[Paparazzi-devel] Problem of Tiny2.11 board, ADC and LPC2148, needs help
From:
童磊
Subject:
[Paparazzi-devel] Problem of Tiny2.11 board, ADC and LPC2148, needs help
Date:
Fri, 24 Apr 2009 20:40:16 +0800
Hi,everyone!
I got my Tiny2.11 bundle from PPZUAV,unfortunately with three faulty ir_sensors.I found out later it was because they'd been soldered with broken AD8551.I replaced the AD and fixed the sensors. Then I found the ADC_0 was not working at all.When I connected the vertical sensors to IR_V,the message window showed 0 and never changed,but a voltage around 1.625 could be measured from both ADC_0 and pin 1 on LPC2148,changing with temperature.I tried IR_V on ADC_5,with sensors covered in foam and neutral set to 0,the message reading was 484.Then I changed the neutral to 484,but the reading was not 0 but 241,no way to get a 0. When tested with ADC_3,with neutral set to 0 I got -772,but I got around 0 only when neutral was set to 512,couldn't explain why.I tested with ADC_6 and ADC_4 too,got readings about -136 and -768.I have no idea why the result were like this,everything seemed to be OK before they went into LPC2148,but the output were wrong.
I did another test,unpluged everything and checked the readings.The results were:ADC_0,ADC_5,ADC_6----0,with a voltage of 0V;ADC_1,ADC_2,ADC_3.ADC_4-----varied from 50 to 700,with a voltage varied from 0.1V~0.6v.I don't why there were still readings and even voltages on pin when nothing went in.
Another thing,the LPC2148 got somehow hot when running for a few minutes,was that normal?
Needs help with the strange results of the ADC.Since PPZUAV won't ship to China,I can't sent it back for replacement.I have to fixed it myself.