# New Relay Bypass Module (Instant Switching)



## Robert




----------



## cooder

Oooooooh nice.... suspense is killin' me....


----------



## jubal81

Game changer right here. Can't wait to get my hands on a few of these.


----------



## DGWVI

Will three channels be the max, or will it be expandable?


----------



## Robert

You can add as many as you need.


----------



## Devoureddeth

I guess you can make an easy looper now. Lots of possibilities.


----------



## jubal81

Would it be possible to add some simple programming to the program? It'd be pretty useful to make it so holding down multiple buttons simultaniously for 5 seconds puts them in a group where they turn each other off if activated. Hold down a lone button to make it independent. 

This would allow for stacking or 'one-of-X' operation.


----------



## Robert

jubal81 said:


> Would it be possible to add some simple programming to the program? It'd be pretty useful to make it so holding down multiple buttons simultaniously for 5 seconds puts them in a group where they turn each other off if activated. Hold down a lone button to make it independent.
> 
> This would allow for stacking or 'one-of-X' operation.



Not in this particular version, but you could hard wire them in groups.    This is aimed at one-at-a-time channel switching type behavior.


----------



## jubal81

Gotcha. Does it use a UC or a switching chip like the MAX16054?


----------



## Robert

It uses the same microcontroller (and updated PCB) as the Intelligent Relay Bypass module.


----------



## Gordo

This is sick.


----------



## Moltenmetalburn

the intelligent relay pcb is about to be updated?
I just built 8 of them. :/

I also had two questions about them:

 Any way to add led when using the old relay board for a external bypass looper?

And when not mating to one of your other pcb what is the SW pad for?


----------



## Robert

Moltenmetalburn said:


> the intelligent relay pcb is about to be updated?
> I just built 8 of them. :/
> 
> I also had two questions about them:
> 
> Any way to add led when using the old relay board for a external bypass looper?
> 
> And when not mating to one of your other pcb what is the SW pad for?



This will most likely be a separate release, not a replacement for the existing module.    The channel switching module loses the momentary and auto-on functions of the Intelligent Relay Bypass module.

The SW pad is the ground path for the LED on PedalPCB boards.   It can be ignored for any other build that doesn't require it.

You can connect an LED directly to the relay bypass board if desired:
Replace R1 with a 1K resistor (instead of 10K)
Omit Q1, install LED Anode/Cathode in pads of Q1 as shown below


----------



## Moltenmetalburn

Thank you so much for the detailed explanation. I am excited about the new module also.


----------



## DGWVI

Any update on this?


----------



## Robert

DGWVI said:


> Any update on this?



The boards and firmware are complete and ready to go, I just need to build up a set and verify that everything works properly on the new PCB.

Hopefully I can do that later today.


----------



## DGWVI

Robert said:


> The boards and firmware are complete and ready to go, I just need to build up a set and verify that everything works properly on the new PCB.
> 
> Hopefully I can do that later today.


AWESOME! Been waiting on these so I can complete my huge multifx, and make it all PedalPCB


----------



## Robert

Alright, the Intelligent Relay Bypass module has been updated to include Channel Switching mode.  Any order shipping from today forward will include this update.

Holding down the footswitch at power on cycles modes.
1 - Normal
2 - Auto-Power On
3 - Channel Switching


----------



## zgrav

I like the option to place the order and have it ship when the product is back in stock.


----------



## Robert

zgrav said:


> I like the option to place the order and have it ship when the product is back in stock.



Normally backorders are too complicated to keep up with, the cart system isn't really designed for it...    In this case we're just waiting on more microcontrollers and they'll be here Wednesday so it shouldn't cause too much trouble.


----------



## jubal81

Robert said:


> Normally backorders are too complicated to keep up with, the cart system isn't really designed for it...    In this case we're just waiting on more microcontrollers and they'll be here Wednesday so it shouldn't cause too much trouble.



Any chance we'll see the programmed chips as a standalone item in the store?


