[Tinyos-help] Connecting PCF8563 RTC to Iris

[Janos Sallai]

Andres,

I2CPacket.read and I2CPacket.write are split phase operations. You
have to wait for the corresponding readDone or writeDone events before
issuing the next read or write, otherwise the subsequent operations
may fail.

Janos

On Wed, Jul 29, 2009 at 7:22 AM, Andres Vahter<andres.vahter at gmail.com> wrote:
> Hi,
> I'm tryng to connect PCF8563 real time clock to Iris using I2C.
> http://www.datasheetcatalog.com/datasheets_pdf/P/C/F/8/PCF8563.shtml
> I'm not sure how to read and write time values.
> Here is a tutorial how to do it with bus pirate:
> http://hackaday.com/2009/06/26/parts-i2c-real-time-clock-calendar-pcf8563/
> And here is another example from
> http://www.nxp.com/acrobat_download/applicationnotes/AN_pcf8563-73-83-93_real_time_clock.pdf
>
> Setting the clock is a straight forward procedure, setting first the mode
> and
> then the actual time: e.g Friday, July 16 1999, 2’45 pm
> Binary Hex,addr,comments
> generate I2C-bus start condition
> 1 0 1 0  0 0 1 W A2 slave address
> 0 0 0 0  0 0 0 0 00 word address 0, next bytes are data
> 0 0 0 0  0 0 0 0 00 00 control/status1, no test modes or POR override
> 0 0 0 0  0 0 0 0 00 01 control/status2, no alarm/timer flags and interrupts
> 0 0 0 0  0 0 0 0 00 02 setting seconds clear the voltage low detector
> 0 1 0 0  0 1 0 1 45 03 setting minutes
> 0 0 0 1  0 1 0 0   14 04 setting hours to 14
> 0 0 0 1  0 1 0 1 16 05 setting days  to 16
> 0 0 0 0  0 1 0 1 03 06 setting weekdays to Friday
> 1 0 0 0  0 1 1 1 07 07 setting month to 7 and century bit to 1
> 1 0 0 1  1 0 0 1 99 08 setting years to 99
> 1 0 0 0  0 0 0 0 80 09 alarm values reset to 00
> 1 0 0 0  0 0 0 0 80 0A alarm values reset to 00
> 1 0 0 0  0 0 0 0 80 0B alarm values reset to 00
> 1 0 0 0  0 0 0 0 80 0C alarm values reset to 00
> 1 0 0 0  0 0 0 0 00 0D setting frequency out to 32768Hz e.g. for tuning
> 0 0 0 0  0 0 0 0 00 0E timer switched off
> generate I2C-bus stop condition
> How to do it in TinyOS 2? Here's what I did:
> ---------NodeC.nc-----------------------------
> module NodeC {
> .........
> uses interface Boot;
> uses interface AMSend as Send;
> uses interface Leds;
> uses interface Resource;
> uses interface I2CPacket<TI2CBasicAddr> as I2C;
> .......
> uint8_t buffer[4]; // write
> uint8_t rbuffer[4]; // read
> .....
> event void Boot.booted() {
> call Resource.request(); // RTC i2c
> }
>
> event void Resource.granted() {
> buffer[0] = 0xA2;
> buffer[1] = 0x00;
> buffer[2] = 0xF;
> buffer[3] = 0x00;
>
> // Init time
> if (call I2C.write(I2C_START | I2C_STOP, 0xA2, sizeof(uint8_t), &buffer[0])
> == SUCCESS) {
> }
> // write to control status 1
> if (call I2C.write(I2C_START | I2C_STOP, 0x00, sizeof(uint8_t), &buffer[0])
> == SUCCESS) {
> }
> // init seconds to 15
> if (call I2C.write(I2C_START | I2C_STOP, 0x02, sizeof(uint8_t), &buffer[2])
> == SUCCESS) {
> }
> // Read time
> if (call I2C.write(I2C_START | I2C_STOP, 0xA3, sizeof(uint8_t), &buffer[0])
> == SUCCESS) {
> call Leds.led2On();
> }
> if (call I2C.read(I2C_START | I2C_STOP, 0x02, sizeof(uint8_t), &rbuffer[0])
> == SUCCESS)
> // call Leds.led1On();
> dateAndTime = rbuffer[0];
> }
> async event void I2C.readDone(error_t error, uint16_t addr, uint8_t length,
> uint8_t* data) {
> }
> async event void I2C.writeDone(error_t error, uint16_t addr, uint8_t length,
> uint8_t* data) {
> call Leds.led2On();
> }
> I'm confused about addresses. I2C write address is 0xA2 and read address
> 0xA3.
> How to just send 0xA2 to I2C like in pseudo code:
> 1 0 1 0  0 0 1 W A2 slave address (how to send it)?
> 0 0 0 0  0 0 0 0 00 word address 0, next bytes are data
> 0 0 0 0  0 0 0 0 00 00 control/status1, no test modes or POR override (how
> this should be sent - it's little different from first line?)
> Do I have to always send data to address 0xA2 and seconds address must be
> also in buffer[2] when I want to init it to for example 15?
> Should I call:
> buffer[2] = addr + init value (02+0xF)
> call I2C.write(I2C_START | I2C_STOP, 0xA2, sizeof(uint8_t), &buffer[2]) ==
> SUCCESS)
> Any hints how PCF8563 should be used with TinyOS2 on Iris mote?
>
> Andres Vahter
>
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