I have a perplexing problem with an 18A.
At seemingly random intervals it appears to freeze or lock up.
- the program downloads ok
- for 98% of the time the code seems to operate ok
What happens is that an output that should be pulsing (on 50ms then off 50ms) will either stay on permanently or off permanently when the problem occurs.
Given the code in the 18A, this cannot happen.
At the same time, the 18A will no longer receive serial in commands from a 40X that continues to operate satisfactorily.
The way to restore the 18A is to reset.
As I want to drive a heating element (3600W) with this control line, it is a serious concern for me.
The power supply is a switchmode PC supply. The 12V line from this is connected to an LM317 with a series resistor on its output to trickle charge (current limited) 4xAA nicads. There are no caps on input or output side of the 317, as I assumed the nicads would be more than enough buffering of spikes etc.
All chips (picaxe and other) have a 100nF cap on supply lines as is recommended. All noisy devices (like buzzer & relays) have diodes connected to prevent back EMF.
My suspicion is that this issue is power supply related because when the nicads are flat or nearly flat the problem is more prevalent.
Any suggestions as to tests or things to try out?
thanks, Arnie
At seemingly random intervals it appears to freeze or lock up.
- the program downloads ok
- for 98% of the time the code seems to operate ok
What happens is that an output that should be pulsing (on 50ms then off 50ms) will either stay on permanently or off permanently when the problem occurs.
Given the code in the 18A, this cannot happen.
At the same time, the 18A will no longer receive serial in commands from a 40X that continues to operate satisfactorily.
The way to restore the 18A is to reset.
As I want to drive a heating element (3600W) with this control line, it is a serious concern for me.
The power supply is a switchmode PC supply. The 12V line from this is connected to an LM317 with a series resistor on its output to trickle charge (current limited) 4xAA nicads. There are no caps on input or output side of the 317, as I assumed the nicads would be more than enough buffering of spikes etc.
All chips (picaxe and other) have a 100nF cap on supply lines as is recommended. All noisy devices (like buzzer & relays) have diodes connected to prevent back EMF.
My suspicion is that this issue is power supply related because when the nicads are flat or nearly flat the problem is more prevalent.
Any suggestions as to tests or things to try out?
thanks, Arnie