----------



## Robert

jubal81 said:


> Any chance we'll see the programmed chips as a standalone item in the store?



I never really thought about it.   If that's something you'd want it's definitely possible.


----------



## jubal81

Robert said:


> I never really thought about it.   If that's something you'd want it's definitely possible.



It'd be really useful for me. I'd like to make some dedicated PCBs to control 2- and 3-effect multis that I can match up to my layout configuration.


----------



## Gordo

How does the channel switching work?


----------



## Robert

I need to get the updated build docs posted....

Basically just install them like normal but connect them together by the CTRL pad.     Then switch the module to Channel Switching mode by holding down the footswitch while applying power (three times).

One other note, there is a 100K resistor on the board.   This is only used for Channel Switching mode and you only need one installed.    It'll work if you install one on each of the boards, but it's not necessary.    You don't need it at all if you don't plan to use Channel Switching mode (for example in a single pedal).


----------



## Gordo

Aahh, that's it then.  The docs and the image don't show a CTRL pad.  I take it that when you set the mode it stays there thru subsequent power ups until you set it again.  I'm trying to picture plugging in the power supply while holding down all the buttons and repeating two more times.  Sounds like a 3 Stooges routine.


----------



## Robert

You don't have to hold them all down together, just set one at a time.  This also allows you to remove a circuit from the switching bus for independant operation.

Yep, the setting will persist until you change it again.


----------



## a7v7

Is the source code available (on github maybe)?


----------



## Robert

a7v7 said:


> Is the source code available (on github maybe)?



It's not an open source project at the moment...   maybe one day.


----------



## DGWVI

Robert said:


> I need to get the updated build docs posted....



Any update on this?


----------



## GuitarBuilder

I got the latest board and was surprised to see it quite different from the build document.  Most of my questions were answered above, but I still have a few:

1.  What happened to the "old" R2 (47K)?  Is it no longer necessary to pull up pin 2 on the ATTINY85?
2.  Could you please clarify "Then switch the module to Channel Switching mode by holding down the foot switch while applying power (three times)" - does this mean turning power on and off three times?
3.  Would it be possible to connect multiple relays in parallel to pins 6 and 7 on the ATTINY85?  Is there a current limitation?

Thanks!


----------



## Robert

GuitarBuilder said:


> I got the latest board and was surprised to see it quite different from the build document.  Most of my questions were answered above, but I still have a few:


1) The 47K pull-up resistor is no longer required.   The internal pull-up of the ATTINY is used now.
2) Holding down the footswitch when applying power cycles to the next mode.  You would actually do this two times on a stock board to put the board into channel switching mode.    (Standard / Auto-Power On / Channel Switching)
3) The ATTINY I/O pins can source up to 40mA.   The TQ2-L-5V coil current is rated at 20mA, so two in parallel would be pushing it.   I'd also be concerned that flyback voltage from one coil _might _trigger the other.


----------



## GuitarBuilder

Slightly different question:

I'd like to control six of these boards at once with only one momentary switch, no channel switching.  Can this be done?  If so, is any special isolation required between boards?


----------



## Robert

I've never tried this, but it _might_ work.

You might want to isolate them using a diode to prevent the pull-up resistors of all six relay modules from being in parallel. 


Substitute the wire going from the footswitch to the lower FS pad of each relay module with a signal diode (1N4148, 1N914, etc), anode towards the PCB.   

The cathode of all six diodes would connect to the footswitch.

You'd only need to connect the other lug of the footswitch to any one of the PCBs (square FS pad).


----------



## GuitarBuilder

Robert said:


> I've never tried this, but it _might_ work.
> 
> You might want to isolate them using a diode to prevent the pull-up resistors of all six relay modules from being in parallel.
> 
> 
> Substitute the wire going from the footswitch to the lower FS pad of each relay module with a signal diode (1N4148, 1N914, etc), anode towards the PCB.
> 
> The cathode of all six diodes would connect to the footswitch.
> 
> You'd only need to connect the other lug of the footswitch to any one of the PCBs (square FS pad).


