ADXL345 Accelerometer with Pro Micro I2C not working

Projects General Guidance
1

Heya there,
I've been trying to use a ADXL345 on my Pro Micro, and I can't get any result from it : the test code results in nothing at all being printed in the serial monitor, and the I2C scanner code either print nothing, or print every possible address in a loop, when I disable the error = Wire.endTransmission(); line of code.

I've had a very similar issue with a magnetometer very recently, and I believe the two might be linked.
I've redone all soldering, because the old one were a bit shabby, but nothing changed. I also checked with a multimeter that the connections were unbroken, and it seems fine.

2

Your topic has been moved to a more suitable location on the forum as this has nothing to do with Avrdude, stk500 or Bootloader.

3

You need to provide facts like schematics and code.
Read the advise in "How to get the best from forum".

4

Oh, right !
The code and wiring I did was what's written on this website

5

You're using a Pro Micro, not a Nano. So to which pins did you connect SDA and SCL?

If you don't want to miss data, your code also needs to contain while(!Serial) after Serial.begin() in setup().

6

I connected SDA to 2, and SCL to 3.
Do you think missing data could cause this ?

7

That seems OK. Power connections?

No, I was just wondering if you used the correct pins.

8

VCC is connected to the sensor board's VCC ( and the pullup resistors that I just added, as in this picture ), GND is connected to the sensor board's GND.

Port 2 is connected to SDA and the pullup resistor, to VCC
Port 3 is connected to SCL and the pullup resistor, to VCC

Btw, now the error message is different, it simply print "No I2C devices found" looping.

9

That's not the best way to provide facts. Read this link: How to get the best out of this forum - Using Arduino / Project Guidance - Arduino Forum

10

The ADXL345 is a 3.3V device. Unless logic level shifters for SDA and SCL are included in the sensor module, you need to add them to the 5V Arduino.

Test the wiring and communications using the I2C address scanner program.

11

Not the way helpers like it. You dig out the code and schematics and post them here. The more work and time expected from helpers the less number of people will take on Your question and the more You have to wait. Plowing through videos and project plans is the work You can, and should do, not we.

12

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