Uncut Gem

PCB

This folder contains the entire KiCad project for the diamond sensor, with full electronics. The Git History contains previous versions, including the version first presented at BSides London in Dec 2024!

The schematic may be found here.

Here are two renders of the first version of the board:

Bill of Materials

Here is a bill of materials for the various parts and connections on the board:

NB - Here are some notes about this design:

1. Capacitors C5-10 are optional, mostly included to deal with unsteady USB power supplies.
2. Capacitors C1 and C2 turn the transimpedence amplifier into integrator mode. If they are omitted, it will operate as a regular inverting OpAmp.

Additional COTS Parts

There are several additional parts that are needed for this pariticular version, detailed below.

ADF4351 Dev Board

The specific board used is this part on AliExpress. The key part is to expose the SPI pins (DAT, CLK, CE) as well as the power/ground and LE (Load Enable) pin.

40db Gain RF Amplifier for 30-4000MHz

Specifically this part on Aliexpress. This just requires power and ground, which are routed to the 5V power and ground connector.

Green Laser Module

We used a module we acquired off Amazon UK (no longer available), but in reality any laser module may be used, as long as it uses provides the following:

• 520nm - 532nm green light
• a laser point of light
• is around 10mm wide by 22mm long.

ESP32 Dev Board

We use one that is 2x rows of 19 pins with the pin-out described in the schematic. You can use 15-pin boards, but you'll have to add wires for power and ground manually.

1.3" OLED Screen

These are standard OLED boards using SH110X-based screens driven by I2C (not SPI). BEWARE - many of the screens swap VDD and GND. This design uses a board with pins in order (as you look at the screen): VDD/GND/SCK/SDA

If your screen has GND/VDD/SCK/SDA, then you need to do some work on the PCB to fix it, or acquire a different screen.

Cost per Device

The ballpark costs are as follows (in GBP):