ESP32 OTA & Firmware Management

VerifiedSafe

Manage ESP32 firmware through the workbench web interface: upload, list, and delete binary files. Trigger over-the-air updates on WiFi-connected devices, enabling iterative development without blocking the serial port.

Sby Skills Guide Bot
DevelopmentIntermediate
906/2/2026
Claude Code
#ota#firmware#esp32#over-the-air-update#workbench

Recommended for

Our review

This skill manages over-the-air firmware updates for an ESP32 workbench server, including uploading, listing, deleting firmware files, and triggering OTA updates on devices.

Strengths

  • Enables iterative development without serial port blocking
  • Provides a complete workflow from upload to monitoring
  • Includes troubleshooting guidance for common issues
  • Supports both HTTP relay and UDP log monitoring

Limitations

  • Requires device to have OTA support and network connectivity
  • Cannot flash bootloaders or partition tables
  • Depends on a fixed workbench IP address (192.168.0.87)
When to use it

Use when you need to update firmware on an ESP32 that already runs OTA-capable firmware and is on the same network as the workbench.

When not to use it

Do not use if the device is bricked, lacks OTA support, or if you need to flash low-level firmware components.

Security analysis

Safe
Quality score92/100

The skill instructs HTTP requests (curl) to a local workbench server for legitimate OTA firmware management. No destructive commands, exfiltration, or obfuscation beyond trivial base64 encoding for payload transmission. Risks are minimal as all actions target the user's own devices and network.

No concerns found

Examples

Upload firmware to workbench
Upload the firmware binary from build/firmware.bin to the ESP32 workbench for project 'sensor-v2'.
Trigger OTA update on an ESP32
Trigger an OTA update on the ESP32 at http://192.168.4.2/ota with firmware URL http://192.168.0.87:8080/firmware/sensor-v2/firmware.bin and monitor the progress via UDP logs.
List and delete firmware files
List all firmware files uploaded to the workbench, then delete the file named 'old-firmware.bin' from project 'sensor-v2'.

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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