/**
* Set's up a pin for interrupt. uses arduino MODEs: CHANGE, FALLING, RISING.
*
* Note that the interrupt condition finishes when you read the information about the port / value
* that caused the interrupt or you read the port itself. Check the datasheet can be confusing.
*
*/
void MCP23017::setupInterruptPin(uint8_t pin, uint8_t mode) {
// set the pin interrupt control (0 means change, 1 means compare against given value);
updateRegisterBit(pin,(mode!=CHANGE),MCP23017_INTCONA,MCP23017_INTCONB);
// if the mode is not CHANGE, we need to set up a default value, different value triggers interrupt
// In a RISING interrupt the default value is 0, interrupt is triggered when the pin goes to 1.
// In a FALLING interrupt the default value is 1, interrupt is triggered when pin goes to 0.
updateRegisterBit(pin,(mode==FALLING),MCP23017_DEFVALA,MCP23017_DEFVALB);
// enable the pin for interrupt
updateRegisterBit(pin,HIGH,MCP23017_GPINTENA,MCP23017_GPINTENB);
}
void MCP23017::pullUp(uint8_t p, uint8_t d) {
updateRegisterBit(p,d,MCP23017_GPPUA,MCP23017_GPPUB);
}
void RFduinoProXShield::pullUp(uint8_t p, uint8_t d) {
updateRegisterBit(p,d,MCP23017_GPPUA,MCP23017_GPPUB);
}
/**
* Sets the pin mode to either INPUT or OUTPUT
*/
void MCP23017::pinMode(uint8_t p, uint8_t d) {
updateRegisterBit(p,(d==INPUT),MCP23017_IODIRA,MCP23017_IODIRB);
}
/**
* Sets the pin mode to either INPUT or OUTPUT
*/
void RFduinoProXShield::pinMode(uint8_t p, uint8_t d) {
updateRegisterBit(p,(d==INPUT),MCP23017_IODIRA,MCP23017_IODIRB);
}