I'll try it and report back - thanks!


----------



## Grubb

Is it possible to integrate midi with the intelligent relay bypass module? Basically I want the channel switching mode to work as advertised but also for the pedal to respond to midi commands for selecting channels or bypassing the unit. Any idea how to go about it?

Edit: I suppose I could get similar functionality through external switches like for changing an amp channel. Could I get the IRB module to respond to external control voltage?


----------



## GuitarBuilder

Robert said:


> I've never tried this, but it _might_ work.
> 
> You might want to isolate them using a diode to prevent the pull-up resistors of all six relay modules from being in parallel.
> 
> 
> Substitute the wire going from the footswitch to the lower FS pad of each relay module with a signal diode (1N4148, 1N914, etc), anode towards the PCB.
> 
> The cathode of all six diodes would connect to the footswitch.
> 
> You'd only need to connect the other lug of the footswitch to any one of the PCBs (square FS pad).


I’m happy to report that the diode logic works and one can switch multiple boards with only one push button.  I’ve also verified operation with a logic pulse in parallel with the push button switch.


----------



## squarewavesurfer

Does anyone know why i have to hold the momentary footswitch down for ~2-3 seconds to get the relay to turn on and off the effect?  Shouldn't it turn on and off almost instantly?  When i quickly depress the footswitch nothing happens at all.  When i depress the switch and hold for 2-3 seconds i then hear the relay click on and the effect will stay on.  To turn the repeat effect off I have to repeat the process of pressing and hold down the switch and then the relay will disengage.


----------



## Robert

That's definitely not normal operation.     Does the LED blink when you hold down the footswitch?


----------



## squarewavesurfer

Robert said:


> That's definitely not normal operation.     Does the LED blink when you hold down the footswitch?


I will check this evening, I haven't installed the led yet


----------



## squarewavesurfer

squarewavesurfer said:


> I will check this evening, I haven't installed the led yet


When i hold the footswitch down the led blinks 3 times.


----------



## Robert

Check your wiring, look for any solder splashes or stray wire strands.

It sounds like you might be shorting one of the supply rails (9V or 5V) to ground.

The LED should only blink when power is applied to the circuit while holding down the footswitch simultaneously.   If the LED blinks while you're holding down the footswitch then the microcontroller is restarting for some reason.

My _guess _is that holding down the footswitch is putting an excessive load on the 5V line for some reason and the regulator is dropping out momentarily, causing a full reset condition to occur.


----------



## squarewavesurfer

I haven't found any bridges connections.  Everything is connected as per the schematic.  One question I have is the microcontroller that came with my pcb is the ATtiny25V.  It looks like it is supposed to be a ATtiny85V.  Could this make any difference?  As far as I can tell the 25 just has less memory.


----------



## Robert

It could ship with the ATTINY13, ATTINY25, or ATTINY85 depending on what is available at the time.


----------



## fig

I need to test the one I built. It keeps looking at me.


----------



## squarewavesurfer

I recreated the circuit on a breadboard (minus the audio input/outputs and ctrl transistor and r3) using the same Panasonic latching relay, ATtiny25V and new 5V regulator (just in case).

The switching sometimes works instantly but then it reverts back to needing to hold the switch down.  The LED blinks 2 sets of 3 or 4 quick blinks before the relay switches on.  If I keep shorting the switch a bunch of times i can get it back to instant switching for a while but it is inconsistent.  Any ideas?  Should i order a new relay and ATtiny?


----------



## squarewavesurfer

I was able to get it working perfectly by removing the 22p cap (C3).  I believe this cap is being used as a method of debouncing the switch.  I am not sure why this fixed it but it worked for my breadboard test and in the pedal circuit on the intelligent relay bypass pcb.  It turns on or off instantly every time and when I hold the switch down I get the momentary on or momentary off function as intended.


----------

