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Steve Markgraf steve at steve-m.deHi, On 28.07.2013 09:20, ubuntugirl wrote: > Were you ever able to figure out just how the backlight works on this > display? Your code has a comment about a particular register in the > SPCA supposedly turning the BL on or off, but looking at the pin > interfaces of this SPCA in the Nokia schematic, I don't see anything > even remotely related to the backlight... Yet the original firmware is > able to not only turn this BL on and off at will, but also change the > brightness - during calls, the display dims instead of blanking > completely. Yes, and it took me a while. The basic 'on/off' is controlled by the SPCA with the code we have, the brightness is controlled by the PWL-unit of the Calypso, but inverted if I remember correctly. Just play with the bl_level() function a bit. > On a related note, were you ever able to figure out the pinout of the > 30-pin flex between the main PCB and the LCM? If this pinout were > known, I could probably trace out the stuff of interest to me (like > the backlight) on the main PCB using your layer pictures, but if I > have to reverse-eng the LCM itself, that might be a bit above my skill > level. :( At one point I soldered wires to all connections and hooked them up to a logic analyzer. It's a 16-bit interface and it was quite easy to figure out what was what. For all the initialization only 8 bits are used, for the actual display content you switch to the 16-bit mode. > Bummer. But just out of curiosity, how did you figure out that it's an > 8051? Did you see the original phone fw pushing something to the SPCA > that looked like 8051 instructions? > FWIW, the 554 datasheet describes its CPU as a "32-bit RISC processor" > - too closed to even name what it is! Now that I see the "32-bit RISC processor"-comment as well... no idea where I got that from, it's most likely wrong then. I didn't look at the instructions, but as far as I remember I've seen a code blob being uploaded. Regards, Steve