Mark,

it's only single false peaks with max offsets around 1.0 V, and the false readings are always on the low side. That's what lead me to assuming it's the A/D hold capacitor charge time.

Example:

12,8
12,8
12,8
11,8
12,8
12,8
12,8

My filtering solution (damping by 1:1 averaging with last reading, see net.c line 1394) has been sufficient up to now, so I don't think we need to use additional RAM for this. If the peaks would be higher off we could try another damping ratio first, 2:1 for example.

Regards,
Michael
Am 30.04.2013 04:56, schrieb Mark Webb-Johnson:

On the 12v filtering, all I can think is to average it, perhaps over a minute, or for a set number of readings. Or perhaps require 2 readings higher than the current reading before increasing it (or generally 2 readings before it is changed). This could be done in the function to handle reading the value.

For example, say we kept a total, a count and the last value. Then, input_voltage() would read the value, add it to the total and increment the count. If count > 5 (say), set last value = total / count, then reset total,count=0. It would return last value as the result.

Do you have any historical list of the values reported from the function? Does it go 11.5, 11.6, 11.5, 11.5, 13.2, 11.5, 11.6, etc? Of stay falsely high for multiple readings?

Regards, Mark.
On 28 Apr, 2013, at 11:06 PM, Michael Balzer wrote:
I just checked in my fix for the USSD reply handler. My tests with streaming enabled did not produce any more crashes, so I think that was the problem.

My tests show there still is an issue with streaming enabled: if I let a client open (perl / App), very few GPS points now get through, both to the App and to the GPS log. Could be due to the modem not getting the per second GPS requests or due to some msg queue issue. I'll debug that ASAP.

I also reactivated the 12V input filtering as the false peaks still occur and I've got no more ideas for the A/D conversion. Any hint on this is appreciated.

Regards,
Michael 


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