nsbum/esp32-mcp23008

ESP-IDF (C) driver for the MCP23008 GPIO expander

MCP23008

ESP32 component for the MCP23008 I2C GPIO expander, for use with the ESP-IDF build framework.

The ESP32 is a versatile little IoT SoC device that can handle a number of microcontroller tasks for automation and other projects. One of the problems with the ESP32 is the shortage of GPIO pins. Many of the pins on the device had dedicated functions. Some projects require a larger number of open pins. Therefore, this device and similar GPIO expanders can be used to fill the void.

The use of this component is straightfoward. If the I2C bus in use has not already been initialized, you'll need to take care of its initialization in advance of calling mcp23008_init.

esp32-mcp23008's Issues

Error on Line 165 in mcp23008_port_set_bit function

To set the bit, the operation should be |=, not &=

so, the function should be:
esp_err_t mcp23008_port_set_bit(mcp23008_t *mcp, uint8_t b) {
mcp->current |= (1 << b);
return mcp23008_write_port(mcp, mcp->current);
}
otherwise, good job on the library...

Last i2c_master_read_byte shouldn't provide ACK

in mcp23008_read_reg() the last i2c_master_read_byte() should be NACK_VAL. (line 53)

described in the documentation here:
Compared to writing data, the command link is populated in Step 4 not with i2c_master_write... functions but with i2c_master_read_byte() and/or i2c_master_read(). Also, the last read in Step 5 is configured so that the master does not provide the ACK bit.