https://github.com/byronap/exciterdriver
Alternator Regulator Field Controller
https://github.com/byronap/exciterdriver
Last synced: 11 months ago
JSON representation
Alternator Regulator Field Controller
- Host: GitHub
- URL: https://github.com/byronap/exciterdriver
- Owner: ByronAP
- License: mit
- Created: 2025-06-10T20:05:35.000Z (12 months ago)
- Default Branch: dev
- Last Pushed: 2025-06-10T23:16:55.000Z (12 months ago)
- Last Synced: 2025-07-18T12:56:50.566Z (11 months ago)
- Language: C++
- Size: 718 KB
- Stars: 0
- Watchers: 0
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
- Code of conduct: CODE_OF_CONDUCT.md
Awesome Lists containing this project
README
# ExciterDriver
An Open-Source Alternator Regulator Field Controller
[](https://github.com/ByronAP/ExciterDriver/actions/workflows/main-pipeline.yml) [](https://github.com/ByronAP/ExciterDriver/releases) [](https://opensource.org/licenses/MIT)
***
**A modern, robust, and fully-featured alternator voltage regulator field controller based on the Arduino Nano platform.**
This project replaces traditional, outdated internal or external alternator regulators with a smart, microcontroller-based system. It offers features like precise voltage control, tachometer-assisted engine state detection, soft-start for smooth engagement, and comprehensive fault detection with onboard diagnostics.
The name "ExciterDriver" comes from its core function: it is a smart **Driver** for the alternator's **Exciter** (or field) coil.
## Features
- **Precise Voltage Regulation:** Utilizes a PID control loop to maintain a stable target voltage (e.g., 14.2V), which is easily configurable.
- **Tachometer-Assisted Logic:** Uses an engine tachometer signal for fast and reliable detection of engine state (running/stopped), with an automatic fallback to voltage-only logic if no tach signal is present.
- **Soft Start:** Gently ramps up the alternator field current upon engine start, preventing sudden mechanical load on the engine and belts.
- **Robust Fault Detection:** Actively monitors for over-voltage, under-voltage, tachometer signal failure, and other fault conditions.
- **Onboard Diagnostics:** A unique "Diagnostic Mode" allows users to retrieve stored fault codes from the previous run cycle by simply using a push-button—no computer required.
- **Hardware Protection:** Designed with real-world automotive electrical systems in mind, with logic to handle signal noise, voltage sags, and other common issues.
- **Configurable & Open Source:** All key parameters (target voltage, PID gains, timings) are easily adjustable in the source code.
## Repository Structure
```
.
├── assets/ # Images and Misc
├── hardware/ # Schematics, PCB layouts, and hardware documentation
├── src/ExciterDriver # Main Arduino source code (ExciterDriver.ino)
├── src/CalibrationHelper # Calibration Arduino source code (CalibrationHelper.ino)
├── CODE_OF_CONDUCT.md # Contributor Code of Conduct
├── CONTRIBUTING.md # Contributor guidelines and style guide
├── LICENSE # MIT License
└── README.md # This file
```
## Hardware Requirements
A detailed schematic can be found in the `hardware/` directory. The core components are:
- **Arduino Nano:** The brain of the system.
- **Logic-Level N-Channel MOSFET:** To control the high-current alternator field coil. A recommended model is the **IRLR3110Z** or similar logic-level FET capable of handling >10A.
- **Voltage Divider:** To safely measure the battery voltage with the Arduino's analog input.
- **R1:** 22kΩ (from Battery+ to A0)
- **R2:** 10kΩ (from A0 to GND)
- **Protection Components:**
- A 5.1V Zener diode and a 100Ω resistor on the analog input pin for over-voltage protection.
- **LEDs and Resistors:** For status, field, and error indicators.
- **Field LED (D10):** Shows the activity of the alternator field.
- **Error LED (D11):** Illuminates when a fault is detected.
- **Diagnostic PIN (A3):** A momentary push-button or jumper connected between pin `A3` and `GND` for accessing the diagnostic mode.
**Important:** Ensure all components share a common ground with the vehicle's chassis and battery.
## Software Setup
1. **Install Arduino IDE:** Download and install the latest version from the [Arduino website](https://www.arduino.cc/en/software).
2. **Open the Sketch:** Open the `src/ExciterDriver/ExciterDriver.ino` file in the Arduino IDE.
3. **Board Selection:** In the IDE, go to `Tools > Board` and select "Arduino Nano".
4. **Processor Selection:** Go to `Tools > Processor` and select "ATmega328P". Depending on your Nano clone, you may need to select "ATmega328P (Old Bootloader)".
5. **Upload:** Connect your Arduino Nano via USB and upload the sketch.
### Initial Calibration (Recommended But Not Required)
For maximum accuracy, the voltage sensing circuit should be calibrated to your specific components using 2 points.
1. **Upload the Calibration Sketch:** A helper sketch for calibration can be found in the `src/CalibrationHelper/` directory.
2. **Apply Known Voltages:** Using a variable bench power supply and a trusted multimeter, apply two known voltages (e.g., 12.0V and 14.5V) to the regulator's input.
3. **Record ADC Values:** Note the raw ADC values reported by the calibration sketch for each voltage point.
4. **Update `ExciterDriver.ino`:** Enter your measured values into the `VOLTAGE CALIBRATION & REGULATION` section at the top of the main source file.
```cpp
// Update these values with your specific bench measurements.
const float CAL_LOW_VOLTS = 12.001;
const int CAL_LOW_ADC = 742;
const float CAL_HIGH_VOLTS = 14.499;
const int CAL_HIGH_ADC = 854;
```
## Using the Onboard Diagnostics
This system can store fault codes from its last run cycle. To retrieve them:
1. **Power Down:** Ensure the device is completely powered off.
2. **Press and Hold:** Connect the diagnostic pin `A3` or button to ground.
3. **Power On:** While still connected to ground, apply power to the device.
4. **Observe the Error LED:** The device will now enter Diagnostic Mode. The `Error LED` (D11) will blink to indicate any stored fault codes.
**Fault Codes:**
- **1 Blink:** Over-Voltage Fault
- **2 Blinks:** Under-Voltage Fault (while running)
- **3 Blinks:** Alternator Probing Timeout
- **4 Blinks:** Tachometer Signal Failure
If multiple faults are stored, the system will blink the first code, pause for 2 seconds, blink the next code, and so on. If no faults are found, the Error LED will turn on solid for 2 seconds.
The device will repeat the sequence every 5 seconds until it is power-cycled.
**Normal Operation:** To run the regulator normally, simply power it on *without* grounding the diagnostic pin or button. This will clear the fault log from the previous run and begin normal operation.
## Contributing
Contributions are welcome! Please feel free to open an issue to report bugs or suggest features. If you would like to contribute code, please fork the repository and submit a pull request.
Please read our [CONTRIBUTING.md](CONTRIBUTING.md) before contributing.
## License
This project is licensed under the MIT License - see the [LICENSE](LICENSE) file for details.