2 layers30 × 88 mm
4 layers85 × 88 mm
EmonPi3
openenergymonitor/emon323emonPi3 & emonTx6 Hardware
- Size
- 85 × 88 mm
- Copper layers
- 4
- Thickness
- 1.6 mm
- Parts
- 174
- Nets
- 135
- Pads
- 590
- Tracks, vias
- 933, 260
- Pours
- 565
- Routed
- Yes
- KiCad
- KiCad 7 (file 20221018)
- Created
- 2 Nov 2022
- Updated
- 11 Aug 2026
Overview
EmonPi3 is an open-source printed circuit board by openenergymonitor, from the openenergymonitor/emon32 repository on GitHub, published under the CC-BY-SA-4.0 licence. It is a 4-layer board of 85 × 88 mm with 174 parts on 135 nets, routed with 933 tracks and 260 vias.
It is built around the ATSAMD21J17A-MU, 24FC08T-I/OT and AP2112K-3.3TRG1, with the USBLC6-2P6, DF2B7AE,H3F and SJ-3524-SMT-TR among its other parts. Its parts include 62 resistors, 40 capacitors, 15 diodes, 14 connectors and 7 ICs. It belongs with the SAM D and SAM boards of this library.
Main components
9
ATSAMD21J17A-MU
QFN-64-EP(9x9)QFN-64-EP(9x9) Microcontrollers (MCU/MPU/SOC) ROHSMicrochip TechnologyMicrocontrollers (MCU/MPU/SOC)
24FC08T-I/OT
SOT-23-5-40℃~+85℃ 1,000,000 cycles 1.7V~5.5V 1MHz 200 Years 5ms 8Kbit Hardware write protection function、Noise suppression function I2C SOT-23-5 EEPROM ROHSMicrochip TechnologyEEPROMAP2112K-3.3TRG1
SOT-25-5-40℃~+85℃@(Ta) 1 250mV@(600mA) 3.3V 50uVrms 55uA 600mA 65dB@(1kHz) 6V Fixed Over Current Protection、Thermal Shutdown、Enable control Positive SOT-25-5 Voltage Regulators - Linear, Low Drop Out (LDO) Regulators ROHSDiodes IncorporatedVoltage Regulators - Linear, Low Drop Out (LDO) Regulators
USBLC6-2P6
SOT-666-6-40℃~+125℃ 150nA 17V 2 3.5pF 5.25V 5A@8/20us 6V ESD IEC 61000-4-2 Unidirectional SOT-666-6 ESD and Surge Protection (TVS/ESD) ROHSSTMicroelectronicsESD And Surge Protection (TVS/ESD)
DF2B7AE,H3F
SC-79(SOD-523)100nA 20V 4A@8/20us 5.5V 6.8V 8.5pF 80W@8/20us Bidirectional IEC 61000-4-2 TVS SC-79(SOD-523) ESD and Surge Protection (TVS/ESD) ROHSToshibaESD And Surge Protection (TVS/ESD)
SJ-3524-SMT-TR
SMDSMD Audio Connectors ROHSCUIAudio Connectors (Headphones)
MPZ1608D300BTA00
0603-55℃~+125℃ 1 1.8A 30Ω@100MHz 60mΩ ±25% 0603 Ferrite Beads ROHSTDKFerrite Beads
LTST-S326KGJRKT
SMD,3x2mm-30℃~+85℃ 130° 20mA 2V、2V 35mcd、45mcd 571nm、631nm 574nm、639nm 75mW Common Anode Red, Yellow Green Side View Mount Water Clear SMD,3x2mm LED Indication - Discrete ROHSLite-OnLED Indication - Discrete
54602-908LF
插件-40℃~+70℃ 1 12.7mm 15.3mm 17.74mm Copper Alloy Gold Harpoon Contact (Plastic) Non-LED Non-PoE RJ45 Jack Right Angle Unshielded cat3 Plugin Ethernet Connectors / Modular Connectors (RJ45 RJ11) ROHSAmphenolEthernet Connectors / Modular Connectors (RJ45 RJ11)
README
pcb/emonpi3/README.mdemonPi3
emonPi3 is a drop in replacement for the emonPi2. The main change is the use of a modern high performance microcontroller in place of the aging and expensive AVR parts. Additionally, the firmware moves away from using Arduino as the base environment.
