[Lab] ESP8266 issues and data logger (Ken McKinnon)

[Adrian Jones]

Ken,
You raise an interesting idea but I'm not sure that this is required. 
Watchdog timers are great if the Arduino misbehaves. However, the issue I
have is that it is the ESP8266 that  gets stuck in a loop, not the Arduino.
When it is in this 'stuck' state, subsequent AT commands to the ESP8266
throw errors (which I can capture) and this is a good indication that it
needs resetting.
 
I already use an Arduino pin (via Schottky diode and 10k pull-up to 3.3V) to
force a reset of the ESP8266 during the setup. This leaves it in a known
state before I start sending AT commands to it. I have now added code to
force a reset if 10 errors are seen in succession. This should address the
problem.

------------------------------

Message: 5
Date: Sun, 07 Dec 2014 15:32:15 -0500
From: Ken McKinnon <klmckinnon at rogers.com>
To: lab at artengine.ca
Subject: Re: [Lab] [Bulk] Re:  ESP8266 issues and data logger
Message-ID: <5484B94F.6040206 at rogers.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Sounds like you need to add a watchdog function, something that sits outside
the main code that gets tweaked once in a while and if it doesn't it will
cause a reset.

https://www.youtube.com/watch?v=BDsu8YhYn8g

The Watchdog has a separate timer that ticks over at a set rate, if it
overflows, it will force a reset.  The working code within your cycle
periodically would have to clear the WDT thereby preventing it from an
unplanned reset.

It can also be done externally.

Ken