On Sunday 02 May 2010 17:57:49 Stefan Schmidt wrote: > Hello. > > On Sun, 2010-05-02 at 17:42, Christoph Mair wrote:
> > Unfortunately the NOR bootloader does not work when both, pressure sensor > > and navigation board, are connected (somebody knows why?). :) > > Wild guess. You are not (ab-)using the H-TP4711 testpad which is pin 32 on > the debug connector? That one is the write protect disable pin for the > NOR. No, during my tests I just connected both devices to the aux-switch (for power) and to to the I2C bus. Then the NOR u-boot did not start when I pressed the aux key (at least it did not enable the display). Disconnecting one of the bus lines (SCL or SDA) or the power supply fixed the problem. I guess this may be because NOR u-boot uses a slower frequency than the linux kernel, but I can't come up with a meaningful expanation for this. I even increased the bus capacitance for one line by adding a 400pF capacitor between SCL and GND. Normally this is the stupiest thing to do, but it "fixed" the NOR u-boot with the tradeoff that Linux did not boot. :P The wiki mentions possible problems (http://wiki.openmoko.org/wiki/I2C#Powering_additional_I2C_devices), but excludes the NOR u-boot. Best regards, Christoph _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community