AP-8 RevD No Sound when connected to Prop 1

[Jadams]

The AP-8 has been working fine.  I disconnected from the Prop 1 to work on another project.  When I reconnected, no sound.  I found I had connected the cable from the Prop to the AP-8 wrong.  On the AP-8 side, I reversed the connection.  When I corrected it, still no sound.  I can push the play button, and play a segment.  Did I destroy it??

[Jadams]

After swapping Prop 1s and AP-8s, the problem was with P7 on one of the  Props.  The AP-8 works fine.

[JonnyMac]

First, this just showed up in the forums even though the initial post was on the 18th -- sorry for the delay.

How are you connecting the Prop-1 to the AP-8?  We always recommend a serial connection for the best flexibility and to prevent electrical problems.  If you want to use the "P" input of the AP-8 the best course is to cut one end of the extension wire, connect the black wire to the GND terminal, the white wire to the OUTx terminal of your choice, and do not use the red wire.

Now you can turn on an output which will mimic pressing the Play button.

Yes, you can do this by going from the P7 header to the Play header of the AP-8, but if you press the play button on the AP-8 while P7 is HIGH you will short out the pin and could "pop" it.  That might be what happened; the rest of the board is probably fine.

[Jadams]

I use the serial connection as different inputs in my program tirgger different segements on the AP-8. 

Again, I disconnected the Prop 1 (let's call it Prop A) to do another project, reconnected and had no sound.  I connected a RC-4 to Prop A just for a test and found it didn't work either.  Next I attached another Prop 1 (Prop B) and everything works.  I removed the ULN2203 from Prop A and connected the AP-8 to P6 header and it worked.  Something must be wrong with the P7 header.  I may have done as you suggested, hit play when P7 was high.

Anyway, I'm back in business, will probably order a replacement Prop 1.

[JonnyMac]

If you want to simulate a Play press when going header to header, you can do it like this:

Play_AP8:
 LOW 7
 PAUSE 250
 INPUT 7

The Play input on the AP-8 is active-low which means the play switch connects between that input and ground -- hence the possible shorting of the pin if it was HIGH when you pressed the Play button.  The little code snippet above simulates the press by taking the pin LOW, then releases the pin by making it an input.  We don't use the INPUT command very often; this is where it's useful.

[Jadams]

I'm really confused now.  Yesterday, I swapped out the Props and was able to run the AP-8_Cycler.Bs1 program using the serial connection to the P7 header.  Today, after doing nothing more than turning it on, it does not play.  The debug terminal gets to Playing #0 and hangs there.  I reloaded the program several times and no deal.

For now I'll use your suggestion on the last post, using the play input command.

Any ideas on the serial connection problem?

[Jadams]

Please disreguard the last post.  My error.............fat fingers.