Hey there,
I am almost done with the design of an arduino nano based tap tempo control board with modulation. Control of a single PT2399 delay works perfect, also modulation works quite nicely. Modulation depth is controlled via a second digital pot. I programmed a calibration routine for the whole setup, so tapped tempo and resulting delay will be very precise, disregarding the 30% tolerances that digital pots come with. With this being said, I think that the setup should be able to work for multiple PT2399 delays like the MBP Deathclaw as well. Can somebody confirm this?
Quick explanation of the schematic (excerpt) below:
T2 is fed with an oscillating signal, therefore pin 7 of the MCP41010 is fed with an oscialting resistance against ground. The digitally controlled resistance of the MCP41010 "mixes" the oscillating signal with a fixed ground signal from Pin 5/6. This "mix" is fed to the deathclaw resistors (basically a "shaking ground" :-)).
MCP41050 again controls the two BC550s in the deathclaw schematic, controlling the average delay time (which again varies with the "shaking ground" around that value).
I think that compared to other approaches (http://www.madbeanpedals.com/forum/index.php?topic=8053.0), this should work, as I have control over the MCP settings via the arduino.
i wish i had something to offer other than my money when this is finished... ;)
Quote from: flanagan0718 on March 23, 2016, 01:23:38 PM
i wish i had something to offer other than my money when this is finished... ;)
I wish somebody would offer to try it with a deathclaw (or any other similar approach). I am quite happy with my deep blue delay (single PT2399) and the way this thing works with that. I have buttons for tap tempo, subdivision, modulation on/off, up to three presets, rotary encoders for delay time, depth and speed. Still thinking about PCB design (as small as possible with a lot of offboard wiring or for a 1590B with pcb-mounted pots).
Considering I know jack squat about this stuff (though I'm a C# developer by day), is this more accurate than the Taptation?
Quote from: daleykd on March 23, 2016, 02:51:23 PM
Considering I know jack squat about this stuff (though I'm a C# developer by day), is this more accurate than the Taptation?
I never built the taptation, but it works like this: The microprocessor is hooked up to the input and output of the delay. It sets the digital pot to zero resistance and measures the delay time by sending out audio beeps and measuring the audio delay it receives from the delay output. This is repeated for increasing values of resistance for the digital pot up to the maximum resistance. Tolerance of the digital pot (and the pt2399) thus does not matter, because the controller stores the setting specific to your components.
This calibration has to be done only once.
How do you like that? ;)
Quote from: daleykd on March 23, 2016, 02:51:23 PM
Considering I know jack squat about this stuff (though I'm a C# developer by day), is this more accurate than the Taptation?
I should mention, that modulation with a PT2399 will always have a (neglegtable, IMHO) effect on the perceived accuracy. But with unmodulated delays, this IS precise.
Quote from: mfunky on March 23, 2016, 03:00:53 PM
I should mention, that modulation with a PT2399 will always have a (neglegtable, IMHO) effect on the perceived accuracy. But with unmodulated delays, this IS precise.
So, I can use a DBD with this with precision? TAKE MY MONEY NOW!
Quote from: daleykd on March 23, 2016, 03:15:19 PM
Quote from: mfunky on March 23, 2016, 03:00:53 PM
I should mention, that modulation with a PT2399 will always have a (neglegtable, IMHO) effect on the perceived accuracy. But with unmodulated delays, this IS precise.
So, I can use a DBD with this with precision? TAKE MY MONEY NOW!
Yes, you can. For the time being, you would have to live with THIS, though:
Quote from: mfunky on March 23, 2016, 03:22:46 PM
Yes, you can. For the time being, you would have to live with THIS, though:
Want me to help with PCB layout?
Quote from: daleykd on March 23, 2016, 03:25:41 PM
Quote from: mfunky on March 23, 2016, 03:22:46 PM
Yes, you can. For the time being, you would have to live with THIS, though:
Want me to help with PCB layout?
I don't think it is necessary, thanks - It is all drawn up in eagle already, minor bugfixes (coding/breadboarding/back to eagle,...). I am planning to make the software open source anyway, once I have mine running (so people can tweak values like maximum delay, default modulation values for zero delay (basically a chorus or a leslie ;-)), colour settings for the multicolor LED, subdivision factors (triplets, dotted eight,...), increase/decrease values for the rotary encoders,... The code is well documented, anybody can tweak it.
Like the idea?
What's the minimum delay you can get with this setup - my guess is that the 'shaky ground' will add substantially to this?
