The Sparkfun LCD is OK – but, it seems really old (surplus). So, I went looking for something new (but similar). Ultimately, I found something interesting at Mouser from a company called Electronic Assembly. Seems they have taken a COG (chip on glass) display and fused PCB legs onto it. The price also helped – only $12 bucks. The displays are monochrome and have a graphic format of 102×64 pixels. The displays are designed to interface to a micro using a SPI bus. Note, these version of displays that use a SPI interface are read only. The display has no MISO pin to allow the display to be read. The Sparkfun / Nokia 5110 display was the same – no MISO pin.
Just five wires (plus power & ground) is all it takes to interface one of these displays to the STM32 Discovery board. Oh, and three 1uF caps are required too.
Mouser has three of these LCD listed on their site. The Mouser part numbers are: 790-EADOGS102W-6, 790-EADOGS102N-6, and 790-EADOGS102B-6. The last letter in the part number designates the LED back-light to use. Another note, the display does not have its own LED back-light. You must provide your own or but their accessory LED back-light. Anyway, the EADOGS102W is designed for a white LED back-light and the EADOGS102B is designed for a blue LED. The EADOGS102N does not use a back-light – it uses natural ambient light – there is a silver coating on the back of the display.
Blue EA Display
This is the EADOGS102B display right out of the packing material. I’ve also removed the protective film from both front and back. It’s cool, you can see the LCD state machine chip embedded right on the glass. The pins along the top edge are for LED back-lighting (according to the datasheet). I applied some voltage without anything lighting up. I’m not sure why the claim they are for back-lighting. Seems more likely that the top edge pins are simply for mechanical mounting.
The attached source code is the same old FreeRTOS project again. However, it’s been slightly modified to drive the EA display instead of the Nokia 5110 display. There is a single #define in lcd.h that defines “EA_LCD” instead of “NOKIA_5110″. Simply search the source code for EA_LCD to see all the places where the source was changed. You can switch back to the Nokia display simply by swapping the #defines around.
Download Source: Copper Source Code for EA Display
