Remote Node Reset

[diggs]

I have a requirement where I will be running a sensor in a remote location that I will not have physical access to for several weeks. I will have remote access via either port forwarding on the remote network or using weaved on the PI.

http://www.weaved.com/in-action/weaved-iot-kit

The issue I have is that from time to time, a node may lock-up and stop communicating (often due to a noisy electrical environment). While it is not a common thing, I cannot afford to lose comms with the node, so I am after a way to either

1. have the node reboot at some specific time or some type of watchdog system on board to do this

2. a way to reboot the node remotely when I see it not responding anymore

Any suggestions, tips and pointers appreciated. If I had to change controller for this specific project I could consider that, but must have the remote access.

Setup

Raspberry PI
Serial Gateway
Moisture Detection Sensor
NRF24 Radio
Domoticz Controller
Weaved (http ssh access)

[Sparkman]

@diggs Arduino's have built in watch-dog timers which you can activate for your sensor. Just google "Arduino watchdog timer" and you'll see lots of examples. If that won't work for you, you can also build a hardware watchdog timer using a 555 chip, a diode, and a few resistors/capacitors. I've built one one a breadboard and it works great. Here's an example of one of those: http://www.playwitharduino.com/?p=291

Cheers
Al

[AWI]

In addition you should make sure that you take similar measure with the Pi. The chance that it locks up is a lot bigger than a simple node. If you reboot (via watchdog, documented in Domoticz wiki) the gateway will do a reset too. To avoid power issues I usually power these nodes through an USP/ battery. You could use a "Power bank" and make sure to add a solid capacitor (> 470 uF) as these things make al lot of "noise" themselves. (a Pi would need a 1A output minimum).

[diggs]

@awi @Sparkman

Thanks guys, will implement these and see how it goes