Week Review 12/7/2023

Depth Sensor

For the MATE ROV 2024 competition we need the float to be able to accurately measure the depth of the float. Thankfully Blue Robotics makes a sealed depth sensor that can be mounted similarly to a Wetlink Penetrator.

Connecting to Adafruit QT PY

I am using polarized connectors to connect the depth sensor to the board. I crimped them so I can switch from the Adafruit QT JST connectors to other connectors.

Once I had the wired connected I tried to use the MS5837 library to interface with the depth sensor and it was failing to initialize. I checked the probe points on the crimp connector to see if power was being sent.

There was power being sent, I and I suspect that the issue is the many I2C ports on the Adafruit QT Py. I switched to using the Adafruit Metro Mini instead because there was only one I2C connection on it.

The goal of this switch was to isolate the problem to the depth sensor, if the problem was with the depth sensor.

Connecting to Metro Mini

I made a new connection to the using another polarized connector so that I could connect to the I2C pins on the metro mini. When I used the library again, it was able to get past initialization and I got output from it. Unfortunately the output was not very rational.

Bad Data From Depth Sensor

The data I was getting from the depth sensor was not possible. The temperature reading I am getting is an order of magnitude below absolute zero. I am fairily certain it is warmer than that in the room so the temperature is off.

Pressure: 4032.86 mbar
Temperature: -2191.77 deg C
Depth: 30.89 m
Altitude: -13319.82 m above mean sea level
Pressure: 4032.86 mbar
Temperature: -2191.77 deg C
Depth: 30.89 m
Altitude: -13319.82 m above mean sea level
Pressure: 4032.86 mbar
Temperature: -2191.77 deg C
Depth: 30.89 m

Following the guides on their website I made sure I am using the right depth sensor. After looking for answers online I found a few forum threads were people were having similar issues, and the culprit was a faulty sensor.

I wrote an email to BlueRobotics support. They have not gotten back to me yet, but I am hoping that they either help me find an issue with my setup or send me a replacement.

Holiday Decorations

Since it is now December my row and I quickly made some holiday decorations to make our row a more fun space. We have cardboard candy canes, cardboard trees, Christmas lights, and “chestnuts roasting on an open fire”.