A10s Microphone input

Started by zsara, September 23, 2013, 01:28:29 PM

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how should be an external microphone connected to the Olimex A10s board? I connected it to pins MICIN1 and MICM of MIC/TV header. I tried the microphone supply both from VMIC and +3.3V pin. With the VMIC pin it isn't clear if an external resistor 2k2 must be used or not so I tried both possibilities. But microphone still doesn't work. Could anybody help?


Have you made any progress on this?  I too need to get the mic working on my A10S board.  Any links you can give to the external microphone circuitry you've already discovered would be greatly appreciated.


I found the microphone circuit for the A10/A20 board at http://dl.linux-sunxi.org/A20/a20_pad_std_v1_1.pdf.  Look at row A on page 19/20.  The microphone sits between MICM (-ve) and MICIN1 (+ve) with MICIN1 being pulled up to VMIC.  MICM is derived from VRA1 - see location C3 on page 9.