Proxmark3 community

d18c7db

Contributor

Registered: 2008-08-19

Posts: 292

Proxmark with color LCD

Success! I ended up connecting a Nokia color LCD to the proxmark and displaying some stuff on it. In the picture below I attached the LCD to the top of FPGA with double sided tape and then also attached the ribbon to the top of the ARM with double sided tape also. I removed the tiny connector from the ribbon cable and soldered directly to the pads. Initially I tried to use green wire (wirewrap) but it turned out to be too stiff and bulky so I ended up using the thinnest wire I had, 0.125mm enamel coil wire.

The LCD is a bit hard to see as the backlight is off and the screen protector has not been peeled off. Initially I was hoping the LCD backlight was LED based and I'd be able to run it off the board's 5V supply, however in practice the 5V isn't enough to light up the backlight. Not even a little. You need a minimum 6.5v and ideally somewhere between 7V-9V so at this stage the backlight will stay off. This is why the LCD colors in the picture appear dim and washed out. I'd need a DC/DC boost converter to power up the LCD backlight off the board supply.

The LCD connects to the Serial Peripheral Interface, SPI bus (SPCK, MOSI) which normally goes to the FPGA. JW originally coded the comms to the FPGA by bitbanging so I ended up changing the code to use the SPI to both the FPGA and the LCD. The FPGA is selected with NCS (PA11) and the LCD is selected by an additional spare pin NCS2 (PA10). In addition to that one more pin is required PA7 as the LCD reset line. Closeup of the final hookup can be seen below.

To complicate thinks a little these, LCD's come in two flavours, Phillips PCF8833 and Epson S1D15G10D08BE based controllers and the LCD commands between them are different and, get this, the Epson LCD doesn't support serial output so you can't query the LCD to find out which type you have. Grrr... Anyway I bought a lot of 5 Phillips LCDs off ebay for $9.95 free shipping (ex Hong Kong). I don't need 5, but the price was right and I'd rather have spares in case I stuff one up. Or use some for other projects.

Originally I tried to use some ARM LCD driver code off the sparkfun.com web site that was supposedly written for the Phillips LCD controller but it didn't seem to work. Turns out the LCD commands matched that of the Epson controller even though the source files were called PCF8833U8_LCD.c  Weird. The guy who wrote the code said he based it on the Phillips datasheet !?!? Confusion reigns

Anyway this is a proof of concept experiment. If ever a proxmark4 is designed I believe this 130x130 pixel color LCD a good fit as it's easy to interface (only 4 control lines), cheap, ubiquitous (milions of Nokia phones), runs off 3.3v and a one chip boost converter for the LCD backlight could easily be implemented on board to supply the 7v required. The LCD can support 16 lines of 21 characters with a 6x8 pixel font.

Last edited by d18c7db (2008-12-11 00:03:32)

brokentesting

Member

Registered: 2008-11-22

Posts: 13

Re: Proxmark with color LCD

d18c7db,

This is EXCELLENT!!!!

n0t

Contributor

Registered: 2008-11-24

Posts: 26

Re: Proxmark with color LCD

Nice pimpin' work!

d18c7db

Contributor

Registered: 2008-08-19

Posts: 292

Re: Proxmark with color LCD

I ended up hacking the LCD to not require 7V LCD backlight by opening it up and wiring the two white LED in parallel instead of in series. The backlight is now powered by the 3.3V rail.
Wouldn't recommend doing this hack though, it's a bit of a pain.

Last edited by d18c7db (2009-01-15 02:18:06)

samy

Contributor

From: los angeles, california

Registered: 2009-06-18

Posts: 148

Website

Re: Proxmark with color LCD

d18, I'd like to get an LCD as well.

Should I get the Philips PCF8833?

d18c7db

Contributor

Registered: 2008-08-19

Posts: 292

Re: Proxmark with color LCD

Well the problem is you never know what chipset LCD you're gonna get. You could buy one off sparkfun I guess. I managed to get a 5 pack off eBay ex hong kong for $10 free shipping so check there as well. Regardless of what you end up with it doesn't matter as we can program either. I have the relevant datasheets.