ESP32 OTA & Firmware Management

VerifiedSafe

Upload, manage, and perform OTA (over-the-air) firmware updates for ESP32 devices. Includes firmware listing, deletion, and complete end-to-end OTA workflow via HTTP.

Sby Skills Guide Bot
DevelopmentIntermediate
406/2/2026
Claude CodeCopilot
#ota#firmware#esp32#over-the-air#workbench

Recommended for

Our review

This skill enables OTA (over-the-air) firmware management for the ESP32 Workbench: uploading, listing, deleting binaries, and triggering updates.

Strengths

  • End-to-end OTA workflow automation via REST API
  • Centralized firmware file storage and management on the workbench
  • Integrates with UDP logs for non-blocking monitoring
  • Supports multipart uploads and proxied HTTP relay to the device

Limitations

  • Requires the device to already be on the WiFi network
  • Cannot be used for blank or bricked devices
  • Depends on the workbench being reachable at the fixed IP 192.168.0.87
When to use it

Use for contactless firmware updates during iterative development cycles on the ESP32 Workbench.

When not to use it

Avoid if the ESP32 lacks built-in OTA support, or if serial flashing is required (e.g., bootloader or partition table updates).

Security analysis

Safe
Quality score90/100

The skill uses curl to interact with a local HTTP API for firmware management. No destructive file operations, exfiltration, or code execution beyond the intended OTA update workflow.

No concerns found

Examples

Upload and trigger OTA update
Upload the file build/firmware.bin to the workbench under project 'sensor', then trigger an OTA update on the ESP32 and monitor progress via UDP logs.
List and delete firmware files
List all uploaded firmware files on the workbench, then delete the file 'old.bin' from project 'sensor'.
Troubleshoot failed OTA
After triggering an OTA update on the ESP32, I see no progress in UDP logs. Help me diagnose and fix the issue.

name: esp32-workbench-ota description: OTA firmware upload, listing, deletion, and over-the-air update for the Universal ESP32 Workbench. Triggers on "OTA", "firmware", "update", "upload", "binary", "over-the-air".

ESP32 OTA & Firmware Repository

Base URL: http://192.168.0.87:8080

When to Use OTA (vs Serial Flashing)

Use OTA when:

  • Device already runs firmware with an OTA HTTP endpoint
  • Device is on the WiFi network (connected to workbench's AP or same LAN)
  • You want to update firmware without blocking the serial port
  • You're doing iterative development (build → upload → trigger → monitor cycle)

Do NOT use OTA when:

  • Device is blank/bricked — use serial flashing (see esp32-workbench-serial-flashing)
  • Device firmware has no OTA support — use serial flashing
  • Device has no WiFi connectivity — use serial flashing
  • You need to flash a bootloader or partition table — only esptool can do this

Endpoints

| Method | Path | Purpose | |--------|------|---------| | POST | /api/firmware/upload | Upload firmware binary (multipart/form-data) | | GET | /api/firmware/list | List all uploaded firmware files | | DELETE | /api/firmware/delete | Delete a firmware file | | GET | /firmware/<project>/<file> | Download URL (ESP32 fetches from here during OTA) |

End-to-End OTA Workflow

Step 1: Upload firmware to workbench

curl -X POST http://192.168.0.87:8080/api/firmware/upload \
  -F "project=my-project" \
  -F "file=@build/firmware.bin"

Response: {"ok": true, "project": "my-project", "filename": "firmware.bin", "size": 456789}

Step 2: Verify upload

curl -s http://192.168.0.87:8080/api/firmware/list | jq .

Step 3: Ensure device is on the network

The device must be able to reach http://192.168.0.87:8080. Use enter-portal to provision if needed (see esp32-workbench-wifi).

Step 4: Clear UDP log buffer (for clean monitoring)

curl -X DELETE http://192.168.0.87:8080/api/udplog

Step 5: Trigger OTA on the ESP32 via HTTP relay

OTA_BODY=$(echo -n '{"url":"http://192.168.0.87:8080/firmware/my-project/firmware.bin"}' | base64)

curl -X POST http://192.168.0.87:8080/api/wifi/http \
  -H 'Content-Type: application/json' \
  -d "{\"method\": \"POST\", \"url\": \"http://192.168.4.2/ota\", \"headers\": {\"Content-Type\": \"application/json\"}, \"body\": \"$OTA_BODY\", \"timeout\": 30}"

Step 6: Monitor OTA progress

# Via UDP logs (preferred — non-blocking)
curl "http://192.168.0.87:8080/api/udplog?limit=50"

# Or via serial monitor (see esp32-workbench-logging)
curl -X POST http://192.168.0.87:8080/api/serial/monitor \
  -H 'Content-Type: application/json' \
  -d '{"slot": "slot-1", "pattern": "OTA.*complete", "timeout": 60}'

Managing Firmware Files

# List all uploaded firmware
curl http://192.168.0.87:8080/api/firmware/list

# Delete a firmware file
curl -X DELETE http://192.168.0.87:8080/api/firmware/delete \
  -H 'Content-Type: application/json' \
  -d '{"project": "my-project", "filename": "firmware.bin"}'

# The download URL for ESP32 to fetch:
# http://192.168.0.87:8080/firmware/<project>/<filename>

Troubleshooting

| Problem | Fix | |---------|-----| | Upload returns "expected multipart/form-data" | Use -F flags (not -d) for multipart upload | | File not in list after upload | Check project/filename; .. and / are rejected | | ESP32 can't download firmware | Device must reach workbench at 192.168.0.87:8080; check WiFi | | OTA trigger times out | Check device's OTA endpoint URL; increase HTTP relay timeout | | No progress in UDP logs | Device may not send UDP logs — check serial monitor instead (see esp32-workbench-logging) | | OTA trigger returns error | Verify device firmware has OTA endpoint; check relay response body |

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