In the case where I2C isn't being used for anything else, is there an obvious reason why the shutdown doesn't work 100% reliably with GPIO3? The hardwired resistor value of 1k8 is quite a lot lower than the value suggested for external pull-up resistors (e.g. 10k), and it's not possible without a bit of surgery to add another resistor. I understand this low value is the minimum required to limit the current sufficiently, whilst also allowing the pin to handle high speed voltage changes.
But I wonder if a bit of downstream resistance (i.e. between the pin and GND) would be enough to split the 3v3 voltage so that GPIO3 doesn't actually go low enough to register '0'. I can't see an obvious way to do anything about that if that is the case, and also it doesn't explain why the wake-from-halt function works reliably. Maybe some measurements will throw light on this. Actually, it would need about 500 Ohms between the pin and ground to keep GPIO3 close the the 'zero' threshold of 0.8V, so I doubt this is the problem. ------------------------------------------------------------------------ chill's Profile: http://forums.slimdevices.com/member.php?userid=10839 View this thread: http://forums.slimdevices.com/showthread.php?t=109270 _______________________________________________ unix mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/unix
