Hardware Guide
The ESP32-C3 handles predictive maintenance classification with TFLite Micro, though its single RISC-V core at 160 MHz requires careful resource management. At $1-3 per chip with Wi-Fi, it is the budget option for vibration-based monitoring when you need wireless connectivity.
| Spec | ESP32-C3 |
|---|---|
| Processor | Single-core RISC-V @ 160 MHz |
| SRAM | 400 KB |
| Flash | Up to 4 MB (external) |
| Key Features | RISC-V architecture, Ultra-low cost, Hardware crypto acceleration |
| Connectivity | Wi-Fi 802.11 b/g/n, Bluetooth 5.0 LE |
| Price Range | $1 - $3 (chip), $4 - $10 (dev board) |
The ESP32-C3's 400 KB SRAM exceeds the 64 KB minimum for predictive maintenance models by 6x, so memory is not the constraint. The limitation is the single-core RISC-V at 160 MHz: vibration-based predictive maintenance requires simultaneous sensor polling at high sample rates (200-400 Hz) and inference. On a single core, you must interleave these operations carefully using FreeRTOS task priorities. Inference itself is fast for a 30 KB vibration classifier, but dropped sensor samples during inference windows can degrade classification accuracy. This is manageable with ring buffers and DMA-based sensor reads. TFLite Micro's RISC-V support is solid since ESP-IDF v5.0. For cost-sensitive deployments where you need hundreds of nodes, the ESP32-C3's $1-3 price point makes the engineering tradeoff worthwhile compared to the dual-core ESP32 at $2-5.
Configure ESP-IDF for ESP32-C3
Install ESP-IDF v5.1+ and set the target: idf.py set-target esp32c3. Add the tflite-micro-esp-examples component for TFLite Micro RISC-V support.
Set up DMA-based sensor acquisition
Configure the I2C or ADC peripheral with DMA to sample the accelerometer at 200-400 Hz without CPU involvement. Use a ring buffer to prevent data loss during inference cycles. This is critical on the single-core C3.
Train a vibration classifier
Use TensorFlow to train a small classifier (2-3 Conv1D layers) on FFT features from vibration data. Target model size under 30 KB after int8 quantization. Keep the tensor arena under 20 KB.
Implement duty-cycled monitoring
Run inference on sensor windows (e.g., 1 second of data every 10 seconds). Between windows, the C3 can enter light sleep. Report results via MQTT. Set FreeRTOS task priorities so sensor sampling always preempts inference.
Dual-core eliminates the single-core scheduling challenge. 520 KB SRAM with Edge Impulse's optimized pipeline. Slightly higher cost ($2-5 chip) but simpler development.
Ultra-low-power for battery-operated monitoring. 80 MHz Cortex-M4 with DSP instructions. No Wi-Fi but extreme power efficiency (< 100 nA shutdown).
Deploy predictive maintenance to ESP32-C3 fleets — design once, push to hundreds of nodes from a visual workflow.
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