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ADPD105 Eval Board - No signal on Channel 1-2 with external connected photo diode on P3/Pin3

I'm trying to connect two photo diodes for channel 1-2 and channel 3-4 on the ADPD105 Eval Board

On P3 I used
pin 1 for common cathode
pin 2 for channel 3-4 anode first photo diode
pin 3 for channel 1-2 anode second photo diode

and of course I removed jumper on P7 to disable the onboard photo diode.

Using the APDP OpenMarket Wave Tool 1.0.11.1 the channels 1 and 2 are constantly "0".
I already did an cross check and swapped the photo diodes on pin 2 and 3. Again I see the signal only on channel 3 and 4. So I am sure both photo diodes deliver a signal, but I only see values for channel 3 and 4.

Time Slot Switch (Register 0x14)
SLOTB_PD_SEL: 0x5: PD1-2 is connected to Channel 1 and Channel 2; PD3-4 is connected to Channel 3 and Channel 4 during Time Slot B.
SLOTA_PD_SEL: 0x5: PD1-2 is connected to Channel 1 and Channel 2; PD3-4 is connected to Channel 3 and Channel 4 during Time Slot A.

Any idea, why I don't see a signal in channel 1 and 2 in the APDP OpenMarket Wave Tool?

Many Thanks
Peter

  • I found the problem by myself:
    I was the offset for channel 1 and 2 which set to 3FFF by the default configuration for the PPG delivered with the wave tool.

    Set
    SLOTA_CH1_OFFSET,
    SLOTA_CH2_OFFSET, 
    SLOTB_CH1_OFFSET, 
    SLOTB_CH2_OFFSET
    to 1F80 as done in the default configuration for channel 3 and 4

    ...and the channels 1 and 2 deliver valid signals :-)