I recently received a few TI LaunchPads that were in immediate need of a project. I have decided to dedicate one LauncPad for use in a scoreboard project I am calling the bacBoard. I'll document my progress here for those interested in exploring different applications based on the $4.30 TI LaunchPad.
I need a game plan for how the score board is going to look. [flickr-photo:id=5294575647,size=-,style=margin:10px]
First we start things up with a Blinky:
Next I need to come up with an offensive strategy for how the score board is going to get built.
Since my scoreboard will have eight 7-segment displays it will require 56 (8*7) IO pins that the LaunchPad (MSP430G2231) obviously doesn't have. Luckily NXP has come to the rescue and developed an I2C based driver (SAA1064) that can handle up to four 7-segment displays per IC. First lets wire up the the SAA1064 driver and see if we can communicate to it via I2C and simply toggle some LEDs. Did I hear someone ask for another Blinky?
Next lets wire up two seven segment displays and make it countdown.
So what is next? Quite a bit. Come back and watch the bacBoard build unfold.
Assemble 7-segment displays to PCB. Use 0.100" headers and IDE cables to connect the multiple boards.
TODO 1 - COMPLETE!
I am using the SAA1064 in static mode which only allows for two 7-segment displays. The SAA1064 will support four 7-segment displays in dynamic mode which will require two NPN transistors. I found two 2SD05920RA NPN transistor in my junk box. To ensure I was in dynamic mode I measured the ramped waveform that can be found on Cext (pin 2). After some modifications to the firmware I am now able to use four 7-segment displays.
The LED 7 segment displays will need a boost supply so that the bacBoard can run off of a Lithium Polymer battery.
I will want to charge the bacBoard so I will need a Lithium Polymer battery charger.
Add two switches (arcade buttons) as user input.
Integrate all the components in the enclosure.
Print the bacBoard template.
Re-factor FW so that I am not too embarrassed to publish.
Move on to the next project. :)