NickelBot Updates
The NickelBot has been running great, but there were a few features I also wanted to add. I made a rev 2 PCB to address them.
Laser Door Interlock
There is a door switch that cuts power to the laser. I did this by splicing into the 12V power line going to the laser. I thought that was an effective, but ugly hack. There is now a dedicated connector for that switch.
Fan Control
On rev 1, the fans run continuously. This reduces my run time, when I run off a battery. I added a FET to control the fan power. I want the fans to turn on whenever the laser fires and stay on for a few seconds after the last pulse. Since the controller is a PSoC, I was able to implement this as a custom hardware peripheral. I used my pulse extender component.
Here is the schematic. The trigger is connected to the PWM signal going to the laser (labeled spindle). There is a 16 hz clock that is used to count down a short delay after the last pulse.
BlueTooth
Using a connected computer sort of spoils the coolness of these tiny machines. Using a phone and BlueTooth is way cooler.
Most of my other tiny CNC machines use BlueTooth. I don’t know why I forgot it this time. It is the first time using an HC-05/HC-06 bluetooth adapter with PSoC, so that might be the reason. I decided to use a second UART, so I could use both USB/Serial and Bluetooth at the same time. The changes to firmware where pretty trivial.
Grbl Controller Shout Out
The main Android phone app I use is Grbl Controller. It really works great and is so easy to use. It works great with the cheap HC-05/HC-06 BlueTooth adapters. I just send gcode files to my phone and run them from there. I can even turn the phone “off” and stream from my pocket.
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