Quote from: mfunky on March 23, 2016, 03:32:45 PM
I don't think it is necessary, thanks - It is all drawn up in eagle already, minor bugfixes (coding/breadboarding/back to eagle,...). I am planning to make the software open source anyway, once I have mine running (so people can tweak values like maximum delay, default modulation values for zero delay (basically a chorus or a leslie ;-)), colour settings for the multicolor LED, subdivision factors (triplets, dotted eight,...), increase/decrease values for the rotary encoders,... The code is well documented, anybody can tweak it.
Like the idea?
Love it!
The thing I was going to try with a PCB layout is to match the same footprint as your arduino and sandwich them together with pin headers. Not sure if that'd help or not. I just
HATE offboard wiring.
Quote from: samhay on March 23, 2016, 03:38:08 PM
What's the minimum delay you can get with this setup - my guess is that the 'shaky ground' will add substantially to this?
I have a physical switch to switch off modulation completely. I don't know how short the delay is with a minimal setting (there is some), but it is not audible (so, way below a slapback). It adds just a bit of "space" to the tone. I will post a video to give you a better idea.
Quote from: daleykd on March 23, 2016, 03:44:44 PM
Quote from: mfunky on March 23, 2016, 03:32:45 PM
I don't think it is necessary, thanks - It is all drawn up in eagle already, minor bugfixes (coding/breadboarding/back to eagle,...). I am planning to make the software open source anyway, once I have mine running (so people can tweak values like maximum delay, default modulation values for zero delay (basically a chorus or a leslie ;-)), colour settings for the multicolor LED, subdivision factors (triplets, dotted eight,...), increase/decrease values for the rotary encoders,... The code is well documented, anybody can tweak it.
Like the idea?
Love it!
The thing I was going to try with a PCB layout is to match the same footprint as your arduino and sandwich them together with pin headers. Not sure if that'd help or not. I just HATE offboard wiring.
I will do it that way - use the arduino nano as shield. With 3 encoders, power supply, up to 5 switches, control out, RGB-LED,... there is still a lot of offboard wiring. Maybe I come back to your offer once I think I am done with the micro-bugfixes. Probably, there should be more than one layout for different use cases anyway...
Great work man, awesome to see your progress :)
This is a great idea. Taptation has been a thorn in my side. I've been thrown off of two forums because I can't get a straight answer about how to make it accurate. Touchy subject for people who sell the stuff I guess. So this project would be a God send!
How much do you have tied up in parts if you don't mind me asking? I don't know what an Arduino costs.
Quote from: blearyeyes on March 24, 2016, 02:35:19 AM
This is a great idea. Taptation has been a thorn in my side. I've been thrown off of two forums because I can't get a straight answer about how to make it accurate. Touchy subject for people who sell the stuff I guess. So this project would be a God send!
How much do you have tied up in parts if you don't mind me asking? I don't know what an Arduino costs.
http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313.TR0.TRC0.H0.Xarduino+nano.TRS0&_nkw=arduino+nano&_sacat=0 (http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313.TR0.TRC0.H0.Xarduino+nano.TRS0&_nkw=arduino+nano&_sacat=0) ;D
Last time I wandered through Arduino land I don't think they had these little guys. Wish I knew more about programming.
Quote from: blearyeyes on March 24, 2016, 02:35:19 AM
This is a great idea. Taptation has been a thorn in my side. I've been thrown off of two forums because I can't get a straight answer about how to make it accurate. Touchy subject for people who sell the stuff I guess. So this project would be a God send!
How much do you have tied up in parts if you don't mind me asking? I don't know what an Arduino costs.
Thanks - I just would like to mention that I dont want to compete with anything out there or endanger somebodys business, I am not planning to get rich on this and I see this simple as an addition to the community, developed for myself, provided to the community. Once I publish the code, I will make it available under creative commons (or similar) license models, so nobody else will get rich on it either. Actually, I doubt that anybody in this diy-community gets rich on these things at all, including all our heroes (madbean and so on). The market is too small for this. We are all just here for fun, right?!
Known drawbacks over existing solutions:
- I guess it will be a bit bigger than e.g. taptation, so it might be tricky to squeeze it in one box together with a given delay.
- In order to make it run, you will have to upload code to an arduino and calibrate it. This should be straightforward, but with some arduinos (china copies), you might have (solvable) driver issues.
- Sourcing some parts may be tricky. I guess that is the reason why I have seen other solutions being sold together with the digital pot (I dont plan to make a business out of this, so I will not offer bundles). See "costs" below...
Costs/Sourcing:
- An Arduino is 5$ (1 required), digital encoders (0-3 required) are 1.50$ (plastic) through 3$ (metall), digital pots (2 required) are 1.50$. Including the PCB the total costs will be comparable or higher to other solutions out there.
