In the late summer of 2020 the university allowed us to return, in a covid-secure manner, to our lab. The plan for our sea trials was back on. Now instead of working solely from home, or being full-time in the lab, we could take a pragmatic approach to progressing the hardware and software development.
Gateway and Sensor Nodes
A gateway node was needed to relay data from various underwater environmental sensors back to shore. For example, the marine animal detectors send data messages hourly via acoustic modem, then the gateway relays these via radio back to shore where they can then be analysed in near real-time.
When development of the new data gateway node was in full flow, I was able to: update firmware on the gateway node; send messages through our underwater test tank to its acoustic modem; and finally receive the resultant radio messages on a nearby server. All accessed through remote desktop from home. This set-up supported the iterative turnaround of “code, upload, test, and repeat” that we use in a normal environment. It really accelerated the development process.
There is more information about the MicroPython PYBD that we are using found at: https://pybd.io/hw/pybd_sfxw.html
Much of the software development and testing could be done from home. The addition of a remotely connected ammeter and voltmeter would have made some of the work around power usage a bit easier.
Finally, there is a simple transducer suspended in the test tank and connected via a soundcard to the PC. This provides a window into the acoustic world to visualise the communications between NM3 modems.
Development continues on sensor nodes and incorporating further network protocols. But the first gateway node is now about ready for deployment at sea.