Components List as of 30 May 2023

A project log for "Mercator Origins": Sat Nav & Telemetry for Divers

Want to map your dive? Want to navigate like a pro? Even if you are vision-impaired, this will empower you to navigate our underwater world.

mark-b-jonesMark B Jones 05/30/2023 at 11:050 Comments

I wanted the components list as of today to be listed out in a categorised order. The components project section unfortunately is flat, so hopefully this will present the information in a clearer manner.

Mechanical Components for the Mercator Origins Sat Nav/Telemetry Console

Yellow Float box with transparent lid - Underwater Kinetics IP67 Ultrabox 408 (waterproof to 5m), including lanyard. 
1 x yellow cable/hose strain relief rubber tube (beaver with amalgamating tape or unbranded)
1 x Nite-Ize S-Biner size #4 or #5 - black or stainless steel
11 metres x 4-core 4mm sub-sea Blue Robotics Ping Cable SKU: BR-100452
2 x  Blue Robotics 4.5mm LC Wet Penetrators SKU: WLP-M06-4.5MM-LC-R1-RP (6mm drill bit required, recommend stepped drill for drilling housing, HSS drill for float box)
2 x 6mm non-shake washers
Navigation Console: 1 x gopro hero 9/10/11 housing - non-OEM or OEM
Audio Module: 1 x gopro hero 9/10/11 housing - non-OEM or OEM
1 x upcycled generic 3D Print spool (diameter: x cm, depth y cm)
2 x button mounts - 3d print and schematics
2mm nano/gecko tape - fix housing to spool
1mm nano/gecko tape - mount internal components

Float Electronic Components

1 x USB Power bank - minimum 2500 mAh

1 x Wifi Hotspot - either a mobile phone or a MiFi-type WiFi hotspot (eg by TP-Link)

1 x USB A cable.
1 x USB C plug - breakout with solder pads
1 x 4-way Micro JST male and female connectors/wire
2 x 2-way Micro JST male and female connectors/wire

Clear plastic enclosure box (M5 Stick C Plus Watch box)

Float computer: M5 Stick C Plus ESP32 microcontroller
1 x M5Stack MiniGPS/BDS unit AT6558 (Serial UART comms)
1 x 1 Amp fuse holder and fuse
1 x RS485 module (5V power, 3.3V signal) (generic board based around MAX485 IC)
1 x Grove connector female to female 4-core cable - GPS unit to M5 Grove connector
Silicone wires (multiple colours)
Future version: 2 x relays and reed switches for contactless rebooting of float and entire system using magnet waved by user over 2 marked locations on the float box.

GoPro Navigation Housing Electronic Components

Guidance Computer: 1 x M5 Stick C Plus ESP32 Microcontroller
Dive Timer Computer: 1 x M5 Stick C Plus ESP32 Microcontroller

Mechanical push to make switches: 2 x car remote control switches maximum thickness: 2mm
Non-contact inputs: 2 x potted reed switches
Leak Detector: 3 x 1M Ohm 0.25w Resistors and 30cm solid core bell wire
IR interface: 1 x ? Resistor and 1 x ? Phototransistor

Generic RS485 module (5V power, 3.3V signal) (based on MAX485 IC)
Adafruit LSM303AGR Accelerometer / Magnetometer - Digital Compass
Adafruit BME280 Environmental Sensor: Temperature, Relative Humidity and Air pressure sensor:
Blue Robotics MS5837 Depth Sensor 300 metres max depth
Future version: Adafruit APDS9960 Proximity, Light, RGB and Gesture Sensor

Silicone wires (multiple colours)

Connectors for navigation housing

2 x 8-way 90 degree PCB header
2 x 8-way Micro JST male/female connectors
4 x 2-way Micro JST male/female connectors
3 x 4-way Micro JST male/female connectors
3 x Stemma QT/Qwiic 4-way female to female cable connector
1 x Grove to Stemma QT/Qwiic female to female cable connector

Audio Module Electronics

DFRobot Beetle ESP32-C3 (RISC-V Core) Microcontroller
3.6V 18650 lithium rechargeable battery and holder
Adafruit micro SD card breakout board
8GB SDHC Micro SD card
DFRobot MAX98357 I2S Amplifier module - mono 3W
Dayton Audio DAE13CT-4 4 ohm/3W coin type 13mm exciter (surface sound transducer)

future plan: Adafruit BH1750 Light Sensor
future plan: solid state fuse
future plan: 2 x potted reed switches
future plan: : Adafruit VL53L4CX Time of Flight Sensor 1mm to 6000mm

Audio Module Connectors

1 x 4 way Micro JST connector male
2 x 4 way Micro JST connector female
1 x USB C plug - breakout with solder pads
Silicone wires (multiple colours)


2mm and 1mm thickness nano tape

dual wall heat shrink - sizes: 1mm,2mm,4mm,6mm
The rubber white putty stuff?
Hook and Loop fastenings
Red, Black, White, Yellow, Blue, Green silicone wire 30AWG or 24AWG?
Glue gun stick


Glue gun and cordless drill
6mm HSS drill bit for cable connector at float box. ( or step drill)
Stepped drill for 6mm hole for cable connector of gopro housing and 10mm hole for depth sensor.
Temperature controlled soldering iron at 360 degrees C
Tin solder, tinning compound, flux, wound wire tip cleaner
wire cutters and wire strippers for 30AWG wire
6mm ? spanner/wrench - wet penetrators
12mm ? spanner/wrench - depth sensor
multimeter - continuity and voltage checks

Pressure Pot for pressure testing the Mercator Origins diver's console and audio module

I have modified slightly the design of the pressure pot documented by Michael Macdonald (macado) to suit the purposes of my project:

Pentek Water Filter Housing 3G100SCCF 3/4" Ports - max 8.75 bar / 125 PSI pressure

Pressure Gauge to 7 bar / 100 PSI with 1/4" NPT bottom mount

1/4" NPT Male ASME Brass Safety Pressure Relief POP off Valve 80 PSI

OTG Scuba Diving 1/4" NPT Male to Standard BC Inflator Schrader valve connector adapter

T-Connector Female/Female/Female 1/4" NPT Brass Fitting

T-Connetor Male/Female/Male 1/4" NPT Brass Fitting

Hex head 1/4" NPT Male thread connector coupling adapter

Brass Inline Mini Ball Valve cut-off switch, 1/4" NPT Female, rated to 600 WOG

Brass hex bushing reducer - 3/4" NPT Male x 1/4" NPT Female

Brass 1/4" NPT male thread connector coupling - end stop