BS2p to TPA81

legoman132

I am having trouble with my BS2p and a TPA81. The TPA81 is a sensor that can read ambient temperature and 8 pixels of infrared non-contact temperature. Communication is done through an I2C interface. The BS2p can read registers 0 and 1 of the TPA81 (firmware revision and ambient temperature). However, registers 2 through 9 (the infrared temperature pixels of the sensor) read as 0. We are using two 1K resistors in series on the clock and data lines to give a value of 2K, just above what is recommended in the TPA81 manual (1.8K).

Code:

' {$STAMP BS2p}
' {$PBASIC 2.5}

temp VAR Byte
cnt VAR Byte

'DEBUG "hello" , CR
I2COUT 0, $D0, 1, [noparse][[/noparse]80]
DO
cnt = cnt + 1 'increment cnt
DEBUG HOME, DEC cnt, CR
I2CIN 0, $D0, 0, [noparse][[/noparse]temp] 'read register 0
DEBUG DEC temp, CR
PAUSE 125
I2CIN 0, $D0, 1, [noparse][[/noparse]temp]
DEBUG DEC temp, CR
PAUSE 125
I2CIN 0, $D0, 2, [noparse][[/noparse]temp]
DEBUG DEC temp, CR
PAUSE 125
I2CIN 0, $D0, 3, [noparse][[/noparse]temp]
DEBUG DEC temp, CR
PAUSE 125
I2CIN 0, $D0, 4, [noparse][[/noparse]temp]
DEBUG DEC temp, CR
PAUSE 125
I2CIN 0, $D0, 5, [noparse][[/noparse]temp]
DEBUG DEC temp, CR
PAUSE 125
I2CIN 0, $D0, 6, [noparse][[/noparse]temp]
DEBUG DEC temp, CR
PAUSE 125
I2CIN 0, $D0, 7, [noparse][[/noparse]temp]
PAUSE 125
DEBUG DEC temp, CR
PAUSE 125
I2CIN 0, $D0, 8, [noparse][[/noparse]temp]
DEBUG DEC temp, CR
PAUSE 125
I2CIN 0, $D0, 9, [noparse][[/noparse]temp]
DEBUG DEC temp, CR
PAUSE 125
I2COUT 0, $D0, 0, [noparse][[/noparse]cnt]
LOOP

This code reads all nine registers and writes to the first, which sets the position of a servo connected to the TPA81's servo port (meant for a panning head). You cannot read the position of the servo back.

Mike Green

You need to supply at least a link to the manual. Can't help you without a manual.

JimK

Did a quick Google search and found this link which may help:

http://www.robot-electronics.co.uk/acatalog/tpa81bs2p.htm

legoman132

Heres the manual :www.robot-electronics.co.uk/htm/tpa81tech.htm

legoman132

I tried the things recommended in the link but it still didn't work.

Franklin

Exactly what did you try and what were the results? If it is supposed to work and it does not then something is broken or you did something wrong. Now which one is it?

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- Stephen

legoman132

First, I hooked the TPA81 to the BOE's five volt supply and ground. Then I ran the SDA line to P0 and the SCL line to SCL. Next I put a 4.7K resistor from +5V to SCL and another resistor from +5 to SDA (+5V being the output of the BOE 5-volt regulator). Then I loaded the sample code for the BS2p from www.robot-electronics.co.uk/acatalog/tpa81bs2p.htm into the BS2p and ran it. The firmware revision and abient temperature gave 7 and 17, respectively. All the pixels read as 000.