1. Preparing for Assembly

Before assembling we will test each board progressively to make it easier to troubleshoot issues.

The Arduino Pro Mini requires a USB serial board in order to be programmed by your PC. This enables the board to be smaller in size as it doesn't have a serial interface on it. To programme these boards you will need to invest in getting one as outlined in the part list.

Before loading the Arduino code you will need to add the Library "FastLED.h" as a library to drive the WS2182 LEDs.

A series of Oscilloscope Traces have been provided for troubleshooting if there are issues.

There is also a screenshot of the IDE serial data output using the Graph Plot function which shows the pulse width output of each of the channels as well as the threshold value. This is useful during testing as you can see if each channel is performing to similar levels of sensitivity.

I have included two copies of the code. One has test serial data streaming for troubleshooting purposes.

NOTE: Do not connect the LiPo Battery unit until the very last step as accidentally shorting this out during assembly can cause the unit to overheat or even catch fire.

2. Test the Main Board

Before connecting the main board to anything it is advisable to attach the Arduino Serial Cable and verify that the code loads.

This will simply test that you have the Arduino is physically wired correctly and that the IDE and libraries are loaded. Load the code through the IDE which should load with no errors and no smoke should come out of any components!!

3. Connect the Driver Board

Follow the circuit diagram to connect the Driver Board to the Main Board and physically position the unit in the case to ensure items fit within the enclosure. This is a case of trial and error and requires persistence.

Load the code through the IDE which should load with no errors and no smoke should come out of any components!!

4. Connect the Coils

Follow the circuit diagram to connect the Coils to the Main Board and physically position the unit in the case to ensure items fit appropriately. Carefully ensure the coils are aligned with the Driver Board and Main Board inputs as per the circuit diagram.

With the test code loaded the serial port will display the pulse width on the receive coil somewhere between 5000 - 7000uS. This can also be viewed using the IDE Graph Plotter.

This will enable you to troubleshoot each of the channels and also see the effect of moving a coin near the search coil which should reduce the pulse width as the target gets closer to the search coil.

If you have an oscilloscope you can also check the waveforms at various stages of the circuit to diagnose issues.

Once all channels are performing as per expected position the wires so that the case enclosure will assemble and close correctly.

5. Connect the LEDs

Carefully take the three wires from the Coil Enclosure LEDs and connect them to the main board. Load the code and verify the LEDs are operating correctly. Use glue to fasten the coil enclosure lid into place.