DOUT Issue

Testing/Troubleshooting
1

I have a DOUT board connected to a Core32 board along with a DIN board and I’m getting some weird behaviour.

Basically, the only way I can get the DOUT LEDs to work is by physically touching the pin of DOUT IC1 which connects to DOUT J1:S0 (I can even do it by hovering my finger close to said pin). When I do this, all connected LEDs light up, but still do not respond to the MIOS32 PinSet function. Sometimes, during startup, all connected LEDs will turn on for a few seconds and then all off.

extern "C" void APP_DIN_NotifyToggle(u32 pin, u32 pin_value)

{

	MIOS32_BOARD_LED_Set(1, ~MIOS32_BOARD_LED_Get());


	MIOS32_MIDI_SendDebugMessage("APP_DIN_NotifyToggle(%u, %u)", pin, pin_value);


	MIOS32_MIDI_SendDebugMessage("1-Pin0: %u", MIOS32_DOUT_PinGet(0));

	MIOS32_DOUT_PinSet(0, pin_value);

	MIOS32_MIDI_SendDebugMessage("2-Pin0: %u", MIOS32_DOUT_PinGet(0));

}

When I toggle the DIN button, the Core32 Status LED toggles, and I get the following in MIOS Studio terminal, but I get no DOUT LEDs functioning.

[94518.016] APP_DIN_NotifyToggle(0, 1)

[94518.016] 1-Pin0: 0

[94518.016] 2-Pin0: 1

[94518.245] APP_DIN_NotifyToggle(0, 0)

[94518.245] 1-Pin0: 1

[94518.245] 2-Pin0: 0

What have I missed? I’ve tried a couple of DOUT boards, checked for shorts on both, popped IC1 out and then put it back in, and made up a new ribbon cable connecting J8 and DOUT:J1 - no luck :frowning:

2

Hi,

I had a few issues with DOUT boards too.

I found that I had R31 SIL resistors fitted the wrong way round in the core32, check that the spot on R31 aligns with the marking on the board.

Make sure that the ribbon cable is correct at the DOUT end, if you are using a SmashTV board then the connections are on the inner (that is closest to the first shift register) edge of the connector J1. The DIN chain connects to the outer edge of DIN J1 on the SmashTV boards.

I found that things worked better when the DOUT chain was terminated as recommended by TK. I think this info should be in the documentation somewhere.

Also make sure that the DOUT cable is in J8 and the 5V0 jumper is set on J8.

Hope some of this helps.

Good Luck

Tim

3

Thanks Tim,

Checked all the things you said, no luck so far, thought I couldn’t find anything on how to terminate the DOUT chain?

Thanks

4

Thanks Tim,

Checked all the things you said, no luck so far, thought I couldn’t find anything on how to terminate the DOUT chain?

Thanks

Sorry, I should have included the link to this http://ucapps.de/midibox_seq/mbseq_v4_dout.pdf

This is the only reference that I can find but I am sure it is mentioned elsewhere.

Tim

5

The termination is (normaly) only required if multiple DIN/DOUT SRs are chained in mixed order like I did for MBSEQ (today I wouldn’t do it this way anymore)

It shouldn’t be required if DIN and DOUT modules are connected in separate chains.

Important: the cables should be as short as possible, between Core and the first DIN/DOUT module not longer than 30 cm!

If this doesn’t help, it’s definitely related to the pull-up resistors. The 220 Ohm array has to be used! (neither 1k nor 10k)

Best Regards, Thorsten.

6

I suggested the termination of the chains as this worked for me. I was using quite long cables so perhaps this was adding to the problems I had.

Tim.

7

The cables are short, maximum 10cm.

Are these the correct resistor networks? (I don’t have a multimeter on me at the moment)

4116R LF

1-221

_ _ C1019


(_ are symbols I cannot type)
8

Yes, the network is correct, 221 means 22*10^1 = 220 Ohm

Hm… another possibility: could it be that the LED is connected to the wrong DOUT pin?

How many LEDs are already connected? Only one?

Do you know that DOUT Pin #0 is assigned to the leftmost output pin of the MBHP_DOUT_DINX4 module (J4:D7), and not to J4:D0?

Best Regards, Thorsten.

9

Make sure that the ribbon cable is correct at the DOUT end, if you are using a SmashTV board then the connections are on the inner (that is closest to the first shift register) edge of the connector J1. The DIN chain connects to the outer edge of DIN J1 on the SmashTV boards.

Thanks Tim, I had previously had it connected similar to my DIN boards as that was the only way I was getting any LED activity (not a very good troubleshooting method, I’ll admit :blush:).

Do you know that DOUT Pin #0 is assigned to the leftmost output pin of the MBHP_DOUT_DINX4 module (J4:D7), and not to J4:D0?

Thanks TK! When I read that, I remembered skimming across something about that on the DOUT pin table wiki page. Seems to be working OK, haven’t done much testing though. Thanks again!