Hi, I'm trying to generate 8 channel I2S audio with BBB.
I'd like to use these data output pins: P9_28 - C12/2 - mcasp0_axr2 P9_27 - C13/2 - mcasp0_axr3 P9_30 - D12/0 - mcasp0_axr0 P9_41 - D13/0 - mcasp0_axr1 I've set pinctrl-single: - ... - 0x1a8 0x08 /* mcasp0_axr1, MUX_MODE0 | PIN_OUTPUT */ - 0x1b4 0x2f /* xdma_event_intr1.gpio0_20, MUX_MODE7 | PIN_INPUT */ And also I've removed all other occurences of 0x1b4 and 0x1a8 from the device tree. The problem is that on P9_41 there is not AXR1 output, but 0.3V signal with some EMI spikes of 32.768kHz frequency generated probably by CLKOUT2. If I route AXR1 to P8_31 instead of P9_41 the multichannel audio works fine. But I'd like to have HDMI output, which required P8_31. The BBB_SCH.pdf is a bit different regarding those pins than it is draw on gerber files. There is chance that desoldering R19 could help, if the 0.3V and EMI spikes are generated by CLKOUT2 processor pin. But I've not tried that. Moreover CLKOUT2 pin is routed also to JTAG P2 header, so there is chance that unwanted 32.768kHz signal is received on that trace. Any ideas? Miero --- Background info: I'm writing driver for I2S cape with two low jitter clocks: http://www.diyaudio.com/forums/twisted-pear/250583-building-open-embedded-audio-applicance-11.html#post3857233 -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
