On Thu, Aug 27, 2009 at 3:31 AM, Adam Wang <adam@qi-hardware.com> wrote:
Hi Carlos,

It does not work for me.

I tried to:
place a 330 Ohm between KEYIN3 and GND, connect BOOT_SEL1(should be SEL1 to select USB boot) to KEYOUT7, also have a pull-up R5 10K.
I found KEYOUT1~7 are normal low; when push "U" key, the KEYOUT7 will have a pulse with 50us high to scan during NAND boot mode.
the KEYIN1~7 are normal high; when push "U" key, the KEYIN3 measurement is the same as KEYOUT7.

In this case the processor enter to USB mode?
 

but if place 330 Ohm between KEYIN3 and GND, will get a very low voltage(~0.1V) via divider with pull high resistor when push "U" key. And will let KEYIN3 have no detection high pulse from KEYOUT7 during normal boot mode.

Did I do anything wrong or is there any other way?
Thanks,
Adam

Carlos Camargo wrote:
Hi Adam


Many  MP4 devices use resistor for that.

What do you think about this? :


Place a resistor between KEYIN3 and ground (so is necessary that you rotate a "1"  in KEYOUT[1:7]), connect BOOT_SEL0 directly to KEYOUT7, and to the pull-up resistor.

In normal operation, if you rotate a "1" in the keyout you read "0" in KEYIN3 if you don't press any key  (S18-S25)  because of resistor, if the user press any key (S18-S25) you can read "1"  in this line.


At boot time if you press the key "U" you connect BOOT_SEL0 to "0"  via resistor, for this is necessary that the ground resistor will be small that the pull-up resistor. There is a resisitive voltaje divider with Rpull-up and Resistor to ground. This make sense for you?


Carlos


On Wed, Aug 26, 2009 at 9:45 PM, Adam Wang <adam@qi-hardware.com> wrote:
Hi,

I need help with a change to the NanoNote board. I want to route the boot pins from the CPU (BOOT_SEL0/pin146 and BOOT_SEL2/pin145) so that you can just press the 'u' key<KEYOUT7, GPC16 & KEYIN3, GPD20> when pressing the power ON button to enable USB booting.

Unfortunately BOOT_SEL0 needs to be GND and I don't have a good idea how to easily connect the boot pins into the keyboard.

Does anybody have an idea?

http://github.com/adamwang
http://downloads.qi-hardware.com/hardware/qi_avt2/sch/


Thanks,
Adam


_______________________________________________
Qi Developer Mailing List
Mail to list (members only): developer@lists.qi-hardware.com
Subscribe or Unsubscribe: http://lists.qi-hardware.com/cgi-bin/mailman/listinfo/developer



--
Carlos Iván Camargo Bareño
Profesor Asistente
Departamento de Ingeniería Eléctrica y Electrónica
Universidad Nacional de Colombia
cicamargoba@unal.edu.co

_______________________________________________ Qi Developer Mailing List Mail to list (members only): developer@lists.qi-hardware.com Subscribe or Unsubscribe: http://lists.qi-hardware.com/cgi-bin/mailman/listinfo/developer


_______________________________________________
Qi Developer Mailing List
Mail to list (members only): developer@lists.qi-hardware.com
Subscribe or Unsubscribe: http://lists.qi-hardware.com/cgi-bin/mailman/listinfo/developer



--
Carlos Iván Camargo Bareño
Profesor Asistente
Departamento de Ingeniería Eléctrica y Electrónica
Universidad Nacional de Colombia
cicamargoba@unal.edu.co