problem reading barometric sensor on B1-R1-A board

[lmamakos]

I'm having problems getting good data trying to read the barometric pressure sensor on the B1-R1-A board.

When I attempt to read the VAD pin, the voltage reading that I get back is 10.23V, which is 0x03FF in the result. I'm pretty sure the code that's reading the sensor is working, as I can get a temperature reading that looks OK; I can read the 2438 VAD voltage on two temperature/humidity sensors OK. Also, when I move the jumper on the board between pins 1 & 2 and measure the calibration voltage, I get a reasonable 3.45V measurement.

I'm powering it with a power injector, measuring VDD with the 2438 give me 4.93V, which seems pretty reasonable. I'm using an HA7Net to drive the 1-wire bus, and one of the H/T/S boards is daisy-chained on the same leg, a few inches away.

Any ideas on what's going on, or what I might try next?

Unfortunately, the board is about 180 miles from me at the moment (of course), and it will be hard to fiddle with the hardware first-hand. If I was there, I'd drop a voltmeter on the sensor output and verify the +12V output of the regulator..

louie

 

[stevendt]

Louie,

this is not going to be much help if you're 180 miles away......but I'd suggest a failed humidity sensor.

I got the same (10.23) volt reading from a new T/H sensor and returned it for replacement. Eric did not have time to do much testing, but we agreed that the humidity sensor was proably faulty.

regards
Dave

I'm having problems getting good data trying to read the barometric pressure sensor on the B1-R1-A board.

When I attempt to read the VAD pin, the voltage reading that I get back is 10.23V, which is 0x03FF in the result. I'm pretty sure the code that's reading the sensor is working, as I can get a temperature reading that looks OK; I can read the 2438 VAD voltage on two temperature/humidity sensors OK. Also, when I move the jumper on the board between pins 1 & 2 and measure the calibration voltage, I get a reasonable 3.45V measurement.

I'm powering it with a power injector, measuring VDD with the 2438 give me 4.93V, which seems pretty reasonable. I'm using an HA7Net to drive the 1-wire bus, and one of the H/T/S boards is daisy-chained on the same leg, a few inches away.

Any ideas on what's going on, or what I might try next?

Unfortunately, the board is about 180 miles from me at the moment (of course), and it will be hard to fiddle with the hardware first-hand. If I was there, I'd drop a voltmeter on the sensor output and verify the +12V output of the regulator..

louie

 

[lmamakos]

I've finally made it back out to the site with the funky BR-R1-A board, and my first bit of testing by moving the calibration jumper seems to indicate that the A/D converter is working fine. I got from a reading of 10.23V to a much more reasonable calibration value of 3.45V:
[codebox]
2008/10/11 19:11:22 EDT] C7000000BC85DB26 Status: 0/00 Temp:17.34(63.22F)= 17/5811 Voltage:10.230000=1023/FF03
[2008/10/11 19:11:22 EDT] C7000000BC85DB26 Status: 0/00 Temp:17.34(63.22F)= 17/5811 Voltage:4.950000= 495/EF01
[2008/10/11 19:11:22 EDT] sensor C7000000BC85DB26 returns temperature=63.22/63.22 VAD=10.230 VDD=4.950 Basement Barometer 2438(2438)


[2008/10/11 19:14:22 EDT] C7000000BC85DB26 Status: 0/00 Temp:17.41(63.33F)= 17/6811 Voltage:3.450000= 345/5901
[2008/10/11 19:14:22 EDT] C7000000BC85DB26 Status: 0/00 Temp:17.47(63.44F)= 17/7811 Voltage:4.950000= 495/EF01
[2008/10/11 19:14:22 EDT] sensor C7000000BC85DB26 returns temperature=63.33/63.44 VAD=3.450 VDD=4.950 Basement Barometer 2438(2438)
[/codebox]

So it looks like something funky with the sensor or the PC board. I'll remove it, and bring it home for further examination. Any ideas?

Louie,

this is not going to be much help if you're 180 miles away......but I'd suggest a failed humidity sensor.

I got the same (10.23) volt reading from a new T/H sensor and returned it for replacement. Eric did not have time to do much testing, but we agreed that the humidity sensor was proably faulty.

regards
Dave

I'm having problems getting good data trying to read the barometric pressure sensor on the B1-R1-A board.

When I attempt to read the VAD pin, the voltage reading that I get back is 10.23V, which is 0x03FF in the result. I'm pretty sure the code that's reading the sensor is working, as I can get a temperature reading that looks OK; I can read the 2438 VAD voltage on two temperature/humidity sensors OK. Also, when I move the jumper on the board between pins 1 & 2 and measure the calibration voltage, I get a reasonable 3.45V measurement.

I'm powering it with a power injector, measuring VDD with the 2438 give me 4.93V, which seems pretty reasonable. I'm using an HA7Net to drive the 1-wire bus, and one of the H/T/S boards is daisy-chained on the same leg, a few inches away.

Any ideas on what's going on, or what I might try next?

Unfortunately, the board is about 180 miles from me at the moment (of course), and it will be hard to fiddle with the hardware first-hand. If I was there, I'd drop a voltmeter on the sensor output and verify the +12V output of the regulator..

louie