Schematic to breadboard layout


Good to hear you got your connection stable, if things stop working in future (especially if you haven’t made circuit changes) remember that it could be that connection getting flaky again. If possible keep the small circuit you used to test it around so you can verify it is still working in future and your problem hasn’t come back as it can save frustrating hours searching for a problem that isn’t in your circuit but in that connection :slight_smile: . As to breadboards, yep looks like you have one of the half (around 400 pin against 800 for the one in breadboard) breadboards. You’ll need at least a full size one to get just the buttons and leds you currently have in your first circuit on to it. You may want to get something like this (most local places will have them) or just some 22 or 24 gauge solid insulated wire and cut and strip your own to make smaller jumpers at least for things like the ground connections. The flexable wires with pins that you look to be using are good for longer connections or ones that you want to change often but they get crowded fast when there are many connections. Wires right down on the base of the breadboard will give you room to actually push the switches which looks somewhat difficult right now :slight_smile:



I’m going to buy some smaller wires like you suggested and a larger motherboard. Happy things are starting to take off now and slowly getting somewhere. I’m going to build the full circuit of the completed version you did. Think I will need help with where to place the LED’s but I will have a go with wiring it on fritzing first like you said earlier on. I’m going to end up making it more complicated. Because I need them to light up red or green depending on what mode the pedal is in. But someone has sent me an example of how to do that on another forum. So that could be interesting, also on the same forum Somone suggested to use a electroluminescent panel for the Chewie II logo.


As long as you only want one (or a small number of them) something like this from one of my favorite surplus places may do. You need to watch the shipping on it as US postal rates are pretty high but they have some neat stuff, it tends to sell out quickly (at least sometimes) and then be no longer available and data on how to hook it up is often either non existent or sketchy. (although this particular one looks pretty easy) :

Ebay is another potential source although I didn’t see anything that good in a quick search. If the logo isn’t changing a panel will be cheaper and easier to hook up than any of the displays.



Just thought I won’t be able to use one because I need it to change colour. It stays green. But when I pedal is pressed it flashes red. Don’t know how I’ll do it now.


Then you need to get creative :slight_smile: some options:

For what you need (2 colors, fixed text) the best alternative would be a piece of while plexiglass panel with 2 color red/green leds behind it to light it up and diffuse the light to illuminate a logo printed on transparent laser paper (such as overhead foils are made from) glued to the top of the plexi. It may be a bit hard to get the color even across the sheet, but you may not care or even like the effect. The more complex solution would be to use a color display with the logo displayed as a graphic on the display. This (if you don’t need a size larger than 1.4 inches) is the cheapest I see but will likely be poorly documented (although it does have a download button for a library and I know of an Arduino library for these on the net).
If you need bigger it has larger more expensive cousins but interfacing them can be difficult to impossible. I’d try the led/plexiglass/bicolor led method first to see if you can get something acceptable. (despite the “Red” in the description which I think applies to the pcb :slight_smile: this appears to be a full color display)



For the logo I was thinking of having it laser cut out of the housing. Then maybe put a layer of plastic behind it. Maybe frosted. Then have either LED’s or a panel but I’m going to be limited because I need the logo to light up red and green.


If you mean the characters in the logo (as opposed to the background behind the logo) turn from red to green, then you need one of the tft type display panels. The nokia 5150 (single color) lcd driver has a graphics library that can display graphics, I expect the library for the color display listed does the same (although you should check that before buying one :slight_smile: ) if not it is possible but more complex to write a bit map in to the controller to form the logo. As the logo is a graphic being displayed on the panel, it can be changed (with varying amounts of difficulty and brightness) from red to green. Brightness may be an issue as well, leds would be brighter than the tft display. You would have to experiment to see what works for you (and what works in your Arduino, you may have to upgrade the processor to a mega or an arm to get enough memory and I/O pins to do what you need).

(edit: ) Note that most of the tft displays are 3.3V and thus need level translators to run from a 5V Arduino (and you will likely blow up the display if you don’t use the level translators) so if you decide to go this route ask about level translators before doing the hookup.



This is where it’s going to get really complicated. Hope I manage to pull this off with everyone’s help. It’s looking like a tft display because it’s going to be behind the lettering. As I hope to have the lettering cut out of the metal case. If you watch the first few seconds of this video you will see how I want the logo to light up.


The video isn’t available here, but you can cut the project in to smaller chunks (which may be individually complex) such as make a test breadboard of only the tft display and get the logo working then integrate that code and hardware (mostly I/O ports) in to the other sections of the project. Doing that lets you deal with one problem at a time such as getting the display running with text output to debug the interfacing, then change to graphics mode (once you know the hardware is working) to get the logo to the display either via the library or a bitmap and then evaluate whether the result is bright enough for what you need. With a display panel you may not want to have metal in front of it as there will be viewing angle issues probably. I’d mount the screen to the front panel. If you cut the logo out of the front panel your better and easier solution would likely be a piece of plexiglass illuminated by leds. You may have to try both and see which works better.



Yeah that’s a good idea. Think I will do that. Just been researching on how to put the LCD screens in that need to mirror the computer screen. And they are too LCD panels. Don’t have a clue how I’m going to manage to pull this off. I know with two screen you have to write code to be able to use two screens.


You likely won’t be able to do this with an Arduino, they typically don’t have enough memory and processing power to drive a screen like that (plus this particular one doesn’t have any interface that an Arduino can use). You are up in the range of a raspberry PI (perhaps a zero which is cheap if hard to get) but which runs linux What do you need to put on that screen just text or graphics as well? Where is the data for that screen coming from (as its possible it can be driven by whatever produces the data)?



