It was time to package my NodeMCU signal generator experiments into a finished product. Breadboard prototyping proved the concept. The software was written and working.
The first step in packaging the NodeMCU signal generator is a printed circuit board. A PCB simplifies mounting most of the parts and wiring them together. In my case, the wireless microcontroller and direct digital synthesize module fit onto the PCB. A few discrete components (capacitors, resistor) are also mounted. The PCB will then go into a plastic case.
The LCD readout and rotary encoder will mount on the project box lid. Short jumper wires will connect these to the PCB. Lastly, terminal blocks are available for connecting to a 5 volt power plug, and for running the signal output to a BNC connector. Both of these will sit on the back panel.
Rather than soldering the complex computer and DDS modules to the PCB, I mounted them on headers. This also makes it easy to remove these parts at a later time.
NodeMCU Signal Generator – Designing the Case
Now it is time to build the case. Having all of the parts laid out as shown above makes it easier to design a 3D printer model. I can take measurements and make sure everything will fit once the box and lid are printed. The box will have a separate lid for mounting display and local control. I know from the sizes that this box will be a “big print”. Consequently, I want to make a really good design so it will work the first time.
As a final note, I think my supply of copper boards is nearing the end of its useful life. The copper layer is wearing away and I often have to do some repairs to incomplete traces. It’s hard to believe, but I am still using up a supply of copper board stock that I purchased forty years ago! Like they say, never throw anything away. It might come in handy one day.