ESP32-S3 TinyML Architect Dual LX7 @ 240MHz

Private Edge Person Detection vs Cloud Computer Vision Budget Simulator

Local Inference Latency
95 ms
15-18 FPS (ESP-DL)
Internal SRAM Used / Free
292 KB / 220 KB
Safe (Fits internal SRAM)
2000mAh Battery Longevity
182 days
PIR Wake (50 wakes/day)
3-Year Cloud TCO Savings
$347.64
$12 BOM vs $9.99/mo Cloud
Deployment Hardware Matrix S3-WROOM-1
Model Backbone ~250K params
Input Tensor Resolution 9,216 px
Quantization Format ~300KB Flash
Kernel Acceleration Xtensa S3 SIMD
WiFi / MQTT Radio Stack +0KB SRAM
Power & Trigger Strategy
LiPo Battery Capacity 2000 mAh
Cloud Vision Plan (Monthly) $9.99 / mo
Internal 512KB SRAM Memory Pool Safe (Fits internal SRAM)
Used: 292 KB / 512 KB Free Heap: 220 KB
Tensor Arena (140 KB)
TFLM Runtime (22 KB)
App Logic (30 KB)
Camera DMA & Core (100 KB)
WiFi/MQTT (0 KB)
Free SRAM (220 KB)
* Note: Keeping the tensor arena inside internal SRAM ensures full 240MHz zero-wait-state bus bandwidth. Placing it in external PSRAM collapses FPS to ~3 FPS. Frame buffer (QVGA 320x240 RGB565 = ~150KB) safely resides in 8MB PSRAM.
Pipeline Latency Waterfall (Person Detection) Local is 5.1x Faster
⚡ ESP32-S3 Local Edge Pipeline 95 ms
OV2640 DMA 25ms
Downsample 15ms
ESP-DL Invoke 53ms
GPIO 2ms
PSRAM Overwritten in 100ms Zero Hallway Frames Leave Premise
☁️ Cloud-Tethered Vision Stream 480 ms
JPEG 75ms
WiFi TX 135ms
Cloud Queue 185ms
Push ACK 85ms
Microwave interference spikes to 2,500ms Uncompressed raw imagery stored on remote servers
Visual Wake Words Optical Horizon At 3.0m: Person Resolves Clearly
OV2640 Lens
🚶
54 px high
3.0 m
3.0 meters (Optimal): Person silhouette spans ~54 vertical pixels on 96x96 sensor. Head, torso, and limb proportions readily clear binary classification threshold (>10 logit).
36-Month Cost of Ownership (BOM vs Cloud API) Saves $347.64
Expense Item ESP32-S3 Local Edge Cloud Camera Stream
Hardware BOM (Camera + DevKit) $12.00 (One-time) $49.99 (Proprietary)
Vision Subscription (36 mo @ $9.99) $0.00 $359.64
Bandwidth Egress & Storage $0.00 (0 MB/mo) $0.00 (Included)
Net 36-Month Cost $12.00 $409.63
Generated ESP-IDF / Arduino C++ Header