Components ordered, firmware development

A project log for ElbSupply - Simple linear bench supply

This project aims at building a rather simple yet useful bench power supply for everyday tinkering.

EliaElia 03/15/2015 at 16:270 Comments

I have ordered all the other necessary components so I can assemble the board as soon as the PCBs arrive from OSHpark. After I had sent the PCBs off to OSHpark I had noticed that I had forgotten to put in the LM334 constant current sink but I quickly added that to the layout and contacted laen to change the gerbers, hence the rendering that you can currently see in the gallery for this project aren't completely correct as they're missing a chip.

The LM334 is needed because for stable operation the LT3083 needs a minimum load current of 1mA.

The firmware development has also progressed pretty far. The complete user interface and control code is implemented as a finite state machine. I am not sure whether I will employ software debouncing of the buttons too or if I rather just rely on the hardware debouncing circuitry I have added. The only thing missing from the control code now is just reading the button and encoder pin values and changing states in the state machine accordingly.