2 layers41.4 × 110.3 mm
Uncertainty
oamodular/uncertainty
This readme needs to be updated to reflect this and to talk about the many other languages that people have used to create new firmware for Uncertainty.
51 parts43
2 layers52.1 × 116.8 mm
DIY Uncertainty
oamodular/uncertainty43This readme needs to be updated to reflect this and to talk about the many other languages that people have used to create new firmware for Uncertainty.
- Size
- 52.1 × 116.8 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 67
- Nets
- 52
- Pads
- 191
- Tracks, vias
- 452, 39
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 7 (file 20221018)
- Created
- 25 Feb 2023
- Updated
- 15 Jan 2026
Overview
DIY Uncertainty is an open-source printed circuit board by oamodular, from the oamodular/uncertainty repository on GitHub. It is a 2-layer board of 52.1 × 116.8 mm with 67 parts on 52 nets, routed with 452 tracks and 39 vias.
It is built around the SN74HCT125DE4 and L7805CV. Its parts include 19 resistors, 11 diodes, 11 connectors, 5 ICs and 1 capacitor. It belongs with the SAM D and SAM boards of this library.
Main components
2
SN74HCT125DE4
SOIC-14-40℃~+85℃ 1 22ns@5.5V,50pF 4 4.5V~5.5V 6mA 6mA 74HCT 80uA Output enable TTL Compatible CMOS Tri-State Unidirectional SOIC-14 Buffers, Drivers, Receivers, Transceivers ROHSTexas InstrumentsBuffers, Drivers, Receivers, Transceivers
L7805CV
TO-2200℃~+125℃@(Tj) 1 1.5A 2V@(1A) 35V 5V 68dB@(120Hz) 8mA Fixed Over Current Protection、Over Temperature Protection、Short Circuit Protection Positive TO-220 Voltage Regulators - Linear, Low Drop Out (LDO) Regulators ROHSSTMicroelectronicsVoltage Regulators - Linear, Low Drop Out (LDO) Regulators
README
README.mdUncertainty is now OSHW! both the software and the hardware!
This readme needs to be updated to reflect this and to talk about the many other languages that people have used to create new firmware for Uncertainty. Right now I just want to say that the 4hp DIY version of Uncertainty is still a work in progress. It's been built, but we're in the process of trying to figure out why it doesn't work. The 2hp SMT version of Uncertainty is the one that we sell here.
What remains below is the previous readme. It contains the pinout for Uncertainty's Seeeduino Xiao RP2040 and some example Python code…
Hack Uncertainty for fun and profit
Uncertainty's firmware is open-source and easy to swap with a humble USB-C cable. You can write your own firmware in C++, MicroPython, CircuitPython, and probably a bunch of other languages. It's startlingly easy to work and this document will outline the whole deal. Let's go…
Uncertainty’s Heart
We’re working with the mighty RP2040, a dual-core 133 MHz arm processor that is just a silly amount of power for outputting gates. Heck, you can easily overclock to over 300 MHz. Really hoping people make some messed up things.
Uncertainty’s I/O
- one CV input that can recognize signals -5v to +5v (resolution is functionally close to 10-bit, so there probably isn’t quite the precision for v/oct)
- eight +5v gate outputs that each have their own LED (if you turn on the gate, you turn on the LED; they can’t be decoupled)
- a three pin I2C connector (this feature is experimental and largely untested)
To access this I/O use the following pins. You can use other pins, but they won’t work. I don’t know why you’d use other pins. Use these pins:
| Pin # | |
|---|---|
| CV input | 26 |
| Gate 1 | 27 |
| Gate 2 | 28 |
| Gate 3 | 29 |
| Gate 4 | 0 |
| Gate 5 | 3 |
| Gate 6 | 4 |
| Gate 7 | 2 |
| Gate 8 | 1 |
| I2C SDA | 6 |
| I2C SCL | 7 |
How to reinstall the default firmware
You hold down the boot button when you plug in the USB-C as described in the Getting started section. Then you drag uncertainty.uf2 onto the RPI-RP2 disk. It should then unmount. All set! The same works for any .uf2 firmware.
Parts
67| Qty | Value | Footprint | References |
|---|---|---|---|
| 10 | PinHeader_1x02_P2.54mm_Vertical | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | XP, XP1, XP2, XP3, XP4, XP5, XP6, XP7, XP8, XP9 |
| 10 | PinSocket_1x02_P2.54mm_Vertical | Connector_PinSocket_2.54mm:PinSocket_1x02_P2.54mm_Vertical | XJ, XJ1, XJ2, XJ3, XJ4, XJ5, XJ6, XJ7, XJ8, XJ9 |
| 9 | AudioJack2 | Import Library:Socket-3.5mm THT-Thonkiconn PJ398SM-12 | J1, J2, J3, J4, J6, J7, J8, J9, J11 |
| 8 | 1K | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R1, R3, R6, R10, R13, R15, R17, R19 |
| 8 | 300 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R2, R4, R9, R11, R12, R14, R16, R18 |
| 8 | LED | Import Library:LED-THT Red Angle130-L-47XEC | D1, D2, D3, D6, D7, D8, D9, D11 |
| 3 | 100K | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R5, R7, R8 |
| 3 | 1N5819 | Diode_THT:D_DO-41_SOD81_P7.62mm_Horizontal | D4, D5, D10 |
| 2 | SN74HCT125DE4 | Import Library:Quad Bus-Tri-State Quad Bus non-inverting THT-SN74HCT125NE4 | U1, U5 |
| 1 | 22uF | Capacitor_THT:CP_Radial_D5.0mm_P2.50mm | C1 |
| 1 | Conn_01x03_Pin | Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical | J5 |
| 1 | L7805CV | Package_TO_SOT_THT:TO-220-3_Horizontal_TabDown | U3 |
| 1 | L78L33ACZTR | Package_TO_SOT_THT:TO-92 | U4 |
| 1 | SeeeduinoXIAO | Import Library:Microcontroller-XIAO RP2040 | U2 |
| 1 | ~ | Import Library:Connector-2x5 2.54p THT-861400102YO9323LF | J10 |
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Questions
How big is the DIY Uncertainty PCB?
It measures 52.1 × 116.8 mm and has 2 copper layers, 1.6 mm thick.
What parts does the DIY Uncertainty use?
67 parts, built around the SN74HCT125DE4 and L7805CV. 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 DIY Uncertainty KiCad files?
From the oamodular/uncertainty repository on GitHub, at the commit this page was made from: the board is hardware/4hp-diy-uncertainty/DIY Uncertainty.kicad_pcb and its schematic hardware/4hp-diy-uncertainty/DIY Plate/DIY Plate.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the DIY Uncertainty design in my own project?
Its repository states no licence, so its author keeps all rights: ask oamodular before reusing the design.