[Tinyos-help] Connecting PCF8563 RTC to Iris

[Andres Vahter]

I got little furher.
Now I know that 7 bit address must be used. Instead of 0xA2, 0x51 must  
be used. I2C component shifts it to left and adds R/W bit.



module NodeC {
	uses interface Boot;
	uses interface Resource;
	uses interface I2CPacket<TI2CBasicAddr> as I2C;
................
	uint8_t  i2cState=0;
	uint8_t buffer[17];
................

	event void Boot.booted() {
		call Resource.request();	// RTC i2c
	}
	event void Resource.granted() {
		buffer[0] = 0x00;		// word address 0, next bytes are data, memory  
address is auto incremented
		buffer[1] = 0x00;		// 00 control/status1, no test modes or POR  
override
		buffer[2] = 0x00; 		// 01 control/status2, no alarm/timer flags and  
interrupts
		buffer[3] = 0x02; 		// 02 setting seconds clear the voltage low  
detector
		buffer[4] = 0x05; 		// 03 setting minutes
		buffer[5] = 0x14;		// 04 setting hours
     		buffer[6] = 0x03;		// 05 setting date
		buffer[7] = 0x06;		// 06 setting day of week
		buffer[8] = 0x04;		// 07 setting century and months
		buffer[9] = 0x09;		// 08 setting years
		buffer[10] = 0x80;		// 09 setting minute alarm
		buffer[11] = 0x80;		// 0A setting hour alarm
		buffer[12] = 0x80;		// 0B setting day alarm
		buffer[13] = 0x80;		// 0C setting weekday alarm
		buffer[14] = 0x83;		// 0D setting weekday alarm
		buffer[15] = 0x00;		// 0E timer control
		buffer[16] = 0x00;		// 0F timer

		i2cState = 0;
		call I2C.write(I2C_START | I2C_STOP, 0x51, 17, buffer);  // 0xA2 >> 1
		
	}
	async event void I2C.writeDone(error_t error, uint16_t addr, uint8_t  
length, uint8_t* data) {
		
		// page 16 fig 15.
		if(i2cState == 0){
			buffer[0] = 0x02;		// seconds - register address
			i2cState = 1;
			
			call I2C.write(I2C_START, 0x51, 1, &buffer[0])
			
			
		}
		else if(i2cState == 1){
			buffer[0] = 0x00;		// not needed - how to send no data?
			i2cState = 2;
			
			call I2C.read(I2C_START | I2C_STOP, 0x51, 1, &buffer[0])
		}
	}	
	async event void I2C.readDone(error_t error, uint16_t addr, uint8_t  
length, uint8_t* data) {
		uint16_t val;
	   	val = data[3];
	
	..................
	}


I have a question about I2C.readDone *data value. What it contains?
It doesn't return only requested register value?
I can see that data[3] contains seconds, data[4] minutes etc - it  
contains the same values what I initalized in Resource.granted() event .
Why it is so, why doesn't it contain just what I have requested?
Actually I think my reading logic is faulty.

According to http://www.datasheetcatalog.com/datasheets_pdf/P/C/F/8/PCF8563.shtml 
  page 16 fig 15. master must send no data after slave read address.
Can I do it with I2CPacket.read? As I can see it can not send no data  
to slave read address.

Read sequence ( page 16 fig 15 ):
START | SLAVE ADDRESS Write(0xA2) || ack || WORD ADDRESS || ack ||  
SLAVE ADDRESS Read (0xA3) || ack || DATA | STOP

How do to that reading part - should I use lower level I2C components  
or is it possible to do it with I2CPacket?


Andres Vahter