach A — Passive mux introspection (PRIMARY, non-invasive)
        
        Read the RP2350 IO mux registers that the firmware has *already* programmed, and
        decode which pins carry which peripheral. Purely read-only.
        
        ### A1. Dump every GPIO's `FUNCSEL` from IO_BANK0
        
        - `IO_BANK0_BASE = 0x40028000`. Per GPIO *n*: `GPIOn_STATUS @ base + 8*n`,
          `GPIOn_CTRL @ base + 8*n + 4`. `FUNCSEL = CTRL[4:0]`.
        - Read `CTRL` for GPIO 0..47 with `machine.mem32[]`.
        - Decode `FUNCSEL` using the RP2350 GPIO function table (confirmed from
          datasheet §1.2 pinout):
        
          | FUNCSEL | Function family |
          |--------:|-----------------|
          | 0 (F0)  | SPI |
          | 1 (F1)  | UART |
          | **2 (F2)** | **I²C**  ← find SDA/SCL here |
          | 3 (F3)  | PWM |
          | 4 (F4)  | SIO (software GPIO) |
          | **5 (F5)** | **PIO0** ← I²S candidate |
          | **6 (F6)** | **PIO1** ← I²S candidate |
          | **7 (F7)** | **PIO2** ← I²S candidate |
          | 8–11    | clocks / trace / QMI / USB debug |
          | 31      | NULL (unconnected) |
        
        - **I²C pins fall straight out:** any pin with `FUNCSEL==2` is an I²C pin. The
          GPIO number tells us the instance and role via the datasheet's fixed pattern
          (even pin in a pair = SDA, odd = SCL; the pair index alternates I2C0/I2C1).
          Expect exactly two such pins → that's our SDA/SCL.
        - **I²S candidate pins:** pins with `FUNCSEL==5/6/7` are driven by a PIO block —
          these are our I²S candidates (plus MCLK, which may be a PIO pin or a `clk_gpout`
          on FUNCSEL 8). Narrow them down in Approach C.
        
        ### A2. Corroborate with PADS_BANK0
        
        - `PADS_BANK0_BASE = 0x40038000`. Check input-enable / output-disable / pull
          config per pin. I²C pins are typically input-enabled with pulls (often external
          on this board); I²S clock/data pins show output-enabled drivers. Helps
          distinguish `DOUT`(output) from `DIN`(input) and clocks(output) among the PIO
          pins.
        
        **Deliverable of Approach A:** a full table `GPIO → function`, from which the two
        I²C pins are essentially *proven*, and the I²S pin set is *narrowed to a handful*.
        
        ---
        
        ## 4. Approach B — Active I²C confirmation (targeted, low-risk)
        
        Confirm the I²C pins found in A1 actually talk to the NAU88L21.
        
        - **Preferred (non-disruptive):** if the firmware exposes a way to read a CODEC
          register, use it. Otherwise construct a `machine.I2C` (hardware) or
          `machine.SoftI2C` on the **exact pins found in A1** and run `.scan()`.
          - **Success signature:** the scan returns **`0x1B`** (or `0x54`). That both
            confirms the pins *and* tells us the `CSB` strap state.
          - Optionally read a known register (e.g. device/chip-ID register per the
            NAU88L21 map) to be fully certain it's the CODEC and not another I²C device.
        - If more than one I²C bus/pin-pair appeared in A1, scan each; the one ACKing
          `0x1B`/`0x54` is the CODEC bus.
        - **Risk control:** only instantiate I²C on pins A1 already showed as
          `FUNCSEL==2`. Re-driving the *correct* pins is safe; the concern is only
          transient contention if the firmware polls the CODEC concurrently — see §7.
        
        ---
        
        ## 5. Approach C — Pin down the I²S signals via PIO registers
        
        The A1 dump gives the *set* of PIO-driven pins; this step assigns each to a
        specific I²S signal (BCLK / LRCLK / DOUT / DIN / MCLK) — again read-only.
        
