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LIS2DW12TR overheating when connected with I2C

okay_computer
Associate

I have 4 LIS2DW12TR accelerometers connected to an Seeed Studio ESP-32 S3. The accelerometers get extremely hot when they're connected to 3.3V. They are not recognised with an I2C scan.

The accelerometers are connected to 2 pairs of SDA/SCL pins. Each accelerometer has the same layout, save the SAO pin which sets the I2C address.They each have an LED connected to show that the accelerometers are on.

They're connected as follows:

Screenshot 2024-06-07 at 9.32.39 PM.png

Screenshot 2024-06-07 at 9.32.39 PM.pngScreenshot 2024-06-07 at 9.37.16 PM.png

Screenshot 2024-06-07 at 9.37.22 PM.png

Screenshot 2024-06-07 at 9.37.30 PM.png

Screenshot 2024-06-07 at 9.37.07 PM.png

The LEDs don't turn on but the accelerometers get extremely hot.

Thing's I've tried so far:

  1. Did a continuity test with a multimeter (and very fine needles) - all the routes are connected as the schematics show, none are shorted.

  2. Removed R9 - the accelerometer became even hotter.

  3. Added a 27kΩ resistor to limit current to 100uA (data sheet asks for 90uA). I chose 27kΩ by measuring resistance between the 3.3V power route and the ground plane - it was 11kΩ. `27kΩ ≈ (3.3V/90uA) - 11kΩ`

I'm not sure what else can be causing the over heating, or what i'm missing here. This is my first time wiring an IC, so all advice is super helpful!

1 REPLY 1
Federica Bossi
ST Employee

Hi @okay_computer ,

Welcome to ST Community!

It seems that the pin 8 of LIS2DW12 is not connected to GND as datasheet reported.

Please try to send the wave signals of I2C1 and I2C2 to see if there are some BUS conflict.

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