https://github.com/mondaladi/smart-server-power_switch
Computer power switch automation for remote control and monitoring over the internet using MQTT on ESP8266 via a web app.
https://github.com/mondaladi/smart-server-power_switch
esp8266 hivemq-cloud mqtt taskscheduling
Last synced: 22 days ago
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Computer power switch automation for remote control and monitoring over the internet using MQTT on ESP8266 via a web app.
- Host: GitHub
- URL: https://github.com/mondaladi/smart-server-power_switch
- Owner: mondaladi
- License: mit
- Created: 2025-03-01T17:38:51.000Z (about 1 year ago)
- Default Branch: main
- Last Pushed: 2025-03-02T06:43:27.000Z (about 1 year ago)
- Last Synced: 2025-03-20T00:14:20.211Z (about 1 year ago)
- Topics: esp8266, hivemq-cloud, mqtt, taskscheduling
- Language: HTML
- Homepage: https://www.instructables.com/Turn-Your-Windows-PC-Into-a-Home-Server-in-Just-30/
- Size: 148 KB
- Stars: 0
- Watchers: 0
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# Smart Server Power Switch
## Purpose
This project allows remote power control of a home server via a web app, reducing unnecessary power consumption. Instead of switching the AC power, a NodeMCU (ESP8266) electronically simulates the motherboard’s power button press using a BC547 transistor. Automating the AC power switch was avoided due to challenges in ensuring the server turns on automatically when power is applied.
## Working
- The ESP8266 connects to WiFi and an MQTT broker (HiveMQ Cloud), listening for a `"power"` command via MQTT. When received, it triggers the BC547 transistor, momentarily shorting the motherboard’s power switch terminals to simulate a physical button press.
- The motherboard’s power LED voltage is monitored using the ESP8266's ADC (`A0`) via a voltage divider to determine if the server is ON or OFF, providing real-time status feedback. This data is sent via MQTT and displayed on the web app.
- The ESP8266 also sends a heartbeat pulse every 3 seconds to indicate its online status.
- A manual push button allows local power control in both offline and online modes.
- The computer's actual blue power LED is wired to the ESP8266 instead of the motherboard, reflecting the real-time power status while its original terminals are rerouted through the ESP8266.
**Note:** I have used the **TaskScheduler library** to ensure that all functions/tasks run **in parallel and smoothly without blocking execution**. Initially, I attempted the usual `millis()`-based approach, but it did not work perfectly in all scenarios.
## Web App
The web app is hosted on **Netlify** and provides:
- Remote control of the server power switch.
- Real-time ESP8266 status (Online/Offline).
- Live server power status (ON/OFF).
## Connections
| Component | ESP8266 Pin | Description |
|----------------------------------------------------|:-------------------:|-----------------------------------------------|
| BC547 Transistor (Base) | D2 | Controls the motherboard power switch |
| Motherboard's Power Switch Terminal | Collector & Emitter | Simulates button press |
| Motherboard's Power LED pins (via Voltage Divider) | A0 | Reads server power status |
| Manual Push Button | D5 | Local power control |
| Power LED | D7 | For indicating the power status |
## Future Improvements
- **Logs & History Tracking** – The web app will store timestamps of server ON/OFF events and ESP8266 disconnections/reconnections for historical tracking.
- **Live Power Monitoring** – A current sensor will measure real-time power consumption, displaying it on the web app for better power management and anomaly detection.
## License
This project is licensed under the [MIT License](LICENSE).