        - PIO bases: `PIO0 = 0x50200000`, `PIO1 = 0x50300000`, `PIO2 = 0x50400000`.
        - For each state machine (SM0..3) of each PIO, read:
          - `SMx_PINCTRL` → `OUT_BASE/OUT_COUNT`, `SET_BASE/SET_COUNT`,
            `SIDESET_BASE/SIDESET_COUNT`, `IN_BASE`. I²S typically uses **side-set for
            the two clocks** (BCLK + LRCLK/WS on consecutive pins) and OUT/IN for the
            data pins.
          - `CTRL` (which SMs are enabled) and `SMx_CLKDIV` (the divider — sanity-check it
            matches an audio bit-clock, e.g. for 48 kHz × frame size).
          - `SMx_EXECCTRL` (`JMP_PIN` etc.), `FSTAT`/`FDEBUG` to see which FIFOs are live.
        - Map: enabled SM whose `SIDESET_BASE`+count covers 2 pins ⇒ **BCLK, LRCLK**
          (consecutive GPIOs). The `OUT_BASE` data pin ⇒ **DOUT** (playback, RP2350→CODEC);
          an SM with active `IN`/RX FIFO ⇒ **DIN** (mic capture, CODEC→RP2350).
        - Cross-check output/input direction against the PADS/`GPIO_OE` state from A2.
        - **MCLK:** if the CODEC needs a master clock, look for a pin on `clk_gpout`
          (FUNCSEL 8) via `CLOCKS` GPOUT config, or an extra PIO pin.
        
        **Deliverable of Approach C:** each I²S candidate pin labeled BCLK / LRCLK /
        DOUT / DIN (/ MCLK), with direction confirmed.
        
        ---
        
        ## 6. Approach D — Static firmware analysis (corroboration / fallback)
        
        Independent confirmation that doesn't rely on the live device, and a fallback if
        the REPL is uncooperative.
        
        - Convert `ep-2350_firmware_1_0_8.uf2` → raw `.bin` (uf2 → bin: strip 512-byte
          block headers; each block carries its target load address — use `picotool` if
          available, or a tiny Python UF2 parser; the checkout has UF2 tooling).
        - Search the image for the pin numbers/config we derived live, to confirm:
          - Look for GPIO-init constant patterns and I²C/PIO setup. On RP2 these often
            appear as writes of `FUNCSEL` values or SDK `gpio_set_function(pin, fn)`
            call sites, and PIO program loads.
          - Disassemble around them (`arm-none-eabi-objdump`/`Ghidra`/`radare2` for
            Cortex-M33 / ARMv8-M) to read the literal pin numbers passed to
            `i2c_init`, `pio_gpio_init`, `sm_config_set_*_pins`, etc.
          - Grep the image for the NAU88L21 **register-init byte sequences** to confirm
            which I²C address prefix is used.
        - Use this only to *corroborate* the live findings (and to recover MCLK/reset/IRQ
          pins that may not be obvious live). Live introspection (A–C) is authoritative
          because it reflects the actual running config.
        
        ---
        
        ## 7. Safety considerations
        
        - **Non-destructive first.** Approaches A and C are pure `mem32` reads — zero risk.
          Do them before anything active.
        - Do **not** blindly `machine.Pin(n, OUT)` toggle pins to "probe" — that can
          fight the running CODEC/PIO drivers and, worst case, cause contention on a pin
          wired to a CODEC output. Rely on reading the mux instead.
        - For Approach B, only bind I²C to pins A1 proved are `FUNCSEL==2`; keep bus
          speed standard (100–400 kHz). Accept a possible transient NACK if the firmware
          accesses the CODEC at the same instant — retry rather than escalate.
        - Avoid re-flashing / entering BOOTSEL. Everything here is observation over the
          existing REPL; the UF2 on disk is our recovery image if needed.
        - Keep each REPL snippet small and idempotent; capture raw output to files under
          the scratchpad for the record.
        
        ---
        
        ## 8. Execution order (decision tree)
        
        1. **Setup (§2):** establish scriptable raw-REPL over pyserial; confirm `machine`
           works. *(gate: REPL usable)*
        2. **A1 + A2 (§3):** dump all GPIO `FUNCSEL` + pad config → table.
           → **I²C pins identified**, I²S candidates narrowed. *(this alone likely answers
           the I²C question)*
        3. **B (§4):** `I2C.scan()` on the identified pins → expect `0x1B`/`0x54`.
           → **I²C pins confirmed + CSB strap known.**
        4. **C (§5):** read PIO SM `PINCTRL`/`CTRL`/`CLKDIV` → label BCLK/LRCLK/DOUT/DIN
           (+MCLK). → **I²S pins confirmed.**
        5. **D (§6):** disassemble UF2 to corroborate and recover any aux pins
           (MCLK/reset/IRQ). *(fallback if steps 2–4 blocked, else confirmation)*
        6. Produce final **pin map table**: `signal → GPIO`, with the evidence source for
           each.
        
