If anyone is curious, turns out the SPI1 clock was shorted to ground through
the level shifter U?8 (pins 47 and 48 where shorted) beyond that, most of
the PCB looked a bit burned (discolored solder mask). Just a friendly note
to anyone with a similar experience, may really be a HW issue. After
reflowing U?8 with a hot air pencil, and cleaning up the short, the touch
screen came to life!
Now onto SW design challenges and other fun tasks.
On Tue, Dec 15, 2009 at 9:01 PM, Alex Stewart <kingsquirrel@...>wrote:
> I've probed all the relevant SPI signals found on the 40 pin header with
> an oscilloscope. They all look fine except SPI1_CLK never toggles. Is there
> some way to confirm the gpio mux settings are correct? This is using a stock
> flash image booting from NAND (the one the board shipped with) Also its an
> On Tue, Dec 15, 2009 at 6:15 PM, Alex Stewart <kingsquirrel@...>wrote:
>> Hi list,
>> Just connected up the 4.3" lcd, and set the uboot display to lcd43. System
>> boots fine and the lcd comes to life however the touchscreen does not.
>> Kernel log is reporting:
>> "ads7846 spi1.0: touchscreen, irq 274
>> ads7846 spi1.0: no device detected, test read result was 0x00000000"
>> Is there anything special that needs to be done in u-boot or the system to
>> enable the gpio to get the touch screen to work? or is setting the display
>> variable in uboot to lcd43 all that is needed?
>> Im new to this system and I'm trying to figure out if Im doing something
>> wrong in SW, or if my new board is simply bad.