Does continually reseting a 08M damage it?

[BrendanP]

Im using a 08M to handle/sort incomming RF signals. When it recieves a signal with valid header info it passes it along to a 40X1.

In order to make sure the 08M hasn't crashed I want to use a MAX705 watchdog IC with it. The picaxe will of course just sit there waiting for incomming serial data so i cant use a output on it to toggle the watchdogs input. Therefore the watchdog will reset the picaxe every 1.5 seconds. ( i think thats the max705's time out period )

Will this continual reseting of the part damage it or shorten its service life?

 

[hippy]

The 08M doesn't have a reset pin, so how would you be resetting it ?

The MAX705 Reset/WDO seem to be open-collector so can sink current but not source it. So you cannot easily control it through switching its power direct.

You could implement a similar watchdog which can power the PICAXE ( good for 25mA ) using a PICAXE 08/08M/14M instead of the MAX705. The advantage there is you can set your own timeout period. The 08 watchdog can also monitor the data from the main 08M to the 40X and abort the timeout when it sees the 08M is still alive. It can also watch the incoming RF and the 08M's output and only reset if it thinks the 08M should have sent something but didn't. That would minimise power-cycling.

I'd forget the MAX705 and use a second PICAXE to do the job.

Would rapid power-cycling damage an 08M ? It'll probably shorten its life but I wouldn't have thought drastically. The only way to tell is to try it.

 

[moxhamj]

I wouldn't have thought turning an 08M on and off would shorten its life. I have used hippy's idea of one 08M acting as a watchdog for another (for an RF project) and it resets once every 4 seconds and has been running now for a year with no problems.

 

[BrendanP]

Thanks for the input, especially for the idea of using the second picaxe. I will do as you suggest.