hardware

name hardware description Read and control I2C and SPI peripherals on Sipeed boards (LicheeRV Nano, MaixCAM, NanoKVM). homepage https://wiki.sipeed.com/hardware/en/lichee/RV_Nano/1_intro.html metadata {"nanobot":{"emoji":"🔧","requires":{"tools":"[Truncated]"}}} 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)