- Sourcing some of the parts might be tricky: At least in Germany it is tricky to find a supplier, that does not ask for a minimum quantity (http://rs-online-privat.de/), does not kill the project by shipping costs (mouser) and holds all of the components (so you dont have to order at separate places). Maybe someone can spend some time on the internet and search for appropriate suppliers, this will be outside of the portfolio of our standard suppliers (tayda, smallbear, you-name-it). We would need:
- digital pot MCP41100
- digital pot MCP41010
- maybe a digital pot MCP41050 (instead of the 41100, for dual PT-delays, see my question at the beginning)
- rotary encoders e.g. like this one: https://www.reichelt.de/Drehimpulsgeber/STEC12E07/3/index.html?&ACTION=3&LA=2&ARTICLE=73922&GROUPID=3714&artnr=STEC12E07&SID=10VvODwawQATIAAFMB5Yc8a3f9a9111f0c4ead7b1fc845645e850 (https://www.reichelt.de/Drehimpulsgeber/STEC12E07/3/index.html?&ACTION=3&LA=2&ARTICLE=73922&GROUPID=3714&artnr=STEC12E07&SID=10VvODwawQATIAAFMB5Yc8a3f9a9111f0c4ead7b1fc845645e850)
Quote from: mfunky on March 23, 2016, 04:05:20 PM
Quote from: samhay on March 23, 2016, 03:38:08 PM
What's the minimum delay you can get with this setup - my guess is that the 'shaky ground' will add substantially to this?
I have a physical switch to switch off modulation completely. I don't know how short the delay is with a minimal setting (there is some), but it is not audible (so, way below a slapback). It adds just a bit of "space" to the tone. I will post a video to give you a better idea.
excellent - looks like a cool design
I have finished the first official release this morning, which I have been working on (with major breaks) for about half a year now. I am thrilled! As promised, I share this with the community with this post. I will spend the next days with designing a PCB from this and I would like to share the leftovers with the community as well (once they arrive and have been tested, couple of weeks...). I would therefore kindly ask you guys to not build PCBs from this yet. Everything is licensed under creative commons SA.
Here is the package! Happy easter!
Code and Schematic:
Attached.
I am very interested in this project. Thanks so much for putting this together and offering it to the community. I would love to see more people jump on the Arduino train since there are so many possibilities for some cool projects..this one included.
I bought everything from Mouser minus the Arduino, since I have some already to play with.
For the encoder I found the Bourns PEC12R-3220F-S0024
579-MCP41050-I/P
579-MCP41010-I/P
579-MCP41100-I/P
Hope to have the parts by Saturday and can get something breadboarded out to play with. I have a populated Deep Blue to play with.
Thanks
Cody
Cody - that is very cool! For the beginning, connect the arduino to the input and output of the delay and run the "calibrate" program. Obey the instructions in the beginning of the code. You can use the "read eeprom" program to check everything went fine - your delay times should be stored at eeprom location 5, 10, 15,...and so on.
If you were successful with that, the rest will be easy (I guess). Cant wait for the first implementation outside my house...
Best,
Matthias
Would it be possible to design this board without buying the Arduino board itself and just get the microcontroller? Er, in essence, instead of a shield, create an all-in-one?
Looking at your code, which is super clean by the way and easy to follow. A few questions:
What momentary switches you using? Do you get much miss-punches on them? I notice you are using debounce but do you think something like Bounce2.h library would suite this project better? I have used the library in a few projects I am working on and it seems to really help with miss fires and switch chatter.
This is a simple use of it to send a midi note when button1_pin is held down:
void setup() {
// put your setup code here, to run once:
pinMode(button1_pin, INPUT); // declare pushbutton as input
digitalWrite(button1_pin, HIGH); // Enabling a pull-up resistor
debouncer.attach(button1_pin); // setup the Bounce instance
debouncer.interval(5); // Bounce interval in ms
pinMode(led1_pin, OUTPUT); // declare LED as output
Serial.begin(31250); // Set baud rate for MIDI
MIDI.begin();
}
void loop(){
debouncer.update(); // Update the Bounce instance
int lastButtonState = debouncer.read(); // Get the updated value
if (lastButtonState == HIGH) { // check if the input is HIGH (button released)
digitalWrite(led1_pin, LOW); // turn LED On
MIDI.sendNoteOn(69, 127, 1);
// byte data[] = { 0xF0, 0x7F, 0x00, 0x06, 0x02, 0xF7 };
MIDI.sendSysEx(10, data, true);
} else {
digitalWrite(led2_pin, LOW); // turn LED On
digitalWrite(led1_pin, HIGH); // turn LED Off
}
}
Also wondering if a change state of falling edge would be more consistent on tapbuttonpin with a mechanical switch.
