2 layers21.7 × 10 mm
Sensor Unit
Dooganar/engg3800-t3-eaar-pcb-design
A repo used to track and collaborate on the pcb design for the University of Queensland "Team Project II" course.
164 parts
2 layers92.4 × 51 mm
Phrog mainboard
Phalkon-Industries/phrogSuper low cost spectrophotometric ph sensor
- Size
- 92.4 × 51 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 41
- Nets
- 46
- Pads
- 131
- Tracks, vias
- 179, 65
- Pours
- 1
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20260206)
- Created
- 19 Aug 2026
- Updated
- 6 Oct 2026
Overview
Phrog mainboard is an open-source printed circuit board by Phalkon-Industries, from the Phalkon-Industries/phrog repository on GitHub, published under the CERN-OHL-S-2.0 licence. It is a 2-layer board of 92.4 × 51 mm with 41 parts on 46 nets, routed with 179 tracks and 65 vias.
It is built around the LM358 and NAU7802KGI. Its parts include 9 resistors, 6 capacitors, 4 ICs, 4 diodes and 2 transistors. It belongs with the sensors and measurement and computers and single-board computers boards and the nRF52 and nRF5x boards of this library.
Main components
2
LM358
SOP-8-18V~18V 0℃~+70℃ 1.2MHz 10nA 2 24mA 3V~36V 500uA 50nA 5mV 80dB Built-in compensation SOP-8 Operational Amplifier ROHSMSKSEMIOperational Amplifier
NAU7802KGI
PDIP-16-40℃~+85℃ 2 2.7V~5.5V 24 80Hz Built-in temperature sensor、Multiplexers、Power-on reset I2C PDIP-16 Analog to Digital Converters (ADC) ROHSNuvoton TechAnalog To Digital Converters (ADC)
README
README.mdphrog
Super low cost spectrophotometric ph sensor
What is the purpose of the pHrog?
To be an educational kit that people can build themselves and use to learn how to make a spectrophotometric measurement.
It should be able to do basic spectrophotometric measuremtns and be able to get pH to +-0.1 units. That is the goal.
It should be easy to build, and be repairable.
Still under early development
Repository layout
| Folder | Contents |
|---|---|
phrog-mainboard/ | KiCad project, datasheets, and production outputs for the mainboard. |
enclosure/ | FreeCAD enclosure model. |
firmware/ | PlatformIO firmware for the nRF52840 Pro Micro (see firmware/README.md). |
License
This project is licensed under the CERN Open Hardware Licence Version 2 - Strongly Reciprocal
(CERN-OHL-S-2.0). See LICENSE for the full text.
Source Location: https://github.com/Phalkon-Industries/phrog
Parts
41| Qty | Value | Footprint | References |
|---|---|---|---|
| 5 | 10k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R1, R2, R6, R10, R12 |
| 3 | 100nF | Capacitor_THT:C_Disc_D4.3mm_W1.9mm_P5.00mm | C1, C2, C6 |
| 2 | 10uF | Capacitor_THT:C_Disc_D4.3mm_W1.9mm_P5.00mm | C4, C5 |
| 2 | 1N5817 | Diode_THT:D_DO-41_SOD81_P10.16mm_Horizontal | D1, D4 |
| 2 | 27R | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R8, R9 |
| 2 | 2N3904 | Package_TO_SOT_THT:TO-92_Inline | Q3, Q4 |
| 2 | 5.6k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R11, R13 |
| 2 | LOGO | LOGO | G***, G*** |
| 2 | Photodiode | -project:PD_Vertical | PD_Blue1, PD_Green1 |
| 1 | 100k | Potentiometer_THT:Potentiometer_Bourns_3296W_Vertical | RV1 |
| 1 | 1M | Potentiometer_THT:Potentiometer_Bourns_3296W_Vertical | RV2 |
| 1 | 1uF | Capacitor_THT:C_Disc_D4.3mm_W1.9mm_P5.00mm | C3 |
| 1 | 7660S | Package_DIP:DIP-8_W7.62mm_LongPads | U4 |
| 1 | BLUELED | LED_THT:LED_D5.0mm_Horizontal_O1.27mm_Z3.0mm | D3 |
| 1 | Battery | Connector_JST:JST_PH_B2B-PH-K_1x02_P2.00mm_Vertical | J1 |
| 1 | GREENLED | LED_THT:LED_D5.0mm_Horizontal_O1.27mm_Z3.0mm | D2 |
| 1 | LM358 | Package_DIP:DIP-8_W7.62mm_LongPads | U2 |
| 1 | NAU7802KGI | Package_DIP:DIP-16_W7.62mm_LongPads | U3 |
| 1 | NRF52840 Pro Micro | -project:nrf52840_pro_micro | U1 |
| 1 | RESET | Button_Switch_THT:SW_PUSH_6mm | SW1 |
| 1 | SW_SPDT | Button_Switch_THT:SW_Slide-03_Wuerth-WS-SLTV_10x2.5x6.4_P2.54mm | SW3 |
| 1 | SampleThermistor | -project:Thermistor_Wire | TH1 |
The 35 most common of 41 parts.
Similar boards
- 2 layers132.1 × 45.7 mm
IPoS
peterheinrich/InternetOverSpaghetti
Transmitting IP packages over a pair of spaghetti thus demonstrating how media independent IP really is.
42 parts342 - 2 layers68.8 × 53.6 mm
ZArduino
zmaker/arduino_cookbook
gli sketch del nuovo progetto Arduino Cookbook e dei video di YouTube
46 parts269 - 2 layers152 × 88 mm
RFBitBangSMT
profdc9/RFBitBanger
A QRP digital transceiver created from readily available parts for off-the-grid maintenance
271 parts222 - 2 layers118 × 103.5 mm
- 2 layers113 × 62.2 mm
FullScope
tvlad1234/pillScopePlus
Oscilloscope based around the STM32F401 Black Pill and a color LCD screen
15 parts165Apache-2.0 - 2 layers75.2 × 61.1 mm
- 2 layers144.1 × 182.2 mm
SHVC CPU-01
starlightk7/OpenSFC
OSHW Reproduction Parts related to the Super Famicom / Super Nintendo game console
498 parts114CERN-OHL-S-2.0
Questions
How big is the Phrog mainboard PCB?
It measures 92.4 × 51 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Phrog mainboard use?
41 parts, built around the LM358 and NAU7802KGI. 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 Phrog mainboard KiCad files?
From the Phalkon-Industries/phrog repository on GitHub, at the commit this page was made from: the board is phrog-mainboard/phrog-mainboard.kicad_pcb and its schematic phrog-mainboard/phrog-mainboard.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Phrog mainboard design in my own project?
Its repository publishes it under the CERN-OHL-S-2.0 licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).