/bike-collector

Primary LanguagePython

Basic record data on raspberry

Hardware

  • Raspberry Pi 4B
  • PiCam
  • MPU6050 connected to the I2C
  • uBloxGPS connected by USB
  • a switch or equivalent connected between GND and GPIO26

Install

1. Download the code

By git

git clone https://github.com/guissalustiano/bike-collector.git

By zip file

cd ~/Documents/ # or any folder that you want to download the project
wget https://github.com/guissalustiano/bike-collector/archive/refs/heads/main.zip
unzip main.zip
mv bike-collector-main/ bike-collector/
cd bike-collector

2. Create a python virtual env

Inside the folder that you downloaded, run:

python3 -m venv --system-site-packages .venv

Every time that you access a new shell to run the project you need to activate the environment with:

source .venv/bin/activate

To deactivate the python environment run

deactivate

You can find more information here.

3. Install dependencies

First, install Picamera and SMBus on the system.

sudo apt install -y python3-picamera
sudo apt install -y python3-smbus

Then install the extra python packages.

pip install -r requirements.txt

Run

Change the variable PATH with the python code directory (pwd), then run the script as a normal python code.

python collect.py

It will wait until the switch is held for 5 seconds (to avoid bounce) to start the record, and when the switch is released the record is stopped immediately to start the record, and when the switch is released the record is stopped immediately.

Automatic start of the script on startup

Usually, you don't have access to the rpi console when you make the measures, so it's useful to config the program to run on startup and restart automatically in case of error.

To do it, you need to config a systemmd service and enable it.

First change the directory on the collector.service.

sudo cp collector.service /etc/systemd/system/bike-collector.service
sudo systemctl daemon-reload
sudo systemctl enable bike-collector.service

# Check if it is running
systemctl status bike-collector.service

Reading the data

Move data to your computer

You can use the rpi UI or do it by the command line with scp.

Reading the video frames

You can use ffmeg to extract the frames from the video (ex: ffmpeg -i file:video.mjpeg video/frame%d.png). Then you need to check the timestamp on the first frame and from that you can use the *.timestamp.txt files to calculate the timestamp of the next frames.

Reading the IMU data

The imu data is a simple csv with the following colluns:

  • timestamp - YYYY-MM-DD HH:MM:SS:mmmmmm (iso format)
  • temperature
  • accelerometer X
  • accelerometer Y
  • accelerometer Z
  • gyroscope X
  • gyroscope Y
  • gyroscope Z

References