HTTP API Reference

This document provides a detailed reference for the HTTP API endpoints available in the Velovision Rearview system. The API is designed to facilitate communication with the server for retrieving system information, managing video files, and monitoring device status.

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Quick Reference Table

Functionality	HTTP Method	Path	Example curl Command
Basic test connection	GET	/	curl http://velovision-rearview.local:8000
Battery state of charge (%)	GET	/battery-percent	curl http://velovision-rearview.local:8000/battery-percent
Battery cell voltage (mV)	GET	/battery-millivolts	curl http://velovision-rearview.local:8000/battery-millivolts
CPU temperature (°C)	GET	/cpu-temp	curl http://velovision-rearview.local:8000/cpu-temp
External power status	GET	/is-charging	curl http://velovision-rearview.local:8000/is-charging
List local videos	GET	/list-local-videos	curl http://velovision-rearview.local:8000/list-local-videos
Delete all videos	GET	/wipe-local-videos	curl http://velovision-rearview.local:8000/wipe-local-videos
Download video	GET	/download-video	curl -o log0001.mp4 http://velovision-rearview.local:8000/download-video?/opt/velovision/standalone_videos/log0001.mkv
Download thumbnail	GET	/download-thumbnail	curl -o log0001.jpg http://velovision-rearview.local:8000/download-thumbnail?/opt/velovision/standalone_videos/log0001_1713198307.jpg

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Detailed Documentation

1. Basic Test Connection

Tests the connection to the server.

Path	/
HTTP Method	GET
Response	"Welcome to Velovision Rearview", 200

Example curl Command:

curl http://velovision-rearview.local:8000

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2. Battery State of Charge

Retrieves the battery’s state of charge as a percentage.

Path	/battery-percent
HTTP Method	GET
Response	Success: Percentage (integer), 200.
	Failure: "Failed to get battery state of charge", 500.

• The percentage is rounded to the nearest integer (e.g., 87).
• The value may exceed 100.

Example curl Command:

curl http://velovision-rearview.local:8000/battery-percent

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3. Battery Cell Voltage

Retrieves the battery cell voltage in millivolts.

Path	/battery-millivolts
HTTP Method	GET
Response	Success: Voltage (integer, mV), 200.
	Failure: "Failed to get battery voltage", 500.

• The voltage is rounded to the nearest millivolt (e.g., 3845).

Example curl Command:

curl http://velovision-rearview.local:8000/battery-millivolts

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4. CPU Temperature

Retrieves the CPU temperature in degrees Celsius.

Path	/cpu-temp
HTTP Method	GET
Response	Success: Temperature (integer), 200.
	Failure: "Failed to read CPU temperature", 500.

• The temperature is rounded to the nearest integer (e.g., 50).

Example curl Command:

curl http://velovision-rearview.local:8000/cpu-temp

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5. External Power Status

Checks if the device is connected to external power (e.g., USB-C).

Path	/is-charging
HTTP Method	GET
Response	Success: Boolean (true or false), 200.
	Failure: "Failed to get charging status", 500.

• true: USB-C power is connected and supplying power.
• false: USB-C power is not connected.

Example curl Command:

curl http://velovision-rearview.local:8000/is-charging

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6. List Local Videos

Retrieves a list of standalone video files stored on the server, including their paths and last update times.

Path	/list-local-videos
HTTP Method	GET
Response	JSON array of video metadata, 200.

Example Response:

[
  {
    "path": "/opt/standalone_videos/log0001.mkv",
    "date_updated": "1713198307"
  },
  ...
]

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Example curl Command:

curl http://velovision-rearview.local:8000/list-local-videos

7. Delete All Videos

Deletes all standalone video and thumbnail files stored on the server.

Path	/wipe-local-videos
HTTP Method	GET
Response	JSON object with status and message, 200.
	Failure: JSON object with error message, 500.

• Deletes all video and thumbnail files in the /opt/velovision/standalone_videos directory.
• Returns the number of files deleted upon success.

Example Response (Success):

{
  "status": "success",
  "message": "Deleted 10 video/image files."
}

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8. Download Video

Downloads a specified video file in .mp4 format.

Path	/download-video
HTTP Method	GET
Response	Video file (.mp4), 200.

• The query string (after ?) must include the full path to the .mkv video file on the server, as provided by the /list-local-videos endpoint.
• The video is converted to .mp4 format before being sent to the client.
• The .mp4 file is deleted from the server immediately after being sent.

Example curl Command:

curl -o log0001.mp4 http://velovision-rearview.local:8000/download-video?/opt/velovision/standalone_videos/log0001.mkv

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9. Download Thumbnail

Downloads the thumbnail image for a given video.

Path	/download-thumbnail
HTTP Method	GET
Response	Thumbnail image (.jpg), 200.

• The query string (after ?) must include the full path to the thumbnail file on the server.
• The thumbnail file name matches the video file name, with a timestamp appended.

Example curl Command:

curl -o log0001.jpg http://velovision-rearview.local:8000/download-thumbnail?/opt/velovision/standalone_videos/log0001_1713198307.jpg

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Error Handling

If the server receives a GET request with an invalid path, it responds with:

• Message: "Unknown GET request"
• Status Code: 501

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