2 layers61 × 48 mm
4 layers74 × 28 mm
OpenFlowMeter
JochiSt/OpenFlowMeter6Measuring Flow
- Size
- 74 × 28 mm
- Copper layers
- 4
- Thickness
- 1.56 mm
- Parts
- 156
- Nets
- 109
- Pads
- 458
- Tracks, vias
- 675, 186
- Pours
- 4
- Routed
- Yes
- KiCad
- KiCad 9.0 (file 20241229)
- Created
- 29 Mar 2021
- Updated
- 18 Feb 2026
Overview
OpenFlowMeter is an open-source printed circuit board by JochiSt, from the JochiSt/OpenFlowMeter repository on GitHub, published under the GPL-3.0 licence. It is a 4-layer board of 74 × 28 mm with 156 parts on 109 nets, routed with 675 tracks and 186 vias.
It is built around the R-78C3.3-1.0, SN65HVD231D and BME680, with the LT1491CS#PBF, TMP100NA and LT1492CN8 among its other parts. Its parts include 71 resistors, 40 capacitors, 13 ICs, 7 connectors and 4 diodes. It belongs with the interfaces and adapters boards and the STM32 boards of this library.
Main components
8
R-78C3.3-1.0
SIP-3-40℃~+85℃ 1 10.4mm 11.6mm 1A 1mA 3.3V 30mVp-p、75mVp-p 350kHz 470uF、6800uF 7V~42V 8.5mm 89% Buck-Boost Short Circuit Protection、Over-temperature protection、Automatic fault recovery ±3% SIP-3 DC-DC Power Modules ROHSRECOM PowerDC-DC Power Modules
SN65HVD231D
SOIC-8-40℃~+85℃ 17mA 1Mbps 1uA 3V~3.6V CAN Transceiver SOIC-8 CAN Transceivers ROHSTexas InstrumentsCAN Transceivers
BME680
LGA-8-40℃~+85℃ 0.12hpa 0.6hpa 1.3pa/K 1.71V~3.6V 150nA 30Kpa~1.1bar I2C、SPI Temperature Sensor LGA-8 Pressure Sensors ROHSBosch SensortecPressure Sensors
LT1491CS#PBF
SO-140℃~+70℃ SO-14 Operational Amplifier ROHSAnalog DevicesOperational Amplifier
TMP100NA
SOT23-6-55°C to +125°C, ±3.0°C Accuracy, Digital Temperature Sensor with I2C InterfaceTexas InstrumentsUncategorised
LT1492CN8
PDIP-8PDIP-8 Precision Op Amps ROHSAnalog DevicesPrecision Op Amps
24LC64(LX)
SOP-8-40℃~+85℃ 1,000,000 cycles 1.8V~5.5V 100 Years 1MHz 5ms 64Kbit Hardware write protection function、Noise suppression function I2C SOP-8 EEPROM ROHSlingxingicEEPROM
BC556
TO-92-55℃~+150℃ 1 PNP 100mA 100nA 150MHz 300mV 5V 625mW 65V 800 PNP TO-92 Bipolar (BJT) ROHSJiangsu Changjing Electronics Technology (CJ)Bipolar (BJT)
README
README.mdOpenFlowMeter
Purpose
Measuring flow of gases and maybe liquids.
Principle
Measures the volume flow by the amount of heat transferred to a gas flow. This can be either done by constantly heating the sensor or by evaluating temperature cycles.
Hardware
The hardware is based around two voltage controlled current sources, which are controlled and readout via a STM32F103 microcontroller. The controller provides the ADCs for reading the voltages and current as well as the digital communication to the outside of the PCB.
Photographs of the populated PCB
References
The working principle of this device is adapted from a proposal of the LHC gas group at CERN. In addition there is a report of a student, explaining / proposing this technique more in detail.
[2] F.Hahn, S.Haider, M. v.d. Klis, C. Zinoni, Proposal for a gas flow meter at LHC, 10.2.2001
PCBs
PCBs are available from AISLER https://aisler.net/p/MVHMBVKT
Parts
156| Qty | Value | Footprint | References |
|---|---|---|---|
| 27 | 100n | Capacitor_SMD:C_0603_1608Metric | C12, C14, C15, C16, C17, C18, C21, C22, C23, C24, C25, C26, C27, C28, C29, C30 +11 |
| 23 | 10k | Resistor_SMD:R_0603_1608Metric | R11, R12, R22, R25, R26, R29, R30, R32, R34, R41, R54, R55, R56, R57, R62, R63 +7 |
| 6 | 0 | Resistor_SMD:R_0603_1608Metric | R13, R27, R28, R31, R66, R67 |
| 6 | 47k | Resistor_SMD:R_0603_1608Metric | R2, R4, R16, R18, R47, R49 |
| 5 | 100n 50V | Capacitor_SMD:C_0603_1608Metric | C1, C2, C3, C4, C11 |
| 5 | 120 | Resistor_SMD:R_0603_1608Metric | R14, R58, R59, R60, R61 |
| 5 | LT1492 | Package_SO:SOIC-8_3.9x4.9mm_P1.27mm | U1, U3, U6, U11, U13 |
