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Posts Tagged ‘bb5’

Time to post some details

September 12, 2010 2 comments

Here you have interface schematic & pcb i’m using to prototyping :

Schematic:
sch_e51
PCB:
pcb_e51_lcd2

Schematic is totally based on BikeRk6’s one, posted here : http://www.elektroda.pl/rtvforum/topic1344700.html

PIC32 Code – Nokia E51 Library:
LCD_E51.ZIP
PIC32 Code – test workspace
test_e51lcd.zip’

Consider this code as pre-alpha release 🙂 It’s dirty, it’s uncommented. It works only partially -> depending on your LCD… You may find it similar to Microchip’s graphics library… it isn’t totally unintended 🙂

Have fun, feel free to improve it!

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Categories: LCD, microcontrollers Tags: , , , , ,

Using Tearing Line Output from Nokia LCD

September 12, 2010 Leave a comment

Nokia LCDs mentioned in this blog has tearing line output feature. It can be used to synchronize MCU->LCD writes with LCD display memory scan pointer.
What for? To prevent showing partially content we want to write to LCD’s display RAM.

Problems :
A) your MCU should be fast enough to stream whole framebuffer to LCD within TE (Tearing Effect line output) pulse -> then, LCD read pointer won’t start scanning the frame before whole MCU->LCD transfer ends.
OR:
B) your MCU should be fast enough to stream whole framebuffer to LCD between n and n+2 TE pulses -> then LCD read pointer starts before write to LCD display memory occurs and write pointer will be always behind read pointer of LCD’s memory controller.

If your MCU isn’t fast enough to meet these requirements, tearing would always appear…

TE pulse width is given by LCD’s frame refresh rate (default ~60Hz).
At 60Hz frame scan time is about 16ms. Full frame is 320x240x3 bytes = 230400 bytes. To be able to write full framebuffer during two frame scan time (option B) your MCU should have data computation & throughput speed ~7 MB/s…
Well, it is impressive in the world of cheap and easy MCUs, even PIC32s 🙂

Categories: LCD, microcontrollers, PIC32 Tags: , , , , , ,

Using Nokia BB5 LCD with PIC32

September 11, 2010 Leave a comment

Short brief :
source : http://www.elektroda.pl/rtvforum/topic1344700.html
help :
– Leadis reference to LDS285 : http://www.trulydisplays.com/tft/driveric/IC%20Spec%20LDS285.pdf
– Microchip toolz & CPUs
objective : using Nokia’s LCD with Microchips CPUs

Finally, objective achieved 🙂

Findings :
“Modern” BB5 Nokias are using MIPI’s MeSSI bus between MPU and LCD controller.
Although obtaining MeSSI specification from MIPI can be hard for hobbyist, bus is 100% compatible with popular 8080 Interface = Mode2 Parralel Master Port in PIC32… 🙂
LCDs of E51 or E65 are pin-to-pin compatible, many others (BB5-style) has the same pinout and connector.

Pros:
– 320x240x24bit LCDs
– integrated controller with DDRAM (no need to waste MPU RAM for storing display data)
– cheap solution (~8-10$ for a piece of glass)
– simple interface, really 🙂

Cons:
– such LCD require relatively high computational power

more info incoming soon…