Meh...
Trying bits and pieces from all over the web for using the hardware timer, but since I'm not exactly sure what I'm doing when it comes to this level of hardware interaction - well the following crude sketch doesn't work. 
/*
RFID Lock sensor/actuator
Henrik Ekblad <henrik.ekblad@mysensors.org>
Use RFID tag to lock/unlock a door or trigger a scene on your controller.
This example sketch allows you to add an optional relay or solenoid
which can be activated/opened by RFID or controller.
Use the I2C wiring option for your RFID module and connect to the following Arduino pins.
RFID Arduino
----- -------
GND -> GND
VCC -> +5V
SCL -> A5
SDA -> A4
Use normal wiring for NRF24L01 radio
Attach a optional relay or solonoid lock to pin 4
*/
#include <MySensor.h>
#include <SPI.h>
#include <Wire.h>
#include <PN532_I2C.h>
#include <PN532.h>
#include <avr/sleep.h>
#include <avr/io.h>
#include <avr/interrupt.h>
// Add your valid rfid keys here. To find you your key just run sketch; hold your new RFID tag in fron ot the reader;
// and copy the key from serial output of this sketch.
const uint8_t maxKeyLength = 7;
uint8_t validKeys[][maxKeyLength] = {
};
int keyCount = sizeof validKeys / maxKeyLength;
#define CHILD_ID 99 // Id of the sensor child
#define YELLOWLED 5 // Pin for the Yellow led.
/*Pin definitions*/
const int lockPin = 4; // (Digital 4) The pin that activates the relay/solenoid lock.
bool lockStatus;
MySensor gw;
MyMessage lockMsg(CHILD_ID, V_LOCK_STATUS);
PN532_I2C pn532i2c(Wire);
PN532 nfc(pn532i2c);
void setup() {
pinMode(lockPin, OUTPUT);
pinMode(YELLOWLED, OUTPUT);
nfc.begin();
uint32_t versiondata = nfc.getFirmwareVersion();
if (! versiondata) {
Serial.print("Couldn't find PN53x board");
while (1); // halt
}
Serial.print("Found NFC chip PN5"); Serial.println((versiondata>>24) & 0xFF, HEX);
Serial.print("Firmware ver. "); Serial.print((versiondata>>16) & 0xFF, DEC);
Serial.print('.'); Serial.println((versiondata>>8) & 0xFF, DEC);
// Set the max number of retry attempts to read from a card
// This prevents us from waiting forever for a card, which is
// the default behaviour of the PN532.
nfc.setPassiveActivationRetries(0x3);
// configure board to read RFID tags
nfc.SAMConfig();
// Init mysensors library
gw.begin(incomingMessage);
gw.sendSketchInfo("RFID Lock", "1.0");
gw.present(CHILD_ID, S_LOCK);
lockStatus = gw.loadState(0); // Read last lock status from eeprom
setLockState(lockStatus, true); // Now set the last known state and send it to controller
// initialize Timer1
cli(); // disable global interrupts
TCCR1A = 0; // set entire TCCR1A register to 0
TCCR1B = 0; // same for TCCR1B
// set compare match register to desired timer count:
OCR1A = 15624;
// turn on CTC mode:
TCCR1B |= (1 << WGM12);
// Set CS10 and CS12 bits for 1024 prescaler:
TCCR1B |= (1 << CS10);
TCCR1B |= (1 << CS12);
// enable timer compare interrupt:
TIMSK1 |= (1 << OCIE1A);
// enable global interrupts:
sei();
}
void loop() {
gw.process(); // Process incomming messages
boolean success;
uint8_t key[] = { 0, 0, 0, 0, 0, 0, 0 }; // Buffer to store the returned UID
uint8_t currentKeyLength; // Length of the UID (4 or 7 bytes depending on ISO14443A card type)
// Wait for an ISO14443A type cards (Mifare, etc.). When one is found
// 'uid' will be populated with the UID, and uidLength will indicate
// if the uid is 4 bytes (Mifare Classic) or 7 bytes (Mifare Ultralight)
success = nfc.readPassiveTargetID(PN532_MIFARE_ISO14443A, &key[0], ¤tKeyLength);
if (success) {
Serial.print("Found tag id: ");
for (uint8_t i=0; i < currentKeyLength; i++)
{
if (i>0) Serial.print(",");
Serial.print("0x");Serial.print(key[i], HEX);
}
for (uint8_t i=currentKeyLength; i < maxKeyLength; i++)
{
Serial.print(",0x00");
}
Serial.println("");
boolean valid = false;
// Compare this key to the valid once registered here in sketch
for (int i=0;i<keyCount && !valid;i++) {
for (int j=0;i<currentKeyLength && !valid;j++) {
if (key[j] != validKeys[i][j]) {
break;
}
if (j==currentKeyLength-1) {
valid = true;
}
}
}
if (valid) {
// Switch lock status
setLockState(!lockStatus, true);
}
// Wait for card/tag to leave reader
while(nfc.readPassiveTargetID(PN532_MIFARE_ISO14443A, &key[0], ¤tKeyLength));
//gw.sleep(2000);
}
sleep();
}
// Unlocks the door.
