zackoch/dual-adxl345

Setup

# install git and python3-dev
sudo apt-get install python3-dev git
# clone repo
git clone https://github.com/zackoch/dual-adxl345.git
# create virtual environment
python3 -m venv venv
# activate venv
source ./venv/bin/activate
# install requirements
pip install -r requirements.txt
# run
python main.py

Connections to Raspberry Pi 5

ADXL345_0

Pin	Raspberry Pi Pin
GND	GND
VCC	3.3V
CS	GPIO8
SD0	GPIO9
SDA	GPIO10
SCL	GPIO11

ADXL345_1

Pin	Raspberry Pi Pin
GND	GND
VCC	3.3V
CS	GPIO18
SD0	GPIO19
SDA	GPIO20
SCL	GPIO21

Button

Pin	Raspberry Pi Pin
Pole A	GND
Pole B	GPIO26

Setting the Data Rate

The available data rates for the ADXL345's are defined in a dictionary as follows:

avail_data_rates = {
    "3200hz": 0xF,
    "1600hz": 0xE,
    "800hz": 0xD,
    "400hz": 0xC,
    "200hz": 0xB,
    "100hz": 0xA,
    "50hz": 0x9,
    "25hz": 0x8,
    "12.5hz": 0x7,
    "6.25hz": 0x6,
    "3.13hz": 0x5,
    "1.56hz": 0x4,
    "0.78hz": 0x3,
    "0.39hz": 0x2,
    "0.20hz": 0x1,
    "0.10hz": 0x0,
}

To set the data rate, you need to modify the data_rate variable. The data_rate variable should be set to one of the values from the avail_data_rates dictionary. For example, to set the data rate to 3200 Hz, you would set the data_rate variable as follows:

data_rate = avail_data_rates['3200hz']

To change the data rate, simply replace '3200hz' with the desired rate from the dictionary. For instance, if you want to set the data rate to 100 Hz, you would use:

data_rate = avail_data_rates['100hz']

Make sure to choose the appropriate data rate for your specific application needs.

Output Data

Data is stored in three folders:

./data

• contains the database - each run creates a new timestamped database
• db columns include:
  • timestamp (unix)
  • sensor "id" (0,1)
  • x-value
  • y-value
  • z-value
• database is not overwritten
• database contains entire run data

./plot

• graph with last 180 seconds of data from button press or ctrl+c

./plot_overlay

• graph with both sensors on the same graph of last 180 seconds of data from button press or ctrl+c