Reliability test results: Pyboard D and MQTT

[pythoncoder]

tl;dr For serious reliability the Pyboard D seems to be the best platform for WiFi applications.

Using the asynchronous resilient MQTT mqtt_as.py in this repo I am running long term tests. To date these have accumulated 30 days running in one location with RSSI -56dB and 14 days in another with RSSI -83dB - in our garden shed far from the AP.

These tests are still running without failure. There is no watchdog timer in use.

The test script exchanges messages every 5s with qos==1. The library performs re-publications in the event of WiFi disruption and recovers from WiFi outages with no qos==1 data loss. The test script reports outages as seen by the Pyboard and also maintains and reports the repub count.

At the -56dB location in 30 days two outages occurred with four repubs - in over 500K publications. At the -83dB location in 14 days it saw one outage and 21 repubs.

I have no comparable quantitative data for ESP8266 or ESP32 but I have done a good deal of testing with them. The ESP8266 in particular experiences outages much more frequently. I believe it occasionally crashes, necessitating a WDT, but intend to re-test to confirm this.

If anyone wishes to replicate these tests it is vital to have a high quality power supply. Some USB wall-warts are poor and cause crashes on any platform.

[kevinkk525]

That sounds promising. -83dBm is a quite weak signal.
Thanks for all your testing efforts and patience!

[tve]

Is your code available somewhere? I'd be interested in testing using an esp32...

[pythoncoder]

The resilient MQTT repo is here. It has been tested on ESP32 for resilience, but the long term tests have so far included only Pyboard D and ESP8266.

[tve]

I'm aware of the repo, but when you write "The test script exchanges messages every 5s with qos==1" which script do you specifically run?

[pythoncoder]

I run this one on the unit under test. The mosquitto broker runs on a Raspberry Pi, and I run mosquitto_sub on the Pi to display the results. Another terminal on the Pi runs this script to provide messages for the unit's subscription.

The Pi is just a Linux box which is economical to run 24/7 - any networked Linux box will do.