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wollewald / ADXL345_WE

Arduino Library for the ADXL345 accelerometer. I2C and SPI are implemented.
https://wolles-elektronikkiste.de/en/adxl345-the-universal-accelerometer-part-1
MIT License
40 stars 9 forks source link
accelerometer adxl345 arduino arduino-library easy-to-use i2c spi

readme

ADXL345_WE

Arduino Library for the ADXL345 accelerometer.

I have tried to create a library for the ADXL345 which is easy to use for people who don't want to deal with all the registers. Therefore I have added lots example sketches which will enable you to deal even with the more complex features such as the FIFO modes. Howerever I still recommend to have a look into the data sheet to get a deeper understanding.

You can use both I2C and SPI. If you want to find out how to use SPI, look at the ADXL345_SPI_basic_data.ino.

A detailed tutorial is available:

https://wolles-elektronikkiste.de/adxl345-teil-1 (German)

https://wolles-elektronikkiste.de/en/adxl345-the-universal-accelerometer-part-1 (English)

If you are not so much experienced with the ADXL345, I recommend to work through the examples in the following order:

1) ADXL345_basic_data 2) ADXL345_SPI_basic_data 3) ADXL345_calibration 4) ADXL345_angles_orientation 5) ADXL345_pitch_roll_corrected_angles 6) ADXL345_sleep 7) ADXL345_free_fall_interrupt 8) ADXL345_data_ready_interrupt 9) ADXL345_activity_inactivity_interrupt 10) ADXL345_auto_sleep.ino 11) ADXL345_single_tap 12) ADXL345_double_tap 13) ADXL345_fifo_fifo 14) ADXL345_fifo_stream 15) ADXL345_fifo_trigger

To develop this library I have worked with a ADXL345 module. It should also work with the bare ADXL345 IC. For the module I have noticed that the power consumption is much higher than mentioned in the data sheet. I think the issue is the voltage converter on the module. You can reduce the power consumption by choosing 3.3 volts instead of 5 volts. At least this worked with my module.

If you like my library please give it a star. If you don't like it I would be happy to get feedback. And if you find bugs I will try to eliminate them as quickly as possible.

If SPI does not work

My library has implemented SPI 4-Wire. Some modules have SDO connected GND via an 0 ohm resistor. With this resistor only SPI 3-Wire would work. Your options are:

1) Remove the 0 ohm resistor connected to SDO (R4 on my module) 2) Replace the 0 ohm resistor connected to SDO by an internal or external pull-down resistor of 4.7 kohm or 10 kohm 3) Find another library which supports SPI 3-Wire

ADXL345_hack

Another SPI issue might occur when using ESP8266 boards like the WEMOS D1 mini or NodeMCU. The standard CS Pin (e.g. D8/GPIO15 on a WEMOS D1 mini or NodeMCU) might not work since the CS Pin on most ADXL345 modules has a pull-up resistor. And if D8 is high at reset, the ESP8266 will not boot. In that case choose a different ESP8266 pin as CS!