2 layers84.7 × 80.8 mm
2 layers17.4 × 29.9 mm
ESPCord
JudasLilith/ESPCorda power controller powered with the ESP32.
- Size
- 17.4 × 29.9 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 8
- Nets
- 43
- Pads
- 69
- Tracks, vias
- 90, 4
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20260206)
- Created
- 20 Jun 2026
- Updated
- 26 Jun 2026
Overview
ESPCord is an open-source printed circuit board by JudasLilith, from the JudasLilith/ESPCord repository on GitHub, published under the GPL-3.0 licence. It is a 2-layer board of 17.4 × 29.9 mm with 8 parts on 43 nets, routed with 90 tracks and 4 vias.
It is built around the ESP32-C3 and SRD-03VDC-SL-C. Its parts include 2 capacitors, 2 resistors, 2 ICs, 1 connector and 1 switch. It belongs with the ESP32 and RISC-V boards of this library.
Main components
2
ESP32-C3
QFN-32-EP(5x5)12bit 160MHz 22 3V~3.6V Others QFN-32-EP(5x5) Microcontrollers (MCU/MPU/SOC) ROHSEspressif SystemsMicrocontrollers (MCU/MPU/SOC)
SRD-03VDC-SL-C
插件,19.2x15.6mm100mΩ 10ms 10ms 15A 250V@AC 360mW 3V 5 Non-Polarized - Single Coil One set changeover: 1C (SPDT - changeover) 插件,19.2x15.6mm Power Relays ROHS松乐Power Relays
README
README.mdESPCord
- An ESP32-based PCB to connect to Wall adapters for controlling power to SBCs.
Why make this?
-
I normally use a small Raspberry Pi Zero in order for me to control my Octoprint setup, but due to the board being connected constantly it cannot shut down with the normal octoprint UI. This is when I thought that I should have a method of controlling the power going to the Setup, so that it can properly reboot every time I manipulate its power source by being connected to Home Assistant.
-
Don't you have wall plugs that do this?
- You're absolutely right! however:
- The prices are at least 30 dollars a pop
- most of the cheaper ones want you to use their own crummy software
- It's closed source(yuck!)
- most of them connect to wall sockets, so if you move between countries where one uses 110 and the other uses 220, it's better to just connect from the wall adapter itself(since you know that the voltage coming from there is a regulated 5v.)
- You're absolutely right! however:
Images
How to Make one:
WARNING! The USB and the actual power supply coming from the wires are synonymous, so I do not recommend connecting the Power pins and the USB to flash the program at the same time.
-
The step files for the cover are in hardware/STEP. For each of the PCB's models, it's inside /hardware/ESPCord/JLCImport.3dshapes/.
-
Go to OnShape for the source files: Link to Document
BOM:
For the Detailed version with comments, look at the BOM.csv
| Reference | Qty | Value | Price | Footprint |
| C1,C2 | 2 | 10uF_0805_16V_lowESR | 0.091 | PCM_4ms_Capacitor:C_0805 |
| J1 | 1 | USB_C_Receptacle | 0.05 | PCM_SparkFun-Connector:USB-C_16 |
| K1 | 1 | SRD-03VDC-SL-C | 0.41 | JLCImport:SRD-03VDC-SL-C |
| R3,R4 | 2 | 5.1K | 0.02 | PCM_fab:R_1206 |
| U1 | 1 | ESP32-C3 | 1.83 | PCM_fab:QFN-32_EP_5x5_Pitch0.5mm |
| U2 | 1 | AMS1117-3_3_C347222 | 0.01 | PCM_Package_TO_SOT_SMD_AKL:SOT-223-5 |
| 0 | ||||
| 4 | M3 Bolts 10mm | 19.99 | N/A | |
| 2 | M2 Bolts 25mm | 0 | N/A | |
| 4 | M3 Nuts | 0 | N/A | |
| 2 | m2 Nuts | 0 | N/A | |
| Total: | 22.351 |
Total: 22.351 - The case has around 12 grams of PLA, so it's most likely negligible.
For the design checker: I already have a kit with M2-M3 bolts and nuts, so the amazon kit will be redundant in my case. I just wantd to show where other people could source the parts in bulk.
Assembly:
Whole Model:
Next Steps:
-
Time to actually connect the relay with the power cables now.
-
Now all you need to do is:
- Split the cable in half
- Find the Red and Black wires, then solder them onto each pads with the Label GND and VIN.
- Be sure that the nuts do not touch, if using bare metal nuts and bolts.
-
Great job following along! now you must flash the ESP with ESPHome. (You can find more information at: https://esphome.io/guides/getting_started_hassio/)
-
I tried to make a simple configuration file in /firmware, but it's not tested yet so take it with a grain of salt please :3
Parts
8| Qty | Value | Footprint | References |
|---|---|---|---|
| 2 | 10uF_0805_16V_lowESR | PCM_4ms_Capacitor:C_0805 | C1, C2 |
| 2 | 5.1K | PCM_fab:R_1206 | R3, R4 |
| 1 | AMS1117-3_3_C347222 | PCM_Package_TO_SOT_SMD_AKL:SOT-223-5 | U2 |
| 1 | ESP32-C3 | PCM_fab:QFN-32_EP_5x5_Pitch0.5mm | U1 |
| 1 | SRD-03VDC-SL-C | JLCImport:SRD-03VDC-SL-C | K1 |
| 1 | USB_C_Receptacle | PCM_SparkFun-Connector:USB-C_16 | J1 |
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Questions
How big is the ESPCord PCB?
It measures 17.4 × 29.9 mm and has 2 copper layers, 1.6 mm thick.
What parts does the ESPCord use?
8 parts, built around the ESP32-C3 and SRD-03VDC-SL-C. 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 ESPCord KiCad files?
From the JudasLilith/ESPCord repository on GitHub, at the commit this page was made from: the board is hardware/ESPCord/ESPCord.kicad_pcb and its schematic hardware/ESPCord/ESPCord.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the ESPCord design in my own project?
Its repository publishes it under the GPL-3.0 licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).