StarTAC SED1530 LCD and Keypad hardware, Telit GC864 cellular

Finally an update! Gotta slip one in before the end of June, so it’s not been a year between posts.

Lots has happened since I last posted including a burglary at our rented town house which triggered us to look for another place to live. We ended up buying a house (!) and moving. Finally finally this month I have had a chance to organise my workspace and unpack some of my microchips.

Last night I transplanted the male socket that connects the StarTAC’s keypad / LCD board to the mainboard over to a breakout board so I can begin trying to control the LCD myself by interfacing to the SED1530 controller chip. Ideally I could use the 2-wire SPI interface the chip has, but it is possible that Motorola used the parallel interface and hardwired it such.

Removing the socket from the StarTAC mainboard was relatively easy – the pins are not completely flat against the board so I was able to get one side of some tweezers up and underneath them and gently pry them off the board. In the image below you can see some of the traces came off with the pins, but that’s fine.

A while ago when wondering how I was going to be able to prototype the LCD, I realised that the pitch on the socket pins was 0.5mm – the same as the socket pitch for the Telit GC864 cellular module which I failed to post about and will mention further down. I bought a SchmartBoard|ez SOIC .5mm Pitch breakout board from Curious Inventor which as you can see in the picture will give me easy access to the LCD / keypad pins.

Many moons ago in a previous post I declared that I was going to use the Telit GE863 cellular module for this project. My primary reason was that it was the only module Telit offered that was small enough to physically fit inside the StarTAC housing. The big problem with that module is that it’s pins are BGA – very hard for a hobbyist of my level to use and offers minimal flexibility in terms of avoiding screwups.

When I found the cash and the will, Telit had released several new modules including the GC864 which uses a nice 80-pin connector, with a separate antenna socket! Perfect all-round for hobby prototyping. I bought it, two circuit-board-antennas with the right type of connector plug and two mating 80-pin connectors.

Before the burglary last autumn, I was hard at work for a few weeks hooking up and testing the GC864. I found and bought the same SchmartBoard 0.5mm pitch breakout board linked above and soldered one of my connectors to it to get access to the GC864′s pins. With a lot of jumper wiring and a few hacks to compensate for my lack of female-to-female jumpers I got it working, controlled by serial over USB to my desktop PC. This mess was the result:

Power was supplied by a StarTAC battery pack which is in bad condition and required constant charging to be useful. Still! I managed to send myself an SMS message and place and receive phonecalls, though I did not have a speaker or microphone connected so they were quite calls.