Sometimes a project is just not meant to be. I picked up a Boogie Board LCD Writing Tablet when they went on sale to satiate my gadget addiction. I didn’t expect it to be hackable, as it is little more than a glorified chalkboard, but I figured I’d give it a try. My goal was to be able to lighten what was drawn on the screen, rather than erase it completely, to allow for the possibility of greyscale, or greenscale in this case.
I cracked it open (literally, I didn’t realize there were screws under the sticker), and found a more complex machine than I expected. The brains of the tablet are an MSP430F2001, one of the cheaper microcontrollers in TI’s MSP430 lineup. The header on the left hooks up to the programming pins, so anyone out there with a GoodFET might want to take a look at writing new firmware for it. Unfortunately, I didn’t have one.
The waveform below captured between the two big pads, TP1 and TP2, shows how the cholesteric LCD refreshes. On pressing the button, the power circuitry on the left generates 36v for 400ms, followed by 18v for 800ms, and feeds it to the multiplexer on the right. The MSP430 toggles the input pins on the mux to switch that input voltage back and forth between the two pads in 150ms pulses, flashing the screen green and black and clearing what was drawn on it.
Unfortunately, while lifting the PCB up to see the traces on the bottom, I snapped one of the connections to the LCD, rendering the tablet useless. Hopefully someone can pick up where I left off, modify the firmware on the MSP430, and see if its possible to make the LCD go only partway cleared by using shorter or fewer pulses.
Have you heard of any successful attempts to hack the boogie board?
Nope.
What type/model of battery is that?
Been there man. Sorry.
Probably a CR2032 with tabs on…
Would it be possible to save your writing and sketches, if some external memory could be attached?
It doesn’t have a touch screen. This type of display gets lighter when u push on it. It only uses electricity to clear it. No memory, no input. I would LOVE to see one of these screens hooked to a PIC micro TBH.
Does the battery look like it can easily be replaced
Is the cr2032 battery have the metal tabs solder to it? Or can u pop out the battery easily?
I believe those tabs were spot welded to the cell.
Just opened mine up, have a launchpad, so i’m going to see if the JTAG emulator on the launchpad will work with this chip. If it does, I will get the firmware and decompile, hopefully getting some info on how this thing works, since mine seems to have cut out the multiplexer for what looks like a few transistors.
I verified it works with bi-spy-wire. The pinout of the header is:
TDI TST RST GND
you can hook up the last 3 to a launchpad and run mspdebug. I’m working on getting the firmware off it (should be easy as mine is a MSP430G2111, with 1kb flash).
Just a thought… could we extract data from the internal antenna, run the signal to arduino, then bluetooth that to a tablet device or smartphone. Hence, we can utilize boogie board note taking feature and review our notes on our device more readily.