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