Devantech Thermal Array

[jj9867]

Hi,

I am trying to get a Devantech Thermal Array Sensor TPA81 to work with my Picc 16f690 micro controller I am using the following code:

#include "thermal.h"

BYTE address,data[10];
BYTE readdata;
int count, current, high;
int16 delay;

BYTE readthermal(int address)
{
i2c_start();
delay_ms(10);
i2c_write(0xD0); // Device address
delay_ms(10);
i2c_write(address); // Data to device
delay_ms(10);
i2c_start(); // Restart
delay_ms(10);
i2c_write(0xD1); // to change data direction
delay_ms(10);
readdata = i2c_read(5); // Now read from slave
delay_ms(10);
i2c_stop();

return readdata;

}

void main()
{

//setup_adc_ports(NO_ANALOGS|VSS_VDD);
//setup_adc(ADC_OFF);
//setup_timer_0(RTCC_INTERNAL|RTCC_DIV_1);
//setup_timer_1(T1_DISABLED);
//setup_timer_2(T2_DISABLED,0,1);

//setup_oscillator(OSC_8MHZ);

// now we must read this sucker
delay_ms(10000);

while(1 == 1)
{

address = 1;

while(address < 10)
{
data[address] = readthermal(address);
address++;
}


//count = 1;
//current = data[0];
//high = 0;
delay =800;

set_tris_c(0);
output_c(data[1]);
delay_ms(delay);
output_c(0b00000101);
delay_ms(delay);
output_c(data[2]);
delay_ms(delay);
output_c(0b00000101);
delay_ms(delay);
output_c(data[3]);
delay_ms(delay);
output_c(0b00000101);
delay_ms(delay);
output_c(data[4]);
delay_ms(delay);
output_c(0b00000101);
delay_ms(delay);
output_c(data[5]);
delay_ms(delay);
output_c(0b00000101);
delay_ms(delay);
output_c(data[6]);
delay_ms(delay);
output_c(0b00000101);
delay_ms(delay);
output_c(data[7]);
delay_ms(delay);
output_c(0b00000101);
delay_ms(delay);
output_c(data[8]);
delay_ms(delay);
output_c(0b00000101);
delay_ms(delay);
output_c(data[9]);
delay_ms(delay);
output_c(0b00000101);
delay_ms(delay);
output_c(0b11111111);
delay_ms(delay);


//while (count < 9)
//{
// if (current < data[count])
// {
// current = data[count];
// high = count;
// }
// count = count + 1;
//}

// set_tris_c(0);
// output_c(high);

}





}


really the important part of the code is the function that is supposed to read the thermal array one register at a time.

I am running this with LED's on each of the C pins. The only output I get from this program is 11111100. I am new to the whole I2C bus, but I have never had this problem when interfacing with a device. Normally the above code works without problems.

Any help would be great,
Thanks
JJ

[PCM programmer]

[jj9867]

The stream address matched the one in the header file but I did not realize not to send the acknowledge bit....

Without that the sensor works flawlessly

Thanks
JJ