Firmware
Firmware for the emonPi3 is available here. The emonPi3 comes preloaded with a USB bootloader, allowing the firmware to be updated without any specialised hardware.
Generating manufacturing outputs
You will need to have KiCad 7 installed. In the emonpi3 folder, run python3 generate.py. This will make a folder called output-<gitrev> with the following contents:
- KiCad schematic annotated with git revision
- KiCad PCB annotated with git revision
- Schematic PDF
- Floorplan PDF
- Bill of materials CSV
- Gerbers output
- 3D render (STEP format)
This has been tested on Linux and macOS.
Changelog
1.0
Production
- Correct front panel LED footprint
- Routing tweaks
0.2
First production candidate
- Correct SPI connection
- Move LED to front panel
- ESD protection on all inputs and buttons
- Expose reset to Pi connection
0.1
First public limited manufacturing run.
- Add hardware zero crossing detector.
- Add ADC calibration hardware.
- Add more testpoints.
- Move EEPROM and reassign serial modules.
- Add user button, LEDs, and external I2C header.
0.1-dev
- First bring up of the emonPi3.
- Directly physically compatible with the existing emonPi2.
- Change to 4-layer board
- Add extra filters and power protection
Parts
174| Qty | Value | Footprint | References |
|---|---|---|---|
| 19 | 47K | Resistor_SMD:R_0603_1608Metric | R3, R10, R11, R12, R13, R16, R17, R20, R21, R25, R26, R33, R34, R35, R36, R37 +3 |
| 13 | 10uF | Capacitor_SMD:C_0603_1608Metric | C1, C3, C4, C6, C8, C9, C13, C15, C19, C20, C21, C29, C38 |
| 13 | 3K0 | Resistor_SMD:R_0603_1608Metric | R5, R14, R18, R22, R23, R27, R32, R39, R40, R41, R51, R66, R67 |
| 13 | TestPoint | TestPoint:TestPoint_Pad_D1.0mm | TP1, TP2, TP3, TP4, TP5, TP6, TP7, TP8, TP9, TP10, TP11, TP12, TP13 |
| 10 | 10n | Capacitor_SMD:C_0603_1608Metric | C5, C7, C11, C12, C14, C16, C22, C23, C24, C32 |
| 9 | 5V | Diode_SMD:D_SOD-523 | D1, D2, D3, D4, D5, D6, D7, D8, D9 |
| 8 | 100nF | Capacitor_SMD:C_0603_1608Metric | C27, C31, C33, C34, C36, C37, C40, C41 |
| 7 | 1K | Resistor_SMD:R_0603_1608Metric | R7, R44, R46, R47, R48, R49, R54 |
| 6 | 10K | Resistor_SMD:R_0603_1608Metric | R8, R9, R45, R55, R56, R57 |
| 6 | 5K1 | Resistor_SMD:R_0603_1608Metric | R28, R29, R30, R31, R42, R43 |
| 6 | 6R8 | Resistor_SMD:R_1206_3216Metric | R1, R2, R6, R15, R19, R24 |
| 6 | SJ-3524-SMT-TR | Connector_Audio:Jack_3.5mm_CUI_SJ-3524-SMT_Horizontal | J1, J2, J3, J4, J5, J6 |
| 6 | SolderJumper_2_Open | Jumper:SolderJumper-2_P1.3mm_Open_TrianglePad1.0x1.5mm | JP1, JP2, JP3, JP4, JP5, JP6 |
| 5 | 1uF | Capacitor_SMD:C_0603_1608Metric | C25, C26, C28, C30, C35 |
| 5 | 22R | Resistor_SMD:R_0603_1608Metric | R59, R60, R61, R62, R70 |