void setLockState(bool state, bool send){
if (state) {
Serial.println("close lock");
digitalWrite(YELLOWLED, HIGH);}
else {
Serial.println("open lock");
digitalWrite(YELLOWLED, LOW);}
if (send)
gw.send(lockMsg.set(state));
digitalWrite(lockPin, state);
gw.saveState(0,state);
lockStatus = state;
}
void incomingMessage(const MyMessage &message) {
// We only expect one type of message from controller. But we better check anyway.
if (message.type==V_LOCK_STATUS) {
// Change relay state
setLockState(message.getBool(), false);
// Write some debug info
Serial.print("Incoming lock status:");
Serial.println(message.getBool());
}
}
void sleep(){
// disable ADC
ADCSRA = 0;
// clear various "reset" flags
MCUSR = 0;
// allow changes, disable reset
WDTCSR = bit (WDCE) | bit (WDE);
// set interrupt mode and an interval
WDTCSR = bit (WDIE) | bit (WDP3) | bit (WDP0); // set WDIE, and 1 second delay
wdt_reset(); // pat the dog
set_sleep_mode (SLEEP_MODE_PWR_DOWN);
noInterrupts (); // timed sequence follows
sleep_enable();
// turn off brown-out enable in software
MCUCR = bit (BODS) | bit (BODSE);
MCUCR = bit (BODS);
interrupts (); // guarantees next instruction executed
sleep_cpu ();
// cancel sleep as a precaution
sleep_disable();
}
ISR(TIMER1_COMPA_vect)
{
boolean success;
uint8_t key[] = { 0, 0, 0, 0, 0, 0, 0 }; // Buffer to store the returned UID
uint8_t currentKeyLength; // Length of the UID (4 or 7 bytes depending on ISO14443A card type)
// Wait for an ISO14443A type cards (Mifare, etc.). When one is found
// 'uid' will be populated with the UID, and uidLength will indicate
// if the uid is 4 bytes (Mifare Classic) or 7 bytes (Mifare Ultralight)
success = nfc.readPassiveTargetID(PN532_MIFARE_ISO14443A, &key[0], ¤tKeyLength);
if (success) {
Serial.print("Found tag id: ");
for (uint8_t i=0; i < currentKeyLength; i++)
{
if (i>0) Serial.print(",");
Serial.print("0x");Serial.print(key[i], HEX);
}
for (uint8_t i=currentKeyLength; i < maxKeyLength; i++)
{
Serial.print(",0x00");
}
Serial.println("");
boolean valid = false;
// Compare this key to the valid once registered here in sketch
for (int i=0;i<keyCount && !valid;i++) {
for (int j=0;i<currentKeyLength && !valid;j++) {
if (key[j] != validKeys[i][j]) {
break;
}
if (j==currentKeyLength-1) {
valid = true;
}
}
}
if (valid) {
// Switch lock status
setLockState(!lockStatus, true);
}
// Wait for card/tag to leave reader
while(nfc.readPassiveTargetID(PN532_MIFARE_ISO14443A, &key[0], ¤tKeyLength));
//gw.sleep(2000);
}
}
Help is appreciated...