I'm not very competent in this as I am still learning, just want to hear your thoughts.
Cody
Quote from: daleykd on March 24, 2016, 06:01:45 PM
Would it be possible to design this board without buying the Arduino board itself and just get the microcontroller? Er, in essence, instead of a shield, create an all-in-one?
Sure - you would have to do the programming e.g. of an atmega328 in a programmer (e.g. an arduino nano). Get the bootloader on it first, of course. And then build the bits and pieces around it (e.g. reset, if you need one, DC stabilization, buffering,...). There is enough documentation around how to do it. I just wanted to use the nano, because it has an USB port and I WILL change/update the program frequently ;-)
If you build it, share it!
Quote from: daleykd on March 24, 2016, 06:01:45 PM
Would it be possible to design this board without buying the Arduino board itself and just get the microcontroller? Er, in essence, instead of a shield, create an all-in-one?
This is something I was just reading on also.
http://www.instructables.com/id/Honey-I-Shrunk-the-Arduino-Moving-from-Arduino-t/ (http://www.instructables.com/id/Honey-I-Shrunk-the-Arduino-Moving-from-Arduino-t/)
It links a great chart to compare with:
https://en.wikipedia.org/wiki/Atmel_AVR_ATtiny_comparison_chart (https://en.wikipedia.org/wiki/Atmel_AVR_ATtiny_comparison_chart)
Cody
Quote from: selfdestroyer on March 24, 2016, 06:12:30 PM
Looking at your code, which is super clean by the way and easy to follow. A few questions:
What momentary switches you using? Do you get much miss-punches on them? I notice you are using debounce but do you think something like Bounce2.h library would suite this project better? I have used the library in a few projects I am working on and it seems to really help with miss fires and switch chatter.
This is a simple use of it to send a midi note when button1_pin is held down:
void setup() {
// put your setup code here, to run once:
pinMode(button1_pin, INPUT); // declare pushbutton as input
digitalWrite(button1_pin, HIGH); // Enabling a pull-up resistor
debouncer.attach(button1_pin); // setup the Bounce instance
debouncer.interval(5); // Bounce interval in ms
pinMode(led1_pin, OUTPUT); // declare LED as output
Serial.begin(31250); // Set baud rate for MIDI
MIDI.begin();
}
void loop(){
debouncer.update(); // Update the Bounce instance
int lastButtonState = debouncer.read(); // Get the updated value
if (lastButtonState == HIGH) { // check if the input is HIGH (button released)
digitalWrite(led1_pin, LOW); // turn LED On
MIDI.sendNoteOn(69, 127, 1);
// byte data[] = { 0xF0, 0x7F, 0x00, 0x06, 0x02, 0xF7 };
MIDI.sendSysEx(10, data, true);
} else {
digitalWrite(led2_pin, LOW); // turn LED On
digitalWrite(led1_pin, HIGH); // turn LED Off
}
}
Also wondering if a change state of falling edge would be more consistent on tapbuttonpin with a mechanical switch.
I'm not very competent in this as I am still learning, just want to hear your thoughts.
Cody
Cody - you are really going into this, I see - awesome! I reused the debounce routine from my Linda looper (http://www.diystompboxes.com/smfforum/index.php?topic=112106.0), and it does not produce any wrong results even with the cheapest buttons. But probably the code would be easier to read with the lib you mentioned (it looks like, I admit). Does it work with long presses as well? Do it, share it!
And thanks for the compliment on the readability of the code - I always wanted to publish that, so I tried to comment as much as possible.
Quote from: selfdestroyer on March 24, 2016, 06:50:53 PM
Quote from: daleykd on March 24, 2016, 06:01:45 PM
Would it be possible to design this board without buying the Arduino board itself and just get the microcontroller? Er, in essence, instead of a shield, create an all-in-one?
This is something I was just reading on also.
http://www.instructables.com/id/Honey-I-Shrunk-the-Arduino-Moving-from-Arduino-t/ (http://www.instructables.com/id/Honey-I-Shrunk-the-Arduino-Moving-from-Arduino-t/)
It links a great chart to compare with:
https://en.wikipedia.org/wiki/Atmel_AVR_ATtiny_comparison_chart (https://en.wikipedia.org/wiki/Atmel_AVR_ATtiny_comparison_chart)
Cody
Cool! But be aware that there is some tricky bits in my code: I had to modify the multipliers for PWM on the modulation (and RGB LED) pins to prevent audible interference. This messes up some internal timers and has some other side effects (e.g. when you switch on Serial communication, SPI to the MCPs does not work correctly). I learned that pins on the IC are grouped (pin pairs), so when using a more tiny IC (with shift registers), this might become really tricky. Not saying its not possible, but the nano with its smd chip is rather small already, I doubt that you can achive a smaller build with the same amount of pins (I use ALL)...
http://uk-electronic.de/onlineshop/index.php?osCsid=e667159f6be43fc52b5fd9ee08751f34
This looks to be an all around good option for components, almost independent of your location. I have'nt completed an order yet, but I have a cart full that I need to go ahead and close on.
