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Re: [Paparazzi-devel] Problem of Tiny2.11 board, ADC and LPC2148, needs
Re: [Paparazzi-devel] Problem of Tiny2.11 board, ADC and LPC2148, needs help
Fri, 24 Apr 2009 18:32:02 +0300
Thunderbird 188.8.131.52 (X11/20090318)
The LPC2148 should get mildly warm after a while. Definitely not hot
after a few minutes. Sounds like something is sinking a lot of current.
Have you followed the traces and made sure there are no shorts? Are any
of your ADCs working?
Just a few ideas to check
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.
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