Phase 0 — USB, detect, erase¶

Get the PC talking to the board, prove it’s an N16R8, wipe flash so Phase 1 starts clean.

Before this: Prerequisites — packages + PlatformIO installed (pio / esptool on your PATH).

Firmware¶

Chip is empty after erase. No phase folder under firmware/ yet — Phase 1 adds 01-hello/. Tracker: Firmware.

flowchart LR
  PC[Linux PC] -->|data USB-C| COM[COM CH343]
  COM --> S3[ESP32-S3]
  S3 --> Flash["16MB flash"]

0.1 Serial permissions (once per machine)¶

From the repo root:

sudo ./scripts/setup-linux-usb.sh

Installing udev rules → /etc/udev/rules.d/99-platformio-udev.rules
…
Setup complete.

Confirm:

groups | grep dialout
test -f /etc/udev/rules.d/99-platformio-udev.rules && echo udev_ok

dialout
udev_ok

Log out/in (or reboot) if dialout was just added, then unplug/replug the board.

0.2 Detect the board¶

Plug the COM Type-C (UART/CH343), not the USB-OTG jack.

lsusb
ls -la /dev/ttyACM* /dev/serial/by-id/
pio device list

Bus 001 Device 103: ID 1a86:55d3 QinHeng Electronics USB Single Serial
crw-rw-rw- 1 root dialout … /dev/ttyACM0
…/by-id/usb-1a86_USB_Single_Serial_5CE5196417-if00 -> ../../ttyACM0

/dev/ttyACM0
------------
Hardware ID: USB VID:PID=1A86:55D3 SER=5CE5196417 LOCATION=1-1:1.0
Description: USB Single Serial

0.3 Chip and flash size¶

~/.platformio/penv/bin/esptool --chip esp32s3 --port /dev/ttyACM0 chip-id
~/.platformio/penv/bin/esptool --chip esp32s3 --port /dev/ttyACM0 flash-id

Connected to ESP32-S3 on /dev/ttyACM0:
Chip type:          ESP32-S3 (QFN56) (revision v0.2)
Features:           … Embedded PSRAM 8MB (AP_3v3)
Crystal frequency:  40MHz
MAC:                28:84:85:8c:d0:40
…
Detected flash size: 16MB
Flash type set in eFuse: quad (4 data lines)
Flash voltage set by eFuse: 3.3V

Item	This board (N16R8)
Chip	ESP32-S3 rev v0.2
Flash	16MB
PSRAM	8MB
MAC	`28:84:85:8C:D0:40`

0.4 Erase flash¶

Warning

erase-flash wipes everything on the chip. Only run it once /dev/ttyACM0 is confirmed above.

~/.platformio/penv/bin/esptool --chip esp32s3 --port /dev/ttyACM0 erase-flash

Erasing flash memory (this may take a while)...
Flash memory erased successfully in 2.3 seconds.
Hard resetting via RTS pin...

Checkpoint¶

[x] dialout + udev rules in place
[x] /dev/ttyACM0 appears (1a86:55d3)
[x] chip-id / flash-id say ESP32-S3, 16MB flash, 8MB PSRAM
[x] erase-flash finishes cleanly
[x] Lab log

Next: Phase 1 — Hello flash