/* unit test for PortRead_MCP23S17 The setup is an MCP23S17 I/O expander on a Teensy LC controller. MCP23S17 port-A GPIO pins are not connected to anything. Port-A GPIO-pin ouputs alternate between 0 and 3.3 volts. Use a volt meter to measure port-A GPIO-pin ouputs. MCP23S17 on 3.3v does not output enough power to reliable light LEDs LED lights w/o resistor LED not light with 56 ohm resistor */ #include "PortIOE.h" #include "PortWrite_MCP23S17.h" const uint8_t PortIOE::ADDR = 0x20; //MCP23S17 address, all 3 ADDR pins are grounded PortIOE portA(0, 0); PortWrite_MCP23S17 portAWrite(portA); //PortAWrite needed for begin() const uint8_t GPIOA = 0x12; //LEDs are on port A void setup() { delay(6000); portAWrite.begin(); //Keyboard.print("start blinking"); } void loop() { portAWrite.write(~0, HIGH); //set all GPIOA pins HIGH delay(2000); portAWrite.write(~0, LOW); //set all GPIOA pins LOW delay(2000); }