This project use only four parts:
- Membrane Switch, a sample from spectra symbol they sent me 13 years ago.
- 5600 Omhs resistor salvaged from some device.
- AccessB from another project (7 years of slow development).
- Some pins and cable salvaged from some device.
My goal is emule a HID keyboard that send Windows + D key combination to minimize all windows and then istall it under my work desk so I can ocult procrastination when my boss suddenly arrive at my office.
Originally I thougth to use a 18F2550 PDIP that I have but I realise that I don't have the external crystal to make it work properly, so I reuse my AccessB hardware as a proof of concept, if this work then when the COVID-19 end I will make the definitive board that will be installed uder my work desk.
AccessB is 18F2550 based, so I use MPLAB X v5.30 under ubuntu 18.04.4 LTS with XC8 v1.32 compiler and MLA libraries v2017_03_06, the firmware is a modified version of the MLA project picdem_fs_usb.x to work with the 18F2550 and the externl crystal used with the AccessB, there are some other minors modifications only to send the Win+D combination every time the "key" is pressed.