| 5 | ESD5Z3.3T5G | Diode_SMD:D_SOD-523 | D10, D11, D12, D13, D15 |
| 4 | 1n | Capacitor_SMD:C_0603_1608Metric | C2, C10, C17, C18 |
| 4 | MountingHole | MountingHole:MountingHole_2.7mm_M2.5 | H1, H2, H3, H4 |
| 3 | FIDUCIAL1X2 | Fiducial:Fiducial_0.75mm_Mask1.5mm | FD1, FD2, FD3 |
| 2 | CONN_04PTH | Connector_PinSocket_2.54mm:PinSocket_1x04_P2.54mm_Vertical | J7, J8 |
| 2 | FerriteBead | Resistor_SMD:R_0603_1608Metric | FB1, FB2 |
| 1 | 24FC08-OT | Package_TO_SOT_SMD:SOT-23-5 | U8 |
| 1 | AP2112K-3.3 | Package_TO_SOT_SMD:SOT-23-5 | U4 |
| 1 | ATSAMD21J17A-M | Package_DFN_QFN:QFN-64-1EP_9x9mm_P0.5mm_EP4.7x4.7mm | U3 |
| 1 | CONN_03SCREW | TerminalBlock_Phoenix:TerminalBlock_Phoenix_PT-1,5-3-3.5-H_1x03_P3.50mm_Horizontal | CN3 |
| 1 | Conn_02x05_Odd_Even | Connector_PinSocket_2.54mm:PinSocket_2x05_P2.54mm_Vertical | J13 |
| 1 | Conn_02x20_Odd_Even | RPi-SMD:REF-182665 | J12 |
| 1 | Conn_ARM_JTAG_SWD_10 | Connector_PinHeader_1.27mm:PinHeader_2x05_P1.27mm_Vertical_SMD | J10 |
| 1 | LED_Dual_KAK | ltst-s326:LTST-S326 | LED5 |
| 1 | MCP1501T-10E/CHY | Package_TO_SOT_SMD:SOT-23-6 | U1 |
| 1 | MountingHole | MountingHole:MountingHole_2.1mm | H7 |
| 1 | RFM69CW | rfm69cw:RFM69CW | U7 |
| 1 | RJ45-8PTH | Connector_RJ:RJ45_Amphenol_54602-x08_Horizontal | RJ1 |
| 1 | SMACONNECTOR | Connector_Coaxial:SMA_Amphenol_132203-12_Horizontal | SMA1 |
| 1 | SOLDERJUMPERNC | Jumper:SolderJumper-2_P1.3mm_Open_TrianglePad1.0x1.5mm | GND_LINK1 |
| 1 | SW_Push | Button_Switch_THT:SW_PUSH_6mm | SW1 |
| 1 | SW_Push | Button_Switch_SMD:SW_Tactile_SPST_NO_Straight_CK_PTS636Sx25SMTRLFS | SW3 |
| 1 | Screw_Terminal_01x06 | TerminalBlock_Phoenix:TerminalBlock_Phoenix_PT-1,5-6-3.5-H_1x06_P3.50mm_Horizontal | CN1 |
| 1 | TPS2116DRLR | Package_TO_SOT_SMD:SOT-583-8 | U5 |
| 1 | USBLC6-2P6 | Package_TO_SOT_SMD:SOT-666 | U2 |
| 1 | USB_C_Receptacle_USB2.0 | valcon-usb:CSP-USC16-TR | J9 |
The 172 most common of 174 parts.
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Questions
How big is the EmonPi3 PCB?
It measures 85 × 88 mm and has 4 copper layers, 1.6 mm thick.
What parts does the EmonPi3 use?
174 parts, built around the ATSAMD21J17A-MU, 24FC08T-I/OT, AP2112K-3.3TRG1 and USBLC6-2P6. 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 EmonPi3 KiCad files?
From the openenergymonitor/emon32 repository on GitHub, at the commit this page was made from: the board is pcb/emonpi3/emonPi3.kicad_pcb and its schematic pcb/6ct-expander/6ct-expander.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the EmonPi3 design in my own project?
Its repository publishes it under the CC-BY-SA-4.0 licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).