Reading and writing to I2C memories with pico.
To read and write to a I2C memory or any I2C device that need register number before data is sent or received use:
int i2c_write_mem_blocking(i2c_inst_t *i2c, uint32_t i2caddr, uint32_t addr, size_t addrsize, uint8_t *src, size_t len);
int i2c_read_mem_blocking(i2c_inst_t *i2c, uint32_t i2caddr, uint32_t addr, size_t addrsize, uint8_t *dst, size_t len);`
The addr paramater is the desired address in the I2C memory.
The addrsizeparameter is its length in bytes, the acceptable range is 1-4.
The other parameters are as in the i2c_write_blocking().
The return value is either the number of bytes written to or read from the memory, not including address bytes, or PICO_GENERIC_ERROR in case of errors, including NACK while writing the memory address.
To use this in your pico project:
- copy this directory (MemI2C) as a subdirectory of the base project directory or add it as a git submodule
- add the following line to the main CMakeLists.txt, after the
add_executable(...)statement:
add_subdirectory( MemI2C ) - At least version 3.13 of CMake is needed, make sure the main CMakeLists.txt begins with a
cmake_minimum_required(VERSION 3.13)(or later) line to correctly set policies. - use
#include "memI2C.h"as needed.