2 layers36 × 14 mm
TFASPDIMU01
ThunderFly-aerospace/TFASPDIMU01
SPI or I²C differential pressure sensor and IMU unit.
26 parts1GPL-3.0
2 layers30 × 15 mm
TFASPDIMU02
ThunderFly-aerospace/TFASPDIMU023I²C bus differential pressure sensor with IMU and Magnetometer.
- Size
- 30 × 15 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 43
- Nets
- 36
- Pads
- 143
- Tracks, vias
- 249, 70
- Pours
- 5
- Routed
- Yes
- KiCad
- KiCad 7 (file 20221018)
- Created
- 2 Aug 2021
- Updated
- 4 Feb 2026
Overview
TFASPDIMU02 is an open-source printed circuit board by ThunderFly-aerospace, from the ThunderFly-aerospace/TFASPDIMU02 repository on GitHub, published under the GPL-3.0 licence. It is a 2-layer board of 30 × 15 mm with 43 parts on 36 nets, routed with 249 tracks and 70 vias.
It is built around the PCA9617ADP, ICM-20948 and MIC5504-1.8YM5-TR, with the MIC5504-3.3YM5-TR, BZX585-B5V6,115-JSM and SM04B-GHS-TB among its other parts. Its parts include 13 capacitors, 12 resistors, 6 ICs, 2 diodes and 1 connector. It belongs with the sensors and measurement boards of this library.
Main components
6
PCA9617ADP
TSSOP-8Level shifting、Bus capacitance isolation、Power-off isolation TSSOP-8 Signal Buffers, Repeaters, Splitters ROHSNXP SemiconductorsSignal Buffers, Repeaters, Splitters
ICM-20948
QFN-24(3x3)-40℃~+85℃ 0.5KB 1.71V~3.6V 16bit 8uA Accelerometer Gyroscope SPI、I2C X,Y,Z X,Y,Z ±16g ±2000dps QFN-24(3x3) Accelerometers ROHSTDK InvenSenseAccelerometers
MIC5504-1.8YM5-TR
SOT-23-5-40℃~+125℃@(Tj) 1 1.8V 175uVrms 300mA 380mV@(300mA) 5.5V 55uA 60dB@(1kHz) Fixed Over Current Protection、Over Temperature Protection Positive SOT-23-5 Voltage Regulators - Linear, Low Drop Out (LDO) Regulators ROHSMicrochip TechnologyVoltage Regulators - Linear, Low Drop Out (LDO) RegulatorsMIC5504-3.3YM5-TR
SOT-23-5-40℃~+125℃@(Tj) 1 160mV@(300mA) 175uVrms 3.3V 300mA 38uA 5.5V 60dB@(1kHz) Fixed Over Current Protection Positive SOT-23-5 Voltage Regulators - Linear, Low Drop Out (LDO) Regulators ROHSMicrochip TechnologyVoltage Regulators - Linear, Low Drop Out (LDO) Regulators
BZX585-B5V6,115-JSM
SOD-523SOD-523 Zener Diodes ROHSJSMSEMIZener Diodes
SM04B-GHS-TB
SMD,P=1.25mm,卧贴-25℃~+85℃ 1 1.25mm 1A 1x4P 4 4.13mm 4.25mm 4P 50V 8.25mm Auxiliary Solder Pin GH PA9T Phosphor bronze Surface Mount, Right Angle Tin UL94V-0 White SMD,P=1.25mm,卧贴 Wire To Board Connector ROHSJSTWire To Board Connector
README
README.mdTFASPDIMU02 - Differential pressure sensor and IMU
ThunderFly TFASPDIMU02 is I2C bus sensor board equipped with a differential pressure sensor (Sensirion SDP3x) and 9-axis motion tracking sensor (ICM-20948). The board is equipped with a 4-pin JST-GH connector. The sensor board is designed for multiple uses. It can be used as a self-adjusting anemometer WINDGAUGE03 or as an airspeed sensor for UAVs with optional function as the external magnetometer. The featured use (after firmware improvement) could be an angle of attract sensor, stall detector, or vibration (Flutter) detector.
TFASPDIMU is commercially available from ThunderFly s.r.o., write an email to info@thunderfly.cz or shop at Tindie store.
Specification
- Type: Differential and 9-axis motion sensor board
- Mass: 3 g
- Size: 30 x 15 mm
- Power input: +5 V
- Connection: 4pin JST-GH connector PixHawk compatible
SDP3x differential pressure sensor
- Range: +/- 125/500/1500 Pa (depending on exact sensor type SDP33 by default)
- Excellent accuracy and repeatability, even below one Pascal
- No zero-point offset, no temperature drift
- Calibrated and temperature-compensated
- Fast sampling time of 2kHz at 16 bit resolution
- I2C address: 0x21 (0d33), could be changed by JP2 and/or resorderig the R10 value.
ICM-20948 9-axis IMU unit
- 3-axis gyroscope, 3-axis accelerometer, 3-axis compass (magnetometer)
- Onboard Digital Motion Processor (DMP)
- On-chip 16-bit ADCs and Programmable Filters
- 7 MHz SPI or 400 kHz Fast Mode I²C
- Digital temperature sensor
- Default I2C address: 0x68 (0d104), can be changed to 0x69 (0d105) by adjusting the JP1.
Example of uses
WINDGUAGE - weather vane sensor
Ground control station anemometer WINDGAUGE03 is based on a TFASPDIMU sensor which is used for both wind direction and wind speed measurement.
