HELP - Multiple MCP23S17

[MarcFinns]

• Arduino board: Arduino Leonardo

• Arduino IDE version 1.8.9

I built a custom board with two MCP23S17. They are on the same Chip Select, with different addresses (000 and 111). However, readGPIOAB returns the same for both chips, hence it appears I am not able to address them correctly. Reading the documentation i was under the impression this was a legit configuration. Do they require different CS? If so, what is the value of having the address pins? By the way, reset pins are connected to VCC. I did not implement a reset circuitry, which was working fine with a single IC. Help appreciated!

[bcollier94]

MarcFinns,

Don't know if you've figured it out or not, but after combing through another post the addresses are called by "0x20, 0x21, 0x22, etc." Below is code I created for testing digital reads on one chip on the 0x21 address, and you can see I called its address with "mcp1.begin_I2C(0x21);" For multiple, you would create more by calling "Adafruit_MCP23X17 mcpX;", where X is the different chips, so mcp1, mcp2, mcp3, etc. In the previous version of the library I was able to call the addresses with just "0, 1, 2, etc," but that doesn't look to be the case anymore.

//------Begin code below------

include

include

Adafruit_MCP23X17 mcp1; uint8_t state[16];

void setup() { Serial.begin(115200); Wire.begin();

mcp1.begin_I2C(0x21);

for (int i = 0; i < 16; i++){ mcp1.pinMode(i, INPUT_PULLUP); mcp1.digitalWrite(i, HIGH); }

}

void loop() { byte current[16];

for (int b = 0; b < 16; b++){ current[b] = mcp1.digitalRead(b); if (b == 15){ Serial.println(current[b]); }else{ Serial.print(current[b]); } } Serial.println(); }

[MarcFinns]

MarcFinns, Don't know if you've figured it out or not

Thanks, I did manage! With it i built a MS Flight Simulator controller with encoders, buttons and switches. Works like a charm!