PTAP: PT2399 tap tempo control

[bside2234]

Should I put the pull-up to 5v or 9v? Does it matter? Also, how would I calculate the value of the pull-up? What formula?

I'll disconnect the PT2399 and see if the digital pot tracks it.

[decc]

To 5V. Everything in the PTAP operates at 5V (including the LEDs).

The value doesn't really matter. 10k is fine, though whatever you have around between 1k and 100k would be OK. The current drawn is negligible so you don't have to worry about a voltage drop (and since this is configured as an analog input it doesn't even have to be a valid logic level.) You don't want to jumper directly to a voltage rail since the input can be configured by software to be a push-pull output, and while the chances of a glitch doing this is miniscule, better safe than sorry.

[bside2234]

Ok. So I opened it back up. I was going to do one thing at a time just so I know what it was that was wrong. First I put the pull-up resistor in and tested it. It worked!!! But wait! I put the bottom back on the pedal and it stopped working. That made me think there was a loose wire or something. Opened it back up and started poking at the wires (focusing on the 3 for the pot. Sure enough, I heard the chip calibrating. Reheated all the solder joints and presto! It works perfectly. I don't know if the pull-up resistor has any effect on it or not but it's there and doesn't have any negative affect at all.

So I can confirm that the PTAP2 does work with the Magnus. When I went to go get the schematic for the PTAP2 the other day, I noticed there was a PTAPH now. I ordered one 

Thank you for your help

[studiostud]

Hi decc,

Ordered one of your PTAPH units and looking forward to receiving it soon!  I had a question about the schematic because I'd like to create my own layout for the circuit.  On the ATtiny44, you have Pin12 going to "mode_led" which looks like it is the same as "T4".  What is this LED for?  Is it to indicate that the pedal is in tap mode and it is a separate LED from the tempo LED? If that is the case, how do I wire up this LED?  Do I connect T4 to the anode of an LED and then connect the cathode to GND?  Is there a resistor involved?

[studiostud]

Hey everyone,

I created a PCB layout for the PTAPH.  I noticed that someone has already posted a layout for the original PTAP so I wanted to contribute by posting this for people that want to utilize the PTAP with the added tempo LED indicator.  I have not received my PTAPH unit in the mail yet so I have not had the chance to verify this layout.  Let me know if there are any errors and I will make the changes and re-post the image.  I can also post an editable PDF of the transfer image that will make it the right size for printing if it is requested.

*MODERATORS* : I apologize if I am overstepping my bounds by posting this image.  Let me know if it needs to be removed and I will do so.

[studiostud]

DECC -

Question for you.  Would it be easy to program into the chip a way to use a rotary switch to change the timing increments?  I've been looking into another thread for building a tap tempo'd tremolo and the chip that is used for that has the ability to use a rotary to switch between 1/4 note, 1/8th note, triplets, etc...  I was just wondering if there were options to be able to do this with your chip as well?  Could be something really cool that would make it even more versatile. 

Jeff

[Taylor]

Since the PTAP's pot input is, I think, a voltage divider between the positive and negative rails, it would work exactly the same as the rotary switch for the tap tempo trem. But then you'd be limited to a set number of delay times, so I'm not sure I see why you'd want to do that.

[decc]

Hey, I'm back from the dead, questions answered:

Hi decc,

Ordered one of your PTAPH units and looking forward to receiving it soon!  I had a question about the schematic because I'd like to create my own layout for the circuit.  On the ATtiny44, you have Pin12 going to "mode_led" which looks like it is the same as "T4".  What is this LED for?  Is it to indicate that the pedal is in tap mode and it is a separate LED from the tempo LED? If that is the case, how do I wire up this LED?  Do I connect T4 to the anode of an LED and then connect the cathode to GND?  Is there a resistor involved?

The "mode_led" pin is for the serial/parallel more indicator for the PTAP2 configuration. It doesn't do anything in the PTAPH but I copied over the schematic from the PTAP2 and the label stuck. Leave it disconnected.

Since the PTAP's pot input is, I think, a voltage divider between the positive and negative rails, it would work exactly the same as the rotary switch for the tap tempo trem. But then you'd be limited to a set number of delay times, so I'm not sure I see why you'd want to do that.

That's correct, it's just a voltage divider. Though I do imagine the usefulness of the option of having the manual delay knob and the tempo beat knob being separated. It's a good idea for a future feature anyway.

[Beo]

Hey Decc, are you still around? Your website has been off-line for a while. Does this mean you are no longer supporting / selling PTAP / PTAP2?

Travis

[bside2234]

Yeah, I've been wanting some for a little while now and the site has been down. Wish I knew how to do this myself.

[Beo]

If for any reason Decc isn't supporting it or selling it any more, I wonder if he'd be interested in turning the code over as open source so that the community could start burning our own.

[bside2234]

If I knew how to do it, I would do it for us. I just don't have a clue.

[Taylor]

There's always the new taptation:

http://www.diystompboxes.com/smfforum/index.php?topic=86294.0

[jkokura]

Uhhh...

There isn't really. The store has sold out, and tonegod hasn't answered yet as to whether more will be available...

Jacob

[Taylor]

Oh. I haven't really been following it... oops.

Has anyone emailed decc? He may not be checking here too much. I have his email if you guys want me to mail him and see what's up.

[bside2234]

Please do. Thanks.

[Beo]

Tonegod replied on the other thread.  Looks like a new batch of taptations are on their way to the Aron already. I'll order one for sure.

[bside2234]

I wish I could get some PTAP's though. I already have boards etched. It looks like I might have to try to figure out how to do it myself even though I think it's way beyond me. Off to an AVR forum 

[Taylor]

I emailed decc, but no response. 

[bside2234]

Well great! Thanks though. If someone can point me in the right direction, I'll see what I can do to make these. I'll see what I can find out. I've already started reading some stuff and it seems pretty nuts. Maybe we could get together on here and do a collaboration to get the PTAP going again. If I had code and the knowhow to program the chip, I'd certainly take the time to make them available. I just don't want to step on Decc's toes if he plans on doing this anymore.