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TOPIC: How to Build pedalSHIELD in 5 steps.

How to Build pedalSHIELD in 5 steps. 10 months 3 days ago #25

  • JR
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This document explains how to mount the PCB step by step with photographs and additional information. There is an English and Spanish version of it.

There is also a Flickr gallery with high-res photos of each step.
keep it simple
Last Edit: 8 months 2 weeks ago by JR.
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How to Build pedalSHIELD in 5 steps. 8 months 3 weeks ago #49

  • Gallego Arias
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Hi JR, thank you for pedalshield.

The build instructions are very nice and quite easy to follow. I could complete the board without problems. Still waiting for the DUE so I couldn't test the pedal yet.

Some things I've found:
  • The picture of the completed board seems wrong. If you look at the Flickr gallery, U2/U3 seem swapped, right?
  • Some more advice on how to insert the IC would be nice.
  • When soldering the potentiometers and the switches it would be good to warn the user to check their positioning against the plastic cover. If they are not properly aligned the cover will not fit well.

Best!
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How to Build pedalSHIELD in 5 steps. 8 months 3 weeks ago #52

  • Icefire
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Hi JR,

the pedalshield arrived yesterday and today i started soldering. I had thus far one minor problem with a hole on the printboard not being open. With a bit of turning and pushing with a cut-of lead access of a resistor i managed to pinch trough. All other holes seem fine.

One thing questions me now: the diodes (the 4 ones next to each other in your step 2.c) have strange polarity to me (i am a beginner though). The side with the gray circle should be the negative side or cathode (correct?). However in your photo's the diodes-gray-circled-sides are connected to the square holes in stead of the round holes.

Also the former question about the IC's (U2/U3) frightens me a bit.

I'm skipping these parts now and continue the the other parts and hope you can reply on my question soon.

Thanks, and thanks for the great project,

Ysbrand.
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How to Build pedalSHIELD in 5 steps. 8 months 3 weeks ago #53

  • gamoesp
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Ok, as I've got my own pedalSHIELD built and running fine in front of me, I can help you with this:

1. I've checked the Flickr gallery and indeed it's wrong, U2 and U3 are swapped. U1 and U2 are the same chip (TL0721) and U3 is the power supply chip (TC1044)

2. Regarding the diodes, as you say, the circle indicates the cathode of the diode. This pin must be connected to the square pad just as you can see in the photos (they are correct). You can also follow the screening of the PCB, where you can easily see a bold line indicating the cathode.

Hope this helps and you can finish the assembly!
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How to Build pedalSHIELD in 5 steps. 8 months 3 weeks ago #55

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Hi, gamoesp is completely right:
  • The Flickr galery was wrong, I have updated it. (U1=U2=TL072 U3=TC1044)
    The U1/U2/U3 silk screen marks indicate the PIN 1 of the ICs. I have put a red dot to highlight the PIN1 in case of confusion:

    explanation_2014-01-12.jpg

  • When soldering the potentiometers and the switches it would be good to warn the user to check their positioning against the plastic cover. If they are not properly aligned the cover will not fit well.
    You're right, soldering the Pots/Switches like that make them easier to fit with the cover, I have updated it in the document.

  • The grey circle indicates the cathode. Cathode goes to the square pad. Check the photo over these lines. :)
    anodecathode.jpg
Thanks for the feedback!
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keep it simple
Last Edit: 8 months 2 weeks ago by JR.
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How to Build pedalSHIELD in 5 steps. 8 months 3 weeks ago #57

  • Icefire
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Allmost done here.
I had to cut 4 of the pins to have space for the output-jack. I also left out of of the rubber rings on the output jack for this.
The tips to first put the orange cover on to align the switches and pot meters helped well.
One (hopefully) last question: what about the polarity of the led? Does it matter in this case and yes how do i align it? It has a long and a short leg: does the long or the short leg come on the side marked with D5?

You say the jumper on JP1 is optional. What function can it have when soldered?
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How to Build pedalSHIELD in 5 steps. 8 months 3 weeks ago #58

  • JR
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Sometimes I cut 2 pins and sometimes 4, it depends of the lengh of the pin header, and not all the plastic rings of the audio jacks are needed.
what about the polarity of the led? Does it matter in this case and yes how do i align it? It has a long and a short leg: does the long or the short leg come on the side marked with D5?
It matters, in the silk screen you can see the flat side (next to the D5 text) this is the cathode.
This short lead (cathode) goes to the flat side of the diode, like the image below:
IMG_2969.jpg

LEDOutline.gif
You say the jumper on JP1 is optional. What function can it have when soldered?
The jumper 1 basically moves the virtual ground from 1.6V to 0V when it is placed. Doing so, the ADC0 will digitalize the positive part of the guitar signal and the ADC1 will read the negative part of the input signal. Similar to the "Double Span and Digitize Signals Using Two ADCs" (check Fig.2) It works but it is kind of experimental feature, I will prepare a topic to explain how it works in detail.
keep it simple
Last Edit: 8 months 3 weeks ago by JR.
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How to Build pedalSHIELD in 5 steps. 5 months 3 weeks ago #111

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Hi JR,

shortly after your last reply i finished the pedal. My expectations about the sound quality might have been a bit to high but it was fun to do. Thanks for that.

One thing though i want to share with you. The pedal should need a backplate or something to prevent tilting and protect the usb-ports. When applying the switch with your foot the pedal tends to tilt. Because the usb-cable must me connected to power the pedal it gives to much pressure on the usb-port while tilting My port broke of the arduino. I tried to resolder it but it still malfunctions. Luckily this arduino has two usb-ports.


I will make some triplex base where i will fasten my pedal shield on.

For future designs you might want to consider to have the usb connectors on the upper side of the pedalshield instead of on the down side.
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How to Build pedalSHIELD in 5 steps. 5 months 3 weeks ago #112

  • JR
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Thanks for the feedback! :)
I was thinking also about a plexiglas backplate, but placing rubber pads that you can find anywhere the pedal sticks better to anyplace:
IMG_3342.jpg

Regarding the USB port, I miss the USB type B connector which is in Arduino UNO, but I guess that in order to improve the form factor the went for the Micro-B. Some people appraise that it breaks off easily. I have several Ardunio DUE boards and in one asian clone, the port got broken the first day. However, I am very happy with original "italian" Arduino DUE boards build quality.
For future designs you might want to consider to have the usb connectors on the upper side of the pedalshield instead of on the down side.
Thanks for the suggestion!
keep it simple
Last Edit: 5 months 3 weeks ago by JR.
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How to Build pedalSHIELD in 5 steps. 4 months 6 days ago #123

  • Yetzederixx
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I'm on my way to a show where a friend is gonna test this thing out so I don't have a ton of time to search. How long are the plastic tube spacers you used over the connecting bolts?
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