Hi,
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