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QT Py S3 8MB (No PSRAM)
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LiPo Backpack
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2x3 2.54mm SMD Female Connector
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NAU7802 ADC
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LiPo Battery
- Specifications: 3.7V 350mAh with JST-PHR-2 Connector (LP552035)
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Load Cell
- Specifications: 25mm 0-200kg (Model: cn1501541594)
- Manufacturer: XNQ Electric Company Store
- Purchase Link
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3x M3 10mm Screws
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STEMMA QT/Qwiic JST SH 4-Pin Cable (≥50mm)
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USB-C Connector (7x12x26mm)
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Rope (6mm diameter, ca 1m length)
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Slide Switch with Cables
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4x Screws (3x12mm)
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3D Printed Parts in PETG:
- Use 0.26 mm layer height, 4 perimeters, 50 percent infill
- Set bridge angle to 90 degrees
- Enable support for the edge
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Remove the existing switch from the LiPo backpack using hot air (350°C)
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Solder the 3x2 female connector onto the board using hot air or reflow soldering
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Solder the LiPo backpack to the QT Py S3
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Prepare two 4cm cables with crimped ends and connect them between the 3x2 connector and the slide switch
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Cut the load cell sensor cable to 7cm length
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Carefully remove the outer insulation and shielding
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Strip approximately 2cm of insulation from each of the inner cables
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Neatly twist and roll up the exposed cable ends to prevent fraying
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Connect the prepared cables to the corresponding terminals on the NAU7802 ADC board
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Insert the 3x M3 10mm screws into the load cell sensor mounting holes to secure the rope
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Connect the NAU7802 to the QT Py using the STEMMA QT/Qwiic cable
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Apply adhesive to mount the USB-C connector and slide switch in their designated positions
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Ensure all components are securely mounted and connections are tight
- Battery Testing Results
- Voltage: 2.9V under load, 3.6V from USB
- Operating Time: 3.5 hours
- Deep Sleep Mode: Battery did only last ~10 hours, so not used
- Adafruit QT Py ESP32-S3 Compatibility:
- 4MB Flash 2MB PSRAM version not supported ("
no module named _bleio") - Only 8MB No PSRAM version is supported
- Compatibility Matrix
- 4MB Flash 2MB PSRAM version not supported ("