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2 layers62 × 122 mmPedalSHIELD MEGA, the printed circuit board in 3D

PedalSHIELD MEGA

nablum/pedalSHIELD-MEGA

Lo-fi programmable guitar pedal based on pedalSHIELD MEGA by Electrosmash.

Size
62 × 122 mm
Copper layers
2
Thickness
1.6 mm
Parts
38
Nets
66
Pads
155
Tracks, vias
234, 48
Pours
2
Routed
Yes
KiCad
KiCad 8.0 (file 20240108)
Created
20 Sep 2024
Updated
12 Aug 2025

Overview

PedalSHIELD MEGA is an open-source printed circuit board by nablum, from the nablum/pedalSHIELD-MEGA repository on GitHub, published under the MIT licence. It is a 2-layer board of 62 × 122 mm with 38 parts on 66 nets, routed with 234 tracks and 48 vias.

Its parts include 15 resistors, 11 capacitors, 4 switches, 2 connectors and 1 IC. It belongs with the audio and music boards of this library.

README

README.md

logo

License: CC BY-NC License: MIT Platform: Arduino KiCad OpenSCAD

A programmable guitar effects shield for Arduino MEGA, featuring OLED display, true-bypass footswitch, and DSP-ready input/output stages. Based on pedalSHIELD MEGA by ElectroSmash

device

📦 What’s Included

  • ✅ KiCad project: schematic & PCB layout files for the hardware shield
  • ✅ Arduino examples: boost, fuzz, delay, and other DSP sketches
  • ✅ Bill of Materials: CSV file with component list and Mouser links
  • ✅ Documentation: assembly guide, schematic diagrams, signal flow

🛠️ Assembly & Programming

  1. Clone the repository:

    bash
    git clone https://github.com/nablum/pedalSHIELD-MEGA.git
    cd pedalSHIELD-MEGA
  2. Build the PCB with KiCad or order the board from a fab using the provided Gerbers.

  3. Solder the components according to the Assembly Guide.

  4. Upload an effect sketch to your Arduino MEGA using Arduino IDE.

  5. Plug and play:

    • Guitar IN → Input Jack
    • Output → Amp or Audio Interface
    • Power → USB or DC JACK.

🎛️ Example Effects

Each audio effect is implemented in a separate folder under firmware/effects/:

Effect NameDescription
BitCrusherReduces resolution and sample rate for lo-fi textures
ChorusModulates pitch with delay to create a thickening effect
ChorusOrVibratoBlendable chorus and vibrato with adjustable depth
CleanTransparent clean boost (reference circuit)
DistortionHard-clipping distortion effect
EchoSimple digital delay with feedback loop
FuzzSaturated high-gain fuzz effect
MultiEffectsCombination of multiple effects in a single patch
OctaveCrusherBit reduction with added octave-up/down harmonics
OctaverMixes original with octave-down processed signal
ReverbSimulates ambient reverb using delay-based algorithm
TremoloVolume modulation using a low-frequency oscillator
VibratoPitch modulation effect for expressive shimmer

⚙️ Hardware Specs

  • Compatible with Arduino MEGA 2560
  • 128×64 I²C OLED display (SSD1306)
  • True-bypass footswitch with relay
  • Stereo audio jacks with analog preamp/output
  • Powered via 12 V DC (center-negative)

❓ Troubleshooting

  • OLED not lighting up → Double-check I²C wiring and 4.7k pull-up resistors.
  • No audio output → Ensure signal chain is complete and shield is powered.
  • Arduino upload fails → Check USB port, board selection, and serial permissions.

📚 Resources

🤝 Contributing

Contributions are welcome! You can:

  • Submit new audio effects or improvements to existing sketches.
  • Suggest hardware upgrades (e.g. better op-amps, analog filtering).
  • Improve documentation or add new troubleshooting tips.

Please open a pull request against the main branch and follow the coding style of existing files.

📄 License

📬 Contact

Created by @nablum.
For questions or collaboration ideas, feel free to open an issue or reach out directly.

Parts

38
QtyValueFootprintReferences
94.7kpedalSHIELD_MEGA:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_HorizontalR3, R4, R6, R9, R10, R12, R13, R14, R15
56.8npedalSHIELD_MEGA:C_Rect_L7.0mm_W2.5mm_P5.00mmC2, C5, C7, C8, C9
3100kpedalSHIELD_MEGA:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_HorizontalR5, R7, R8
34.7upedalSHIELD_MEGA:CP_Radial_D4.0mm_P1.50mmC3, C6, C10
2100npedalSHIELD_MEGA:C_Rect_L7.0mm_W2.5mm_P5.00mmC1, C11
21MpedalSHIELD_MEGA:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_HorizontalR1, R2
2~pedalSHIELD_MEGA:Jack_6.35mm_Neutrik_NMJ6HCD2_HorizontalJ1, J2
2~pedalSHIELD_MEGA:SW_PUSH_104-0013-EVXSW3, SW4
11M2pedalSHIELD_MEGA:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_HorizontalR11
1270ppedalSHIELD_MEGA:C_Rect_L7.0mm_W2.5mm_P5.00mmC4
1500kpedalSHIELD_MEGA:Potentiometer_Piher_PT-10-H01_HorizontalRV1
1~pedalSHIELD_MEGA:DIP-8_W7.62mm_Socket_LongPadsU1
1~pedalSHIELD_MEGA:SF17020F030221RL015SW1
1~pedalSHIELD_MEGA:LED_D3.0mmD1
1~pedalSHIELD_MEGA:SW_SPDT_ 100SP1T1B1M1QEHSW2
1~pedalSHIELD_MEGA:LCD_OLED_SH1106LCD1
1~pedalSHIELD_MEGA:Arduino_Mega2560_R3_Shield_pedalSHIELD_MEGAA1

The 37 most common of 38 parts.

Questions

How big is the PedalSHIELD MEGA PCB?

It measures 62 × 122 mm and has 2 copper layers, 1.6 mm thick.

What parts does the PedalSHIELD MEGA use?

38 parts. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.

Where can I download the PedalSHIELD MEGA KiCad files?

From the nablum/pedalSHIELD-MEGA repository on GitHub, at the commit this page was made from: the board is hardware/kicad/pedalSHIELD_MEGA.kicad_pcb and its schematic hardware/kicad/pedalSHIELD_MEGA.kicad_sch. PCBKit opens the board in the browser, with nothing to install.

Can I use the PedalSHIELD MEGA design in my own project?

Its repository publishes it under the MIT licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).

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