Picaxe stops operating

friis

Senior Member
Hi,
I have a setup where a sensor measures the humidity of earth, send signals to a Picaxe14M2 which then activates a valve that supplies water or stops the flow accordingly.
I monitor the Picaxe by having wires sending signals to A27/my PC screen or alternatively having the Picaxe sending signals wirelessly to a snooper which then shows the result on the PC screen.
I have experienced that the Picaxe stops operating - using both methods. I then go and measure the voltage on the Picaxe and it is 4.43 volts. After I have measured the voltage, the Picaxe starts operating.
It is a big problem if the PIcaxe can stop operating and then be restarted by an external signal like measuring the voltage.
Can anyone explain that?
best regards
torben
 

lbenson

Senior Member
Post your circuit (preferably with a photo as well) and your code. With a reliable power supply, a picaxe will run for years--I have a number which have done so (or at least I have never seen an indication that they have not).
 

friis

Senior Member
Hi,
I may add, that shortly after the restart, the Picaxe again stopped operating
torben
 

hippy

Senior Member
The only things I can think of is the PICAXE is waiting for something which never arrives, or there's some kind of power glitch or brown-out or electrical noise which is knocking it off kilter.

I'm not sure why measuring the voltage would be enough to wake it up, but it could be causing a voltage drop or edge enough to kickstart the PICAXE, or getting close to the PICAXE is being picked-up and doing that.

You could add a 'Restarted' SERTXD or send that over wireless when it starts up. That would allow you to tell if measuring the supply is causing it to reset.

Littering the code with SERTXD commands may let you know where it has got to when it stops which may give an idea of what's causing the issue. Posting your code will help people to guess why it may be stopping.
 

premelec

Senior Member
Intermittent connections? Floating input pin? Noise on input pin... Put an output on the program to seeif it stops at same place or random... NOTE that programming input pin must be tied down by resistor - try adding DISCONNECT command... q.v. ...
 
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friis

Senior Member
Hi everybody,
It was, rather embarrasing, a pgm error. I had not allowed enough time for pwr-up the HC-12 before the pgm started transmitting. The pgm had worked for days without the error showing itelf - my feeble excuse. I hope that I am OK now.
Thank you everybody
torben
 

friis

Senior Member
Hi,
There was (also) a problem with a weak soldering in the GND wire hidden under a shrink tube.
torben
 
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