Ah right didn’t see that it wasn’t for arduino. It’s a little hard to explain but I basically need the screens to show what my mac screen is showing. Like when you connect a vga/hdmi cable to mirror it onto another screen like a tv. I need them to do that. Both will be showing the same program but different sections. I’ll be using ableton live with a plugin called mobius. So the screen on the left will show the current tracks sound waves and the screen on the right will show each track being recorded/playing. Sorry if you don’t understand me. Just a little hard to show you. I could show you through this video a little I guess but this loop pedal only has one screen and it’s the guy who posted a tutorial on instructables (he drew the original schematic). His video is here Here is the YouTube video I was trying to show you of ed Sheerans actual loop pedal in action


Then that screen is perhaps what you want, but it will be driven by the Mac not the Arduino (and thus the lack of an Arduino interface doesn’t matter). You will need something like an hdmi cable to that screen from the Mac to get the data there (I don’t know Macs so can’t tell you how to do that or if you can). The second video shows the screen(s) as displaying what looks like an audio level graph (like a VU meter) apparently on 4 tft type screens (which an Arduino may not have enough code space/ processor power to drive) which may be possible on an Arduino, but you then have to get the level data from somewhere in to the Arduino to display.


Alright, how would I power them like power the whole thing once connected? Can’t get my head around it all. Like a mains plug or something? Don’t know how I’m going to get both screens to work. Because I think the program on the mac has to be split. Going to start getting tricky now ain’t it.


Been researching these LCD panels, they seem to come with a USB power in cable. Though it says it’s for raspberry pi I don’t think it would matter. I’m guessing it’s just finding how to connect the power into the screen to the whole circuit? But I wouldn’t know how to do that. Think I make sense?


It got tricky quite a while ago :slight_smile: The initial project was easy enough, it has well defined inputs and outputs and is a suitable size and complexity for an Arduino. Even the addition of the neopixels isn’t too bad (most of the complexity there is in the hardware and Adafruit provided library other than the power issues) and is still suited to an Arduino. Once you get in to tft screens things start to get complex in terms of input data and drive and you start maybe getting beyond the capabilities of a 328 (as in the Uno). By and large power is the easy part of this, a wall wart will usually supply suitable power (it gets more tricky with high current things like neopixels, but screens aren’t a particular power problem). Your current issue is figuring out where the data that is going to appear on the screen comes from, if from the Mac, how does it get to the Arduino? Is it in a format that can be displayed or does the Arduino need to modify it (memory is then likely a problem)? Can it get there fast enough to meet the performance requirements of the various screens? Is there something on the Mac that will generate the data (I’d expect the Mac side to be the most difficult to make changes in but may be wrong)? The audio level data that appeared to being displayed on the screen needs to come from somewhere as it isn’t in the Arduino at the moment. Most of the screens take either 5V or 3.3V for power just like the Arduino. They can probably (although the Arduino 3.3V supply is limited to about 30 ma of current) be powered from the 5V or 3.3V supplies on the Arduino. At worst a coax power jack and a 5V and/or 3.3V wall wart will get you your power. The hard part is going to be getting the data I expect.



I’m going to have to buy a mega going to run out of pins. Going to keep doing research about the screens. I’ll contact the guy who made the original loop pedal with just one screen in it. I have another question, once I have finished testing on breadboard should I put it onto pcb? Because I will be using pedals like these I’ll have to cut the jack off then what cables will that leave me with? 3 wires positive, negative and something else? Sorry I don’t know. This is the screen that was used in the tutorial


Running out of pins isn’t necessarily a reason to buy a mega. There are ways to expand pin count. Running out of code space or ram would be the usual driver towards a mega (and may well be the case here). That said at least on ebay megas aren’t that much more expensive than a Uno

Depemds. If you are making only one of these it probably isn’t worth it. You can use perfboard (which is what I usually do as I’m usually only making one for me) at much less hassle and expense than cutting a pcb. If you want to make hundreds then a pcb makes sense for only one perfboard is probably a better bet. Breadboard view supports various forms of perfboard so you can document what you have done

First, I wouldn’t cut the wires off. They look to be standard 1/4 phone jacks just get an appropriate socket and wire to it leaving the petal intact so it can be reused if this doesn’t work out. You do however need to figure out what the various wires do to know how to connect them. I assume this is intended to replace the pushbutton switches on the breadboard so two of the wires will be the switch contacts but you will need to figure out how that relates to the wires on the plug somehow and what the polarity switch they refer to does (none of which I know, nor does it appear on the amazon web page that I can see).

Still won’t be driven from the Arduino, it is hdmi or VGA neither of which the Arduino supports. You still need to figure out where the screen is driven from (as I said I suspect that is from the Mac not the Arduino) and how to arrange that. I don’t know either of those.



Yeah it’s to replace the push buttons to the pedals for the final version. You mean get a dc jack adapter and connect it like this? I’m not sure how the guy connected them on the tutorial. Think I might have to get in contact with him. Yeah it’ll be from the mac I’m guessing since it’s mirroring it. I just don’t know how he connected his screen. He drew the schematic but it doesn’t show it linked. Just shows it online with the 5V


No I actually mean something like this, (I found the actual pedal manufacturer’s web site and it is a mono 1/4 inch phone jack as it appeared to be in the picture).

If you have a local electronic parts supplier they may have these as singles. There appear to be only two wires from the pedal so I don’t know what the polarity switch does but it should just connect in place of the current push buttons one way or the other I expect. With these the jack on the pedal plugs in to this and you solder wires to the tabs and connect the wires to the breadboard or perf board leaving the pedal unmodified. Cutting the wires and connecting them in place of the current push buttons should also work as far as I can see, it just damages the pedal for any other use. For the screen I suspect it is off an hdmi splitter of some kind, but I don’t know enough about either Macs or Midi to give you a good guess of how to do it. That does make the Arduino part of things a lot easier though :slight_smile: .