| 4 | 10n | Capacitor_SMD:C_0603_1608Metric | C7, C8, C36, C37 |
| 4 | 22k | Resistor_SMD:R_0603_1608Metric | R9, R10, R23, R24 |
| 4 | 2k2 | Resistor_SMD:R_0603_1608Metric | R35, R36, R37, R38 |
| 4 | 4k7 | Resistor_SMD:R_0603_1608Metric | R42, R43, R44, R45 |
| 4 | 5k6 | Resistor_SMD:R_0603_1608Metric | R50, R51, R52, R53 |
| 3 | MountingHole_Pad | MountingHole:MountingHole_3.2mm_M3_Pad_Via | H2, H3, H4 |
| 2 | 100 | Resistor_SMD:R_0603_1608Metric | R5, R19 |
| 2 | 100k | Resistor_SMD:R_0603_1608Metric | R3, R17 |
| 2 | 1k | Resistor_SMD:R_0603_1608Metric | R1, R15 |
| 2 | 220 | Resistor_SMD:R_0603_1608Metric | R7, R21 |
| 2 | 27p | Capacitor_SMD:C_0603_1608Metric | C19, C20 |
| 2 | 33k | Resistor_SMD:R_0603_1608Metric | R46, R48 |
| 2 | 47 | Resistor_SMD:R_0603_1608Metric | R6, R20 |
| 2 | 56k | Resistor_SMD:R_0603_1608Metric | R39, R40 |
| 2 | BC556 | Package_TO_SOT_THT:TO-92_Inline | Q1, Q2 |
| 2 | LED yl | LED_SMD:LED_0603_1608Metric | D2, D3 |
| 2 | Screw_Terminal_01x04 | Connector_Wago:Wago_733-364_1x04_P2.50mm_Horizontal | J1, J2 |
| 1 | 12 MHz | Crystal:Crystal_SMD_EuroQuartz_MT-4Pin_3.2x2.5mm | Y1 |
| 1 | 1u | Capacitor_SMD:C_0603_1608Metric | C13 |
| 1 | 1u 50V | Capacitor_SMD:C_0603_1608Metric | C10 |
| 1 | 24LC64 | Package_DIP:DIP-8_W7.62mm | U7 |
| 1 | 4066 | Package_SO:SOIC-14_3.9x8.7mm_P1.27mm | U12 |
| 1 | BME680 | digikey-footprints:BME680 | U10 |
| 1 | Conn_01x03 | Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical | J5 |
| 1 | Conn_01x04 | Connector_PinHeader_2.54mm:PinHeader_1x04_P2.54mm_Vertical | J3 |
| 1 | Conn_02x03_Odd_Even | w_conn_strip:vasch_strip_3x2_90 | J4 |
| 1 | Conn_02x03_Odd_Even | Connector_PinHeader_2.54mm:PinHeader_2x03_P2.54mm_Vertical_SMD | J7 |
| 1 | Conn_02x04_Odd_Even | Connector_PinHeader_2.54mm:PinHeader_2x04_P2.54mm_Vertical_SMD | J6 |
| 1 | G*** | kibuzzard-6401F211 | kibuzzard-6401F211 |
| 1 | G*** | kibuzzard-6401F2BC | kibuzzard-6401F2BC |
| 1 | G*** | kibuzzard-6401F1F3 | kibuzzard-6401F1F3 |
| 1 | G*** | kibuzzard-61DDB4F7 | kibuzzard-61DDB4F7 |
| 1 | G*** | kibuzzard-6401F2D0 | kibuzzard-6401F2D0 |
| 1 | G*** | kibuzzard-6401F252 | kibuzzard-6401F252 |
| 1 | G*** | kibuzzard-6401F2C5 | kibuzzard-6401F2C5 |
| 1 | G*** | kibuzzard-61DDB4E3 | kibuzzard-61DDB4E3 |
| 1 | G*** | kibuzzard-6401F165 | kibuzzard-6401F165 |
| 1 | Jumper_2_Bridged | Jumper:SolderJumper-2_P1.3mm_Bridged_RoundedPad1.0x1.5mm | JP2 |
| 1 | Jumper_2_Open | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | JP1 |
| 1 | LED gn | LED_SMD:LED_0603_1608Metric | D4 |
| 1 | LED rd | LED_SMD:LED_0603_1608Metric | D1 |
| 1 | LOGO | MadeByJochen:MadeByJochen_5x5 | G*** |
| 1 | LT1491CS | Package_SO:SOIC-14_3.9x8.7mm_P1.27mm | U8 |
| 1 | R-78C3.3-1.0 | Converter_DCDC:Converter_DCDC_RECOM_R-78E-0.5_THT | U4 |
| 1 | SN65HVD231 | Package_SO:SOIC-8_3.9x4.9mm_P1.27mm | U5 |
| 1 | STM32F103C8Tx | Package_QFP:LQFP-48_7x7mm_P0.5mm | U2 |
| 1 | SolderJumper_3_Bridged12 | Jumper:SolderJumper-3_P1.3mm_Bridged12_RoundedPad1.0x1.5mm | JP3 |
| 1 | TMP100 | Package_TO_SOT_SMD:SOT-23-6 | U9 |
| 1 | dnp | Resistor_SMD:R_0603_1608Metric | R33 |
The 154 most common of 156 parts.
Questions
How big is the OpenFlowMeter PCB?
It measures 74 × 28 mm and has 4 copper layers, 1.56 mm thick.
What parts does the OpenFlowMeter use?
156 parts, built around the R-78C3.3-1.0, SN65HVD231D, BME680 and LT1491CS#PBF. 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 OpenFlowMeter KiCad files?
From the JochiSt/OpenFlowMeter repository on GitHub, at the commit this page was made from: the board is OpenFlowMeter.kicad_pcb and its schematic OpenFlowMeter.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the OpenFlowMeter 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).
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