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Since there is a flutter app that analyzes the CAN data and provides us with metrics on the vehicle, we need to be able to send WebSocket messages to the flutter app which can be set up through Node-Red. However, we also need to format these WebSocket messages as a JSON , similar to what is shown below on MongoDB Atlas.
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as shown below.
CAN Messages
Property | Sample Value |
|---|---|
Datetime | 2020-01-20 03:14:07 |
Name | MOTOR_CONTROLLER_VC |
Sender | MOTOR_CONTROLLER |
Data | { 'mc_voltage1':1234, ‘mc_current1’:1 ) |
GPS Data
Property | Value | Decoded |
|---|---|---|
Datetime | 030620 044747.0 | June 3, 2020 4:47:47.0 |
Latitude | 3722.117666 | 37° 22.117666' |
Latitude Direction | N | North |
Longitude | 12200.011971 | 122° 00.011971' |
Longitude Direction | W | West |
Altitude (meters) | 11.6 | 11.6 |
Speed (knots = 1.852 km/h) | 0.0 | 0.0 |
Course (degrees) | 0.0 | 0.0 |
The aggregate_can_data.py script allows us to grab data from the CAN bus, decode the message with our DBC file, write to a CSV, send to FRED with MQTT, and send to MongoDBto DynamoDB.
The GPS.py script allows us to grab GPS data from the vehicle.
Storing Data on the Raspberry Pi
In terms of storing data locally on the Raspberry Pi, the Python script aggregate_can_data.py can directly output the data to a CSV file locally on the Raspberry Pi. These files can be manually moved to Google Drive if necessary.
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