Motorola 4500x rebuild with arduino + sim900

[robvanderveer]

I would like to share my project. A few years ago i bought a very cheap motorola transportable phone from the 90’s. The electronics inside are worthless because the radio towers no longer support the system. It weights 3.5kg mostly because of the massive 3800mAh battery.

I am currently replacing the entire innards of the phone, the only thing you notice on the outside is the use of a 132x32 lcd screen instead of the original 10-digit bulb 7-segment display.

So heres what i needed to do:
- make a pcb that fits the handset
- atmega 328p minimal arduino with ISP port
- interface with EFCom sim900 module
- minimal wiring between handset and old transceiver module
- latching soft-power switch for 12v charger to 5v logic
- 5v to 3v3 conversion for display
- reverse engineer keypad

[robvanderveer]

Here's what it looks like now:

[robvanderveer]

Hip hip hurray. Got the display prototype working, fonts stored in PROGMEM and much more. Things are really coming together now.



I need more icons!