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Amethyst AUV Devlog | July 24-2019 | Arduino Mega Pro Mini as base controller

Amethyst Taxi - mini remote control of the craft is done. Mega Pro Mini in testing for Amethyst AUV. Small while same powerful as base Arduino Mega board could replace or modify previous concept of three separate Arduino Pro Mini controllers in Amethyst AUV.

As a first: Recap of May19 devlopment and testing:

1. Amethyst AUV Platform STL files were finaly published and are freely available under open source license.
2. Documentation page, basic components list are online. Files and docs are still in kind of BETA version, updating and upgrading will follow soon.
3. HC-12 radio module were incorporated in to AUV electronics and software concept and working stable. Test for range and stability in real environment is planed for this month.
4. Radio controller is ready in its BETA version. CAD files are done, PCB is done and working. Software is under constant revision but working.


Amethyst AUV Taxi box

Amethyst AUV Taxi electronic


What is in development now:


1. Arduino Mega Pro MINI

This board was picked as main controller for motors, servos and sensors. It maintain Raspberry to Arduino concept of communication via I2C bus, but most of sensors are now allocated in to one board together with motors and servos compare to previous concept of three separate controllers. Custom PCB were introduced for simple connections of accessories with board. This way more space was saved inside dry compartment and wiring is bit less messy.

Arduino Mega Pro mini

2. PCB for Raspberry I2C bus was introduced

Together with Arduino Mega Pro Mini PCB the Raspberry Pi Zero I2C/Serial interface PCB came into ecosystem of Amethyst´s electronics. Beside the fact it looks pretty, we got  way more reliable solution of interfacing Raspberry.

Amethyst AUV Raspberry Pi ZERO I2C / Serial board

3. Radio communication and telemetry

Software tweaking of radio communication is constant job. With growing amount of data to be transmited each way there is version fork which should change basic concept of transmiting each piece of data and each command separately to sending and receiving both telemetry and comands in arrays - packages.


4. Autonomy

Basic - ALFA concept of autonomy software frame was lay down. System will be based on digital compass, GPS reference poinst - fix (on surface) and speed vs time formula - dead rocogning. First step is to know some AUV´s specifications.

1. When rudder is turned in Y degrees and speed of craft is X in which arc will AUV turn and how it will look from the GPS point of view.

2. Detemine the speed of AUV versus RPMs of brushless motor on surface and under water.


5. 3D printing for underwater applications

Knowledge base focusing on 3D prointing of water tight object was started. In the article I will collect all information about this topic. You can check it here


Near future:

1. Maneuverability, speed, endurance field test

2. Radio connection - range, stability field test

3. Dynamic diving procedure using vertical thrusters field test

4. Amethyst software upload


Thank you for support and whatever possible thougts and ideas. You can reach for me any time soon via anty()