Mithat Konar
A PCB implementation for sfrwmaker/soldering_907_lcd using a 1602 LCD.
Note: After starting this, I discovered that the supply of decent 907-style handles has really dried up. So I'm probably going to leave this unfinished and instead do what all the cool kids are doing and move to something using a T12-style handle.
I've tried to keep as close to sfrwmaker's original schematic as possible, but I made some changes to reflect best practices. In particular:
- I've added some additional 0.1u bypass capacitors.
- All the buzzers I looked at drew current that was uncomfortably close or exceeded the ATmega328p's absolute maximum of 40mA. So I adopted an easy to source (in the USA, anyway) buzzer (without internal oscillator) and added a driver circuit that offloads the Nano.
Some notes:
- Symbols that aren't found in the default KiCad 5.x distributions are in
local.lib. Footprints not found in the default KiCad 5.x distributions are inlocal.pretty. If KiCad barks at you about missing things, add these to the project using the respective symbol and footprint managers. - A custom Arduino Nano symbol was needed to make the design pass DRC. Specifically, the +5V power output pin was made a power input to reflect how that pin is being used here.
- Something better suited to the design than the inexpensive eBay LM2596 DC-DC module is very likely, but I used this because the original designer did so in their Hackster.io project. The footprint for this part is currently not correct. The outer dimensions were taken from an eBay posting, and the pad and mounting hole locations and sizes are wild guesses from images.
- Better alternatives to the MCP602 (and AD822) are probably available, but again I am sticking as much as possible to the original design.