Picoclaw hardware

Name: hardware
Author: sipeed

Read and control I2C and SPI peripherals on Sipeed boards (LicheeRV Nano, MaixCAM, NanoKVM).

install

source · Clone the upstream repo

git clone https://github.com/sipeed/picoclaw

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/sipeed/picoclaw "$T" && mkdir -p ~/.claude/skills && cp -r "$T/workspace/skills/hardware" ~/.claude/skills/sipeed-picoclaw-hardware && rm -rf "$T"

manifest: workspace/skills/hardware/SKILL.md

Hardware (I2C / SPI)

Use the

i2c

and

spi

tools to interact with sensors, displays, and other peripherals connected to the board.

Quick Start

# 1. Find available buses
i2c detect

# 2. Scan for connected devices
i2c scan  (bus: "1")

# 3. Read from a sensor (e.g. AHT20 temperature/humidity)
i2c read  (bus: "1", address: 0x38, register: 0xAC, length: 6)

# 4. SPI devices
spi list
spi read  (device: "2.0", length: 4)

Before You Start — Pinmux Setup

Most I2C/SPI pins are shared with WiFi on Sipeed boards. You must configure pinmux before use.

See

references/board-pinout.md

for board-specific commands.

Common steps:

Stop WiFi if using shared pins:
```
/etc/init.d/S30wifi stop
```
Load i2c-dev module:
```
modprobe i2c-dev
```
Configure pinmux with
```
devmem
```
(board-specific)
Verify with
```
i2c detect
```
and
```
i2c scan
```

Safety

Write operations require
```
confirm: true
```
— always confirm with the user first
I2C addresses are validated to 7-bit range (0x03-0x77)
SPI modes are validated (0-3 only)
Maximum per-transaction: 256 bytes (I2C), 4096 bytes (SPI)

Common Devices

See

references/common-devices.md

for register maps and usage of popular sensors: AHT20, BME280, SSD1306 OLED, MPU6050 IMU, DS3231 RTC, INA219 power monitor, PCA9685 PWM, and more.

Troubleshooting

Problem	Solution
No I2C buses found	`modprobe i2c-dev` and check device tree
Permission denied	Run as root or add user to `i2c` group
No devices on scan	Check wiring, pull-up resistors (4.7k typical), and pinmux
Bus number changed	I2C adapter numbers can shift between boots; use `i2c detect` to find current assignment
WiFi stopped working	I2C-1/SPI-2 share pins with WiFi SDIO; can't use both simultaneously
`devmem` not found	Download separately or use `busybox devmem`
SPI transfer returns all zeros	Check MISO wiring and device power
SPI transfer returns all 0xFF	Device not responding; check CS pin and clock polarity (mode)