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There is two RPi in this project. One is in the suitcase, and one in the ROV.

Password ROV: send email: williha@stud.ntnu.no

ROV

Model: Raspberry Pi 4B rev 1.4 4GB

Suitcase

Model: Raspberry Pi 3B+ 

Docs

Raspberry pi 4

Raspberry pi 3B+ (default password)

Fathom-X Tether Interface rev2

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FathomX is an Ethernet bridge between the ROV and the suitcase. This enables communication through the tether cable.
The FathomX is connected to each side of the tether. It requires only two wires for communication. 

Reference

Blue Robotics Guide and DocsWebsite and documentation

SwitchBlox Nano

This is a miniature ethernet switch.
It is used inside the ROV for communication between different ethernet devices. (RPi, Fathom-X, and external sensorSide-scan sonar)

Reference

botblock.io Guide and DocsWebsite

Teensy 4.0

Two teesny 4.0 is used in the ROV. One Both are connected to RPi with USB.
Teensy is used instead of Arduino because it has a faster processor.

Teensy for stepper control

This teensy is for controlling the both stepper motors drivers. (wings)
Stepper Teensy is running this code.
The other NOTE. update link after merge

Teensy for sensors

This teensy is gathering data from various sensors .
Both are connected to RPi with USB.

Teensy is used instead of Arduino because it is faster.

Guide and Docs

Getting started guide

and sending data to RPi.
Sensor Teensy is running this code.  NOTE. update link after merge
Sensors connected:
 - Echo sounder
 - Pressure sensor
 - Leak sensor
 - IMU

Reference

Getting started guide

Teensy 4.0 Documentation

Leak Sensor

Image AddedImage Added

Leak sensor detects water leak in the electronics tube.

Reference

Blue Robotics Guide and Docs - Chip

Blue Robotics water probe

IMU

Image Added

Inertial measurement unit is gathering positional data of roll, yaw and pitch.
Is connected to Seensor Teensy with 3.3V i2c.

Model: Adafuit 9-DOF BNO055

Reference

Adafruit IMU docs

Depth Sensor 

Image Added

Depth sensor is measuring pressure. It is used to calculate the depth of the ROV. (Length from water surface to ROV)
It communicates with Sensor Teensy with I2C.
The sensor also has built in temperature sensor.

NOTE: Sensor looses accuracy if its wet for more than a day.

Model: Bar30 High-Resolution 300m Depth/Pressure Sensor

Reference

Blue Robotics Depth Sensor Guide and Docs

I2C Level Converter

For i2c devices with different voltages. 

Not used. Old system used arduino with 5V I2C logic. Teensy used 3.3V logic.
All i2c sensor in ROV uses 3.3V.

Reference

https://bluerobotics.com/store/comm-control-power/tether-interface/level-converter-r1/Teensy 4.0 Documentation

Stepper Motor

Stepper motors controls the two wings on the ROV. It has a gearbox to increase torque. 

Model number: 17hs19-1684s-pg100

Electrical Connection

Electrical Drawing -> Stepper Diagram

Datasheet

Torque Curve

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A stepper driver is used to control a stepper motor. Teensy is controlling the Driver.
There is one driver for each stepper motors. (2 in total)

VREF is configured to 0.8V which corresponds to 1A/stepper phase.

Electrical Connection

Electrical Drawing -> Stepper Diagram

Reference

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Pololu Guide and docs