OpenBeken HTTP API: Read Channel 0 Value on BK7231T, Tasmota-Style Commands

User question

how to read via http api the channel 0 value ?

Artificial Intelligence Response

Direct answer to the question

• Send an HTTP GET to one of these endpoints:
  • http://DEVICE_IP/cm?cmnd=Ch0
  • http://DEVICE_IP/cm?cmnd=GetChannel%200
• Both return the current value of channel 0. Use URL-encoding for spaces. Example:
  • curl -s "http://192.168.1.50/cm?cmnd=GetChannel%200" → plain value. (elektroda.com)
• To fetch many values at once: http://DEVICE_IP/cm?cmnd=json or …cm?cmnd=getState (JSON). (elektroda.com)

Key points

• Channel indices are zero‑based in OpenBeken (channel 0 is valid). You will see $CH0 used throughout the firmware and scripting, confirming index 0 exists. (newreleases.io)

Detailed problem analysis

• Command interface: OpenBeken implements a Tasmota‑style command endpoint “/cm?cmnd=”. Whatever you would type in the device console goes into cmnd=. For single values, ChN or GetChannel N respond with the raw scalar; for structured snapshots, json/getState respond with JSON. (elektroda.com)
• Zero‑based channels: The project and examples consistently reference channel 0 ($CH0, OnChannelChange 0), which implies that channel numbering includes 0. Therefore “Ch0” and “GetChannel 0” are the correct ways to address the first channel over HTTP. (newreleases.io)
• Data types: A channel may hold relay state (0/1), dimmer/PWM (0–100 or 0–255 depending on type), ADC/sensor readings, counters, etc. The HTTP command returns that underlying value. (elektroda.com)
• Expected replies:
  • Ch0 / GetChannel 0 → text like 0, 1, 53.7
  • json / getState → JSON object with a Channels map that will include the current value of index 0 when that channel is in use. (elektroda.com)

Current information and trends

• GetChannel was added alongside other REST improvements in recent 1.17.x+ builds; the classic ChN form remains supported and is fastest for polling a single value. (elektroda.com)
• Scripting and automations widely use $CH0/$CHn, confirming zero‑based access across current firmware lines (1.12.x onward). (newreleases.io)

Supporting explanations and details

• Minimal examples:
  • Browser: http://192.168.1.50/cm?cmnd=Ch0
  • curl: curl -s "http://192.168.1.50/cm?cmnd=GetChannel%200"
  • All channels (JSON): curl -s "http://192.168.1.50/cm?cmnd=json" (elektroda.com)
• Why you may see “Ch1” in some posts: examples often show arbitrary indices; however, project change logs and scripting examples use CH0 explicitly. If you truly need the first channel, use index 0. (newreleases.io)

Ethical and legal aspects

• Secure access if the device is reachable outside your LAN. Enable HTTP auth on OpenBeken (setWebAuth …) or place it behind a trusted HTTPS reverse proxy. Avoid exposing unauthenticated control endpoints to the internet. (elektroda.com)

Practical guidelines

• Authentication: If web auth is enabled, include Basic Auth, e.g. curl -u admin:password "http://IP/cm?cmnd=Ch0". (elektroda.com)
• Polling: For dashboards, a 2–5 s interval is usually fine; for near‑real‑time logic prefer MQTT or event handlers rather than rapid HTTP polling. (elektroda.com)
• Troubleshooting:
  • If reply is empty or “channel not initialized”, make sure channel 0 exists/has a role or set an initial value once (SetChannel 0 0). (elektroda.com)
  • Verify device IP/connectivity first (ping IP). If you changed the HTTP port, include “:PORT”.

Possible disclaimers or additional notes

• Documentation and forum posts sometimes say “indices start at 1.” Current firmware and scripting clearly support index 0 ($CH0, OnChannelChange 0). If your specific build behaves differently, use json/getState to inspect what indices are reported on your device. (newreleases.io)

Suggestions for further research

• If you’ll integrate more deeply, consider using MQTT for push updates of channels, or the device’s JSON snapshots to reduce round‑trips. The Elektroda tutorials and the OpenBeken repo/wiki provide many end‑to‑end examples. (elektroda.com)

Brief summary

• Use http://DEVICE_IP/cm?cmnd=Ch0 or http://DEVICE_IP/cm?cmnd=GetChannel%200 to read channel 0 via HTTP. For many values at once, use …cm?cmnd=json or …cm?cmnd=getState. Channels are zero‑based in current OpenBeken builds, so index 0 is valid. (elektroda.com)

If you share your device model/firmware version, I can tailor a one‑liner and the JSON path you should expect for channel 0 in the getState output.

Disclaimer: The responses provided by artificial intelligence (language model) may be inaccurate and misleading. Elektroda is not responsible for the accuracy, reliability, or completeness of the presented information. All responses should be verified by the user.