        ---
        
        ## 9. Concrete reference constants (verified from the datasheets)
        
        ```
        IO_BANK0_BASE = 0x40028000   # GPIOn: STATUS @ +8n, CTRL @ +8n+4 ; FUNCSEL = CTRL[4:0]
        PADS_BANK0_BASE = 0x40038000
        I2C0_BASE = 0x40090000
        I2C1_BASE = 0x40098000
        PIO0_BASE = 0x50200000
        PIO1_BASE = 0x50300000
        PIO2_BASE = 0x50400000
        
        FUNCSEL: 0=SPI 1=UART 2=I2C 3=PWM 4=SIO 5=PIO0 6=PIO1 7=PIO2
                 8..11=clk/trace/QMI/USB  31=NULL
        
        NAU88L21 I²C 7-bit addr: 0x1B (CSB=0) | 0x54 (CSB=1)
        NAU88L21 audio IF: I²S/left-justified/PCM  → implemented in RP2350 PIO
        ```
        
        ## 10. Open questions to resolve while executing
        
        - Does the REPL stay live while audio runs, or must we interrupt the callback?
        - Is there a firmware-exposed CODEC read path (avoids touching I²C at all)?
        - Which PIO instance/SM(s) run I²S, and is MCLK generated (PIO vs `clk_gpout`)?
        - Are there additional CODEC control lines (reset, IRQ/jack-detect) to map too?

[2026-07-17 16:11:32] tool result: Write
    File created successfully at: /home/agent/TE_ting/pinmapping_plan.md (file state is current in your context — no need to Read it back)

[2026-07-17 16:11:49] agent:
    I've written the plan to `./pinmapping_plan.md`. Here's the summary of what I found and what I'm proposing.
    
    ## Key realization that shapes the plan
    
    The `micropython/` checkout is **stock upstream** (origin = `micropython/micropython`, no TE board dir, no `nau88`/`codec` references). The actual CODEC bring-up lives in the compiled C modules (`ui`, `spl`, `fx`) baked into the UF2 — `rom_main.py` just calls into them. So the pin map isn't in any source we have.
    
    **But** that turns into an advantage: the running firmware has *already muxed the pins* to their I²C/I²S functions before it hands us the REPL. So instead of guess-and-test, we can just **read the RP2350's IO-mux registers live and observe the answer**. That's the backbone of the plan.
    
    ## The approaches, in priority order
    
    1. **Setup** — drive the raw REPL over `pyserial` (installed; `mpremote` isn't, but the checkout has it if needed).
    2. **Approach A — passive mux dump (primary, zero-risk):** read `IO_BANK0` `FUNCSEL` for every GPIO. `FUNCSEL==2` ⇒ I²C pins (SDA/SCL fall right out); `FUNCSEL==5/6/7` ⇒ PIO-driven = I²S candidates. Pure `mem32` reads.
    3. **Approach B — active I²C confirm:** `I2C.scan()` on the pins from A, expecting the NAU88L21's address **`0x1B`** (or `0x54`) — that both proves the pins and reveals the CSB strap.
    4. **Approach C — I²S signal ID:** read the PIO state-machine `PINCTRL`/`CTRL`/`CLKDIV` registers to label each candidate pin BCLK / LRCLK / DOUT / DIN (side-set usually carries the two clocks).
    5. **Approach D — UF2 static analysis:** disassemble the firmware to corroborate and recover aux pins (MCLK/reset/IRQ) — fallback if the REPL is uncooperative.
    
    I verified all the register bases against the RP2350 datasheet and the I²C address against the NAU88L21 datasheet, so §9 has concrete constants ready to use. Everything read-only comes first; I flagged the safety point of **not** blindly toggling pins that could fight the running CODEC.
    
    Want me to go ahead and start executing — connect to the REPL and run the Approach A register dump?