-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi folks -
1) JACK_INSERT is generated using the routing switch in the headphone socket. If the headphone is inserted, the level on JACK_INSERT is simply defined by a 100K pullup to IO_3V3 via a 10K series resistor. But (according to the schematic symbol for that jack socket) if the headphone is not inserted, the level on JACK_INSERT is connected through to EP_R additionally. EP_R is the right audio amp output. It has a 1K pulldown on it after a 1uF series capacitor which is in itself OK. And there is a 10K series resistor to limit current into the CPU GPIO so it is okay for blowing it up with the negative voltages found here (although the protection diodes in the CPU will conduct and distort the audio waveform there slightly). But I noticed sometimes we wake immediately we sleep. A possible explanation seems that if the 1u cap is charged by the amp, maybe it can discharge through the 1K to GND after a little time and give us an edge to wake us. In addition, the Amp can therefore be implicated in any oscillation seen on JACK_INSERT as reported by, eg, Mickey. 2) HOLD button doesn't seem to work in the situation just the ALSA modules are loaded, it seems that MICBIAS is needed to be high to detect HOLD button and it is not high at that time. I found I can see ~50mV on the mic line and I can force that to 0V with the HOLD button, I guess this is all we can see from the 100K pullup which is defeated by the low resistance (900R I measured back home) across the Mic. But to do anything with HOLD we must have MICBIAS powered. Even then maybe we don't make enough high level to detect a logic '1' at CPU interrupt input considering the load of the Mic. - -Andy -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (GNU/Linux) Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org iD8DBQFHxrJtOjLpvpq7dMoRAlIEAJ42z6PPI10xlRIPkz7NE9am2+svvACfRTLW niDoInW+pTcZChZppsFUgII= =vd+x -----END PGP SIGNATURE-----
