Embedded | Backend/Data collection | Frontend/Dashboard
Collect data from Feedback Buttons from MQTT into DynamoDB aggregated tables
Micro-service that connects to an MQTT data stream of The Things Network and stores the aggregated and historical results on Amazon DynamoDB.
This component is designed to work with the Feedback Buttons by berkutta.
Make sure you have Node.js 8.x+ installed on your system.
Open your terminal, go to the project's folder and run:
npm install
Create a file named now-secrets.json at the top level of this project and enter the secrets (values starting with the @) from the now.json file. Example:
{
"@ttn-access-key": "ttn-account-v2.oioioioioioi",
"@aws-access-key-id": "iquwyeeuhdi234",
"@aws-secret-access-key": "ks239r83hd903rj34i4",
}
That's it! You're now ready to start the service.
Starting the service is as simple as running the following:
npm start
The service will start collecting and storing uplink messages.
The feedback buttons send a highly redundant data frame to cope with packet loss and network unreliability. Each data frame sends a counter of presses for each of the switches on the device, each taking one byte.
The following table describes application-specific fields:
| Field | Description |
|---|---|
| battery | Battery voltage |
| battery_percentage | Estimated remaining battery expressed as percentage |
| status | A value of 1 indicates this is the first transmission since power up, otherwise 0 |
| switch0 | Rolling over counter of switch #0 presses since power up, represented as 1 byte (0-255) |
| switch1 | Rolling over counter of switch #1 presses since power up, represented as 1 byte (0-255) |
| switch2 | Rolling over counter of switch #2 presses since power up, represented as 1 byte (0-255) |
| switch3 | Rolling over counter of switch #3 presses since power up, represented as 1 byte (0-255) |
Data from embedded devices is gathered by this service and stored permanently on Amazon DynamoDB.
There are two tables containing aggregated and historical data:
devices
Keeps aggregated information about devices in the system.
| Field | Description |
|---|---|
| device_name | Device name, set as primary partition key of the table. |
| first_battery_value | Battery voltage value recorded the first time the device has been seen by the system. Useful to calculate discharge rate. |
| first_seen | First time the device has been seen by the system. Expressed as ISO Date string (UTC+0) |
| hardware_serial | Hardware serial |
| last_seen | Last time the device has been seen by the system. Expressed as ISO Date string (UTC+0) |
| last_switch_0 | Last rolling over counter for switch #0 sent by the device. |
| last_switch_1 | Last rolling over counter for switch #0 sent by the device. |
| last_switch_2 | Last rolling over counter for switch #0 sent by the device. |
| last_switch_3 | Last rolling over counter for switch #0 sent by the device. |
| switch0 | Total count of switch #0 presses. |
| switch1 | Total count of switch #1 presses. |
| switch2 | Total count of switch #2 presses. |
| switch3 | Total count of switch #3 presses. |
messages
Keeps an append-only historical record of all messages sent from devices into the system.
| Field | Description |
|---|---|
| device_name | Device name, set as primary partition key of the table. |
| datetime | Date/time of the message, set as primary sort key of the table. Expressed as ISO Date string (UTC+0) |
| battery | Battery voltage |
| battery_percentage | Estimated remaining battery expressed as percentage |
| counter | LoRaWAN uplink frame counter |
| status | A value of 1 indicates this is the first transmission since power up, otherwise 0 |
| switch0 | Number of presses of switch #0 since last transmitted, represented as 1 byte (0-255) |
| switch1 | Number of presses of switch #1 since last transmitted, represented as 1 byte (0-255) |
| switch2 | Number of presses of switch #2 since last transmitted, represented as 1 byte (0-255) |
| switch3 | Number of presses of switch #3 since last transmitted, represented as 1 byte (0-255) |
| cumulative_switch_0 | Rolling over counter of switch #0 presses since last transmitted, represented as 1 byte (0-255) |
| cumulative_switch_1 | Rolling over counter of switch #1 presses since last transmitted, represented as 1 byte (0-255) |
| cumulative_switch_2 | Rolling over counter of switch #2 presses since last transmitted, represented as 1 byte (0-255) |
| cumulative_switch_3 | Rolling over counter of switch #3 presses since last transmitted, represented as 1 byte (0-255) |
The mapping between switch number and switch color is the following in the current setup:
| Switch # | Switch color |
|---|---|
0 |
red |
1 |
orange |
2 |
yellow |
3 |
green |
This project is licensed under the MIT License, see the LICENSE file for details.
- Fork it (https://github.com/gonzalocasas/taz-data-collector)
- Create your feature branch (
git checkout -b my-new-feature) - Commit your changes (
git commit -am 'Add some feature') - Push to the branch (
git push origin my-new-feature) - Create a new Pull Request :D
Based on the embedded implementation of feedback buttons by @berkutta of kilobyte.ch.