TFSLOT01 - UAV airspeed sensor
Our TFSLOT sensor is an airspeed sensor for use mainly on UAVs. Due to the 3D printed case, optimizing housing according to the sensor's location on the UAV and tuning its characteristics is possible. The first use of this sensor was on our autogyro TF-G2.
More details about this solution are available in the repository TFSLOT01.
TFPIPE01 - UAV airspeed sensor
The symmetric variant of TFSLOT sensor for different mounting options TFPIPE01.
TFVENTUFO - innovative anemometer
This anemometer is also based on the venturi effect. Thanks to a clever design, it will measure the wind speed from all directions (without knowing the direction).
Angle of Attack sensor
In case of mounting on slip-ring bearing the sensor could sense air AoA of the vehicle.
Stall detector
The venturi geometry could also be inverted therefore the pressure ports look in open airflow. That results in the ability to detect stalls on wings by detecting the absence of pressure difference and increasing pressure fluctuations on the wing surface.
Hardware
Electronics schema
Full schema is available in PDF
PCB dimensions
Pressure sensor connections are aligned to the center of the PCB width.
I2C connector pinout
| Signal | Pixhawk Color | ThunderFly color |
|---|---|---|
| +5V | Red |  Red |
| SCL | Black |  Yellow |
| SDA | Black |  Green |
| GND | Black |  Black |
Pixhawk pinout is listed according to the Pixhawk connector standard.
PixHawk autopilot connection cable
To increase the transmission quality, it is mandatory to create twisted pairs of SDA, GND, and SCL,+5V on the cable (as shown in the image)
- 10 twists for each pair SCL/+5V and SDA/GND per 30cm cable length
- 4 turns/twists of pairs per 30cm cable length.
Usage
Python
For reading data from the sensor, we have prepared a Python script in the PyMLAB library that uses the pySMBus to read data. It can be used directly from a computer with a corresponding converter (for example MLAB USBI2C01A) or with one-board computers (Odroid, raspberry, and similar) that have own smbus output.
Calibration verification
Calibration can be verified by mounting an anemometer to the car roof and comparing it to GNSS speed. This needs to be done in windless weather.
PX4
There exists a pull-request of modified SDP33 driver into PX4 stack.
The main use of this sensor is as an airspeed sensor. It can also be used as an external magnetometer and thermometer.
Ardupilot
We are currently unable to implement the sensor in the Ardupilot flight stack. However, we will be happy to assist with implementation. You can contact us
Parts
43| Qty | Value | Footprint | References |
|---|---|---|---|
| 8 | 100nF | Capacitor_SMD:C_0402_1005Metric | C1, C2, C3, C4, C9, C10, C12, C13 |
| 6 | 10k | Resistor_SMD:R_0402_1005Metric | R4, R5, R6, R7, R8, R9 |
| 4 | 1uF | Capacitor_SMD:C_0402_1005Metric | C5, C6, C7, C8 |
| 4 | HOLE_TF | Mlab_Mechanical:dira_3mm | M1, M2, M3, M7 |
| 3 | 2k7 | Resistor_SMD:R_0402_1005Metric | R2, R3, R10 |
| 2 | 75R | Resistor_SMD:R_0402_1005Metric | R1, R11 |
| 2 | Fiducial | Fiducial:Fiducial_1mm_Mask2mm | FID1, FID2 |
| 2 | PCA9617A | Package_SO:TSSOP-8_3x3mm_P0.65mm | U3, U6 |
| 2 | SolderJumper_3_Bridged12 | Jumper:SolderJumper-3_P1.3mm_Bridged12_RoundedPad1.0x1.5mm | JP1, JP2 |
| 1 | 10uF | Capacitor_SMD:C_0402_1005Metric | C11 |
| 1 | 180R | Resistor_SMD:R_0402_1005Metric | R12 |
| 1 | BZX585-B5V6.115 | Diode_SMD:D_SOD-523 | D2 |
| 1 | GREEN | LED_SMD:LED_0603_1608Metric_Pad1.05x0.95mm_HandSolder | D1 |
| 1 | ICM-20948 | Sensor_Motion:InvenSense_QFN-24_3x3mm_P0.4mm | U2 |
| 1 | LOGO | MLAB_LOGA:TF 14x6,6 | G*** |
| 1 | MIC5504-1.8YM5-TR | Package_TO_SOT_SMD:SOT-23-5 | U5 |
| 1 | MIC5504-3.3YM5-TR | Package_TO_SOT_SMD:SOT-23-5 | U4 |
| 1 | SDP3x | Mlab_IO:SDP3x | U1 |
| 1 | SM04B-GHS-TB | Connector_JST:JST_GH_SM04B-GHS-TB_1x04-1MP_P1.25mm_Horizontal | J1 |
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Questions
How big is the TFASPDIMU02 PCB?
It measures 30 × 15 mm and has 2 copper layers, 1.6 mm thick.
What parts does the TFASPDIMU02 use?
43 parts, built around the PCA9617ADP, ICM-20948, MIC5504-1.8YM5-TR and MIC5504-3.3YM5-TR. 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 TFASPDIMU02 KiCad files?
From the ThunderFly-aerospace/TFASPDIMU02 repository on GitHub, at the commit this page was made from: the board is hw/sch_pcb/TFASPDIMU02.kicad_pcb and its schematic hw/sch_pcb/TFASPDIMU02.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the TFASPDIMU02 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).