Waveform Generator Design with ESP32
Thought for 1 min 1 sec
To keep the bill-of-materials as small as possible, there are two common approaches:
- Use the ESP32-S2/S3’s built-in 8-bit DAC channels, plus a simple RC reconstruction filter (and optionally an op-amp buffer).
- Add a tiny external SPI DAC (e.g. a 12-bit MCP4921), decoupling caps and a single RC filter (no extra buffer required).
Which would you like to pursue?
- “Built-in DAC” for the absolute minimum part-count (8-bit resolution)
- “External DAC” for higher fidelity (12-bit+) with only a handful more parts
external DAC
Thought for 2 mins 42 sec
Here’s a minimal parts list to pair an external 12-bit SPI DAC with your ESP32 for sine/saw/tri/square/multi-sine generation:
Table
| Ref | Qty | Part | Notes |
|---|---|---|---|
| U1 | 1 | MCP4921-E/SN | 12-bit SPI DAC, SOIC-8 |
| C1 | 1 | 100nF0603 | VDD decoupling (X7R, 50 V) |
| C2 | 1 | GRM21BR61H106KE43L | VDD bulk decoupling, 10 µF 0805 (X5R, 50 V) |
| R1 | 1 | RK73H1JTTD1002F | 10 kΩ 0603, 1% — DAC output filter resistor |
| C3 | 1 | 100nF0603 | Output filter cap (together with R1) |
Next, we need to place the ESP32 itself. Which variant do you prefer?
- ESP32-S2 or ESP32-S3?
- Do you want to use a pre-mounted module (e.g. WROOM/WROVER) or the bare QFN chip?
ESP32-S3 module
ESP32-S3 bare chip
ESP32-S2 module
ESP32-S2 bare chip
