https://github.com/customize5773/esp32-dds-signal-generator
https://github.com/customize5773/esp32-dds-signal-generator
Last synced: 10 months ago
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- Host: GitHub
- URL: https://github.com/customize5773/esp32-dds-signal-generator
- Owner: Customize5773
- License: mit
- Created: 2025-06-26T02:23:31.000Z (10 months ago)
- Default Branch: main
- Last Pushed: 2025-06-26T02:55:05.000Z (10 months ago)
- Last Synced: 2025-06-26T03:27:25.001Z (10 months ago)
- Language: C++
- Size: 9.77 KB
- Stars: 0
- Watchers: 0
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# ESP32-DDS-Signal-Generator
## Overview
The ESP32 "Advanced" DDS Signal Generator is a precision waveform generator built around the ESP32 microcontroller. It implements Direct Digital Synthesis (DDS) techniques to produce stable, configurable waveforms with professional-grade features. This project combines hardware design with robust software architecture to create a versatile instrument suitable for electronics testing, education, and embedded systems development.
## Key Features
- **Frequency Range**: 0.01Hz to 5MHz with 0.61Hz resolution at 40kHz sample rate
- **Waveforms**: Sine, Square, Triangle, Sawtooth (256-point precision)
- **Control Interfaces**:
- Rotary encoder with push-button for local control
- Web-based interface via WiFi AP (192.168.4.1)
- OLED display for real-time parameter monitoring
- **Signal Quality**:
- Low-pass filtering with configurable cutoff frequency
- DC offset calibration
- Output buffering with LM358 op-amp
- **Professional Architecture**:
- Modular firmware design with separation of concerns
- Hardware abstraction layer
- Timer-driven sampling for precise timing
- Error handling and input validation
## Hardware Requirements
| Component | Specification | Notes |
|-----------|--------------|-------|
| ESP32 | ESP32-WROOM-32 | DevKitC-V4 recommended |
| DDS Module | AD9833 | With 25MHz crystal |
| Display | 0.96" OLED | I2C SSD1306 128x64 |
| Rotary Encoder | EC11 | With push-button |
| Op-Amp | LM358 | For output buffering |
| Voltage Regulator | LM1117-3.3 | Clean power for analog section |
| Passive Components | Capacitors, Resistors | See BOM for details |
## Setup Instructions
### 1. Hardware Assembly
1. Connect components according to the schematic in `docs/setup_guide.md`
2. Ensure proper power filtering near analog components
3. Verify all connections with multimeter before powering
### 2. Software Installation
```bash
# Clone repository
git clone https://github.com/Customize5773/ESP32-DDS-Signal-Generator.git
# Install required tools
pip install esptool adafruit-ampy
# Deploy firmware
ampy --port /dev/ttyUSB0 put firmware
```
### 3. Initial Configuration
1. Power on the device
2. Connect to WiFi AP: `DDS_Generator` (password: `generate123`)
3. Access web interface at `192.168.4.1`
4. Verify 1kHz sine wave output with oscilloscope
## Usage Examples
### Basic Operation
```python
from dds_engine import DDSEngine
from frequency_controller import FrequencyController
from dac_driver import DACDriver
# Initialize components
dac = DACDriver(pin=25)
freq_ctrl = FrequencyController(sample_rate=40000)
dds = DDSEngine(dac, freq_ctrl)
# Start output
dds.start()
freq_ctrl.set_frequency(1000) # 1kHz
```
### Changing Waveforms
```python
# Available waveforms: 'sine', 'square', 'triangle', 'sawtooth'
dds.set_waveform('triangle')
```
### Frequency Sweep
```python
import time
for freq in range(100, 5001, 100): # 100Hz to 5kHz in 100Hz steps
freq_ctrl.set_frequency(freq)
time.sleep(0.5) # Dwell at each frequency
```
### Web Interface Controls
```html
440Hz Tone
Square Wave
```
## Performance Specifications
| Parameter | Value | Notes |
|-----------|-------|-------|
| Frequency Range | 0.01Hz - 5MHz | Limited by ESP32 processing |
| Frequency Resolution | 0.61Hz | At 40kHz sample rate |
| Amplitude Range | 0-3.3V | Configurable via output stage |
| THD (1kHz sine) | <1% | With proper filtering |
| Phase Noise | -70dBc/Hz @ 1kHz offset | At 1MHz output |
| Sample Rate | Up to 40kHz | MicroPython limitation |
## Calibration
Refer to `/docs/calibration_procedure.md` for:
- Frequency accuracy calibration
- DC offset compensation
- Amplitude flatness correction
- Temperature compensation (advanced)
## License
This project is licensed under the MIT License - see the [LICENSE](LICENSE) file for details.
## Acknowledgements
- ESP32 hardware abstraction based on MicroPython
- DDS algorithm inspiration from Analog Devices AD9833 documentation
- Web interface using MicroPython's AsyncWebServer implementation
## Inspiration
- [AZDelivery](https://www.instructables.com/member/AZDelivery/)