I have been an embedded programmer for decades, but only in large projects, and it might surprise you that most of the software guys never learn anything about hardware.
I prefer the Onion Omega 2 to the Raspberry Pi and would like to code a project which requires a 4x4 keypad, while at the same time using their display Hat shield thingy
The pin out for the GPIO is at https://docs.onion.io/omega2-docs/using-gpios.html
The forum post at http://community.onion.io/topic/1507/how-to-use-oled-with-gpio/7 says that
"The OLED uses I2C, so (as far as I am aware) the only pins you should need to connect are:
I2C SDA
I2C SCL
GND
3.3V"
So, the rest would be free for the keypad. That post also recommends using their $5 proto expansion board (Sorry, the link is in acomment following this post, as new users are limited to 2 links)
Questions:
- which cheap 4x4 keypad can I use for a proof of concept?
- how would I wire it?
- can I do it without soldering?
Sorry to ask what is probably a very basic “hello world” type question, but that’s about the limit of my hardware ability :-)
Many thanks in advance for any help.