Quote from: TalkingStrings on March 25, 2016, 05:46:24 AM
http://uk-electronic.de/onlineshop/index.php?osCsid=e667159f6be43fc52b5fd9ee08751f34
This looks to be an all around good option for components, almost independent of your location. I have'nt completed an order yet, but I have a cart full that I need to go ahead and close on.
I know Uwe's shop, very reliable, I can recommend him. Did not know he had the digital pots already! Thanks for the hint!
This is really interesting! I still need to get some digital pots so I can look into this :) Great work!
Planning the layout... I will reduce from three preset buttons to one, that can cycle through three user specific presets and an additional multicolor led for the presets. Everything except the 3 foot switches (tap tempo, subdivision, presets) can be pcb mounted. A 10 mm hole will give access to the USB port ;-)
...the nano will most likely have to go on the bottom side, given its height compared to the encoders.
Very very cool! How much storage does the code use up on the Arduino? Like others, I'm wondering about attempting to use an ATtiny chip or a bare uC, but the Arduino Nano looks like it would probably be just as small in the end.
The program uses like 26% of the nano's storage. But a lot of it is for modulation, rotary pot reading and such. I guess it would be possible to strip it down to just tap tempo - one button, one LED, that is all (besides one digital pot, some caps, an oscillator and such). Calibration might be tricky (you would need the connection for the footswitch and the LED while running the calibration program, upload the main program and than connect the footswitch and the LED).
Meanwhile, I am making progress with the PCB. There will be three rotary encoders (left to right: delay, mod freq, mod depth), two multicolor LEDs (left to right: preset, tempo - will change that, as the tap button will be left and the preset button will be right), three buttons (from left to right tap, subdivision, preset). Modulation on/off will be a SPDT somewhere on the left side (or even the rear of the unit) and there will be one TRS-Jack connection for +9V (left or rear), GND and of course pin6-control to my delay. It might be necessary to solder the nano in (rather than socket it), given it's height; it therefore is placed in a way, that the usb-port is accessible from the right (through a 10 mm hole in the enclosure).
The lower picture shows how the PCB will be placed in a landscape 1590B.
I am on vacation for a week and did not bring the breadboard, so I haven't programmed / tested the change from 3 preset buttons to one preset button. It will probably be a (solvable) prorgrammers nightmare to have one button and an RGB-LED (with only blue and red connected,as I ran out of pins) for cycling through and storing presets:
Storing a new setting should work like this: Press the button long: preset led starts blinking. Press the button short (once or twice) to go to the preset location (red, blue, purple(=red and blue)). Press the button long again to save it there (LED stops blinking).
Gotta say, while I don't fully grasp it all. It is cool as hell and I want one!
Quote from: Soup39 on March 26, 2016, 11:40:49 PM
Gotta say, while I don't fully grasp it all. It is cool as hell and I want one!
I will clarify with Brian, if a group buy is ok for him - if yes, I will sell leftovers there...
Even without a breadboard around, I sorted out the one-button-three-presets issue...
https://123d.circuits.io/circuits/1841053-one-button-three-presets
Start simulation (top left corner), press black button short for preset changes, press button long to change into store mode (LED blinks), select store position with short presses, press button long again to store on selected location and change back to preset mode.
:) :) :) :)
Time to order my sample PCBs.
<>
Nice, I etched up a proto PCB that storyboardist made me and just waiting on one of the digital pot ICs from mouser. I got it breadboarded and tests seem to work well. This has been a fun project for sure, so far.
Cody
Great. I hope I get this soldered over the weekend!
Gesendet von iPhone mit Tapatalk
pcb looks awesome man, can't wait to hear more aout your progress :)
...that moment, you clean up your breadboard, because it WORKS!
Awesome!
Thanks - as I am going to build this now, the topic is more a "build report" than a question about how to use this for a dual PT2399 approach (I still would like to know, if this works ;-)). This being said, I started a new thread here:
http://www.madbeanpedals.com/forum/index.php?topic=22653.0