5 bool i2c_initialized = 0;
6 uint8_t mcp23018_status = 0x20;
8 uint8_t init_mcp23018(void) {
9 mcp23018_status = 0x20;
13 if (i2c_initialized == 0) {
14 i2c_init(); // on pins D(1,0)
15 i2c_initialized = true;
19 /* B Pins are Row, A pins are Columns
21 mcp23018_status = i2c_start(I2C_ADDR_WRITE); if (mcp23018_status) goto out;
22 mcp23018_status = i2c_write(IODIRA); if (mcp23018_status) goto out;
23 mcp23018_status = i2c_write(0b11111111); if (mcp23018_status) goto out;
24 /* Now write to IODIRB */
25 mcp23018_status = i2c_write(0b00000000); if (mcp23018_status) goto out;
28 mcp23018_status = i2c_start(I2C_ADDR_WRITE); if (mcp23018_status) goto out;
29 mcp23018_status = i2c_write(GPPUA); if (mcp23018_status) goto out;
30 mcp23018_status = i2c_write(0b11111111); if (mcp23018_status) goto out;
31 /* Now write to GPPUB */
32 mcp23018_status = i2c_write(0b00000000); if (mcp23018_status) goto out;
37 return mcp23018_status;