Author Topic: Simulating multiple button presses?  (Read 3452 times)

calan

Simulating multiple button presses?
« on: September 25, 2015, 09:07:38 PM »
Let's say I have a stompbox with the typical Boss/Digitech style foot switch, and this box uses a pedal press to increment through 4 presets.

Has anyone designed a circuit that would connect to the switch contacts, and simulate 1,2,3, or 4 presses in rapid succession? Basically an external box with 4 separate switches, for rapid access to any of the four patches with one click.

It seems like you could just have each switch generate the required number of pulses... but I'm not sure how to implement it, or how you would insure that it always counts from the first position.

Thoughts?

SISKO

Re: Simulating multiple button presses?
« Reply #1 on: September 27, 2015, 11:03:26 PM »
It can be done with a few cmos gates. Let me think about it, but it would not be much diferent than  The tone god VBainishig Point...

Swtich, oscillator, counter, reset.

You are limitated to the maximum speed response of the preset counter

 
--Is there any body out there??--

Hatredman

Re: Simulating multiple button presses?
« Reply #2 on: September 28, 2015, 12:14:36 AM »
4017
Kirk Hammet invented the Burst Box.

caldersm

Re: Simulating multiple button presses?
« Reply #3 on: September 28, 2015, 10:34:38 AM »
What is the timing for the pulses....?  How long are the pulses and how long between them...?

You could put a little 8 pin CPU to do the pulses.....wouldn't take but an hour to pop out some code.  They cost about $1.50 each.

Let me know if you are interested, and I can help you get it working.

Steve

calan

Re: Simulating multiple button presses?
« Reply #4 on: October 02, 2015, 04:20:49 PM »
What is the timing for the pulses....?  How long are the pulses and how long between them...?

You could put a little 8 pin CPU to do the pulses.....wouldn't take but an hour to pop out some code.  They cost about $1.50 each.

Let me know if you are interested, and I can help you get it working.

Steve

Something like...press a momentary switch, get 3 pulses out over a period of 500ms, with a pulse duration of maybe 100-150ms. That's a rough guess...it would be dependent on the reaction time of the effects circuit and whatever footswitch debouncing it incorporates. I'm mostly just spitballing right now, and haven't actually looked into the details of doing it yet.

*****

35 years of tinkering with electronics, building computers, and writing application software... and for some stupid reason I've never once learned how to program and use a PIC.

I would LOVE to be able to use a PIC. I can think of several things it would come in handy for.

I've looked around the web a bit, but there is so much info that it's overwhelming. Can you recommend a one-stop-everything-you-need kit that would let me set up a simple in/out type chip, with the multiple pulse generation idea in mind?

On a side note, what would be the best way to interface the PIC pulses with the switch contacts of a stompbox or multi-effects unit?

Thanks much!
« Last Edit: October 02, 2015, 04:23:50 PM by calan »

ElectricDruid

Re: Simulating multiple button presses?
« Reply #5 on: October 04, 2015, 04:43:36 PM »
On a side note, what would be the best way to interface the PIC pulses with the switch contacts of a stompbox or multi-effects unit?

I'd use the 5V output from the PIC via a 10K to the base of a transistor (say BC547 or 2N3904). Then you've got a switch between collector-emitter which will turn 'on' when the PIC output goes high.
For some pedals, you might be wiring the collector-emitter across the switch to mimic the switch turning on (essentially putting the transistor in parallel as a secondary switch). For others, you might be looking at a short-to-ground arrangement, in which case, you could ground the emitter, and just connect the collector to the switch. This is quite often the case for external foot switches (like sustain pedals, for example) and also often the case for switch inputs in microprocessor-based units (you mentioned multi-fx). They often have inputs tied high by a pull-up resistor (or an internal pull-up) and then shorted to ground by a simple momentary switch. Latching switches and other functionality can be implemented in software, so often this is all the hardware you see.
Usual disclaimers apply - this is guess work based on what *I've* seen, not on what you've got in front of you.

HTH,
Tom

caldersm

Re: Simulating multiple button presses?
« Reply #6 on: October 05, 2015, 10:23:50 AM »
Hardware wise, I would agree with Tom....using a separate transistor will isolate each output better.  I am still a bit confused as to what you are tying this to.....I had imagined some switching device that requires pulses from a switch to determine which foot pedal to use...?  Correct..?   So there is only one switch now....and you press it once to go to the first one.....four times to go to the fourth one...etc...?

I don't use PIC....I use AVR....programming it using Arduino, just because I learned that first.  You can get an Arduino starter kit, and learn the programming language and wiring pretty cheaply.  It starts at ground zero, and walks you through learning to code and download and test.  After you get it working on the main board, then you can burn the software into a stand alone chips called Attiny's....they come in all sizes and start in cost of about a dollar.  I have written programs from modulating a colored LED for one of my son's toys to a very elaborate programmable Looper.

Here is the starter Kit for $25:  http://www.amazon.com/SainSmart-New-Basic-Starter-Arduino/dp/B00UV7KAPM/ref=sr_1_18?s=pc&ie=UTF8&qid=1444052131&sr=1-18&keywords=Arduino+Starter+Kit

PDF Tutorial for the kit is available here: http://www.selloutsoon.com/albums/documents/20-013-130-139/SainSmart-Leonardo-kit.zip

Arduino website learning:  https://www.arduino.cc/en/Guide/HomePage

Programming the sequence you are asking for will be pretty easy:

Which switch was pressed? (1 - 4)
Debounce switch
Output number of pulses based on switch number.
Start over.

I could write, test and debug it in a couple hours for you, if you decide to buy the hardware above.

Steve