Onboard Gateway | Hackaday Dream Team 2020

The Onboard Gateway is a 134.11 mm x 62.48 mm PCB that integrates the 3 main components (ESP32, LoRa and USB LiIon/LiPoly charger).

Main Components

Main components of the Onboard Gateway v1.0.

Sources:

• ESP32-DEVKITC-32D
• RFM95W LoRa Radio
• USB LiIon/LiPoly charger

Schematic

Schematic of the Onboard Gateway v1.0.

For more information about the design check the original post in the project's page.

Layout

PCB Layout of the Onboard Gateway v1.0.

PCB

PCB Design: Front and Back.

Assembly

Components of the Onboard Gateway v1.0.

Components List:

1. TERM BLK 2P SIDE ENT 5.08MM PCB
2. CONN HEADER R/A 2POS 2.5MM
3. CONN HEADER VERT 2POS 2.54MM
4. CONN HEADER VERT 2POS 2.54MM
5. CONN HDR 6POS 0.1 TIN PCB
6. 2POS JST cable (included in the USB LiIon/LiPoly charger)
7. USB LiIon/LiPoly charger
8. PCB Onboard Gateway V1.0
9. CONN HEADER VERT 2POS 2.54MM
10. RES 249 OHM 1/4W 1% AXIAL
11. RES 249 OHM 1/4W 1% AXIAL
12. TERM BLK 2P SIDE ENT 5.08MM PCB
13. CONN HEADER VERT 6POS 2.54MM
14. CONN HDR 2POS 0.1 GOLD PCB
15. CONN HEADER VERT 3POS 2.54MM
16. CONN JUMPER SHORTING .100" GOLD
17. CONN HDR 19POS 0.1 TIN PCB
18. ESP32-DEVKITC-32D
19. CONN HDR 19POS 0.1 TIN PCB
20. CONN HDR 16POS 0.1 TIN PCB
21. CONN HDR 12POS 0.1 TIN PCB (I used 2 CONN HDR 6POS 0.1 TIN PCB in the image)
22. CONN HDR 9POS 0.1 GOLD PCB
23. CONN HEADER VERT 2POS 2.54MM
24. CONN HEADER VERT 2POS 2.54MM
25. CONN HEADER VERT 2POS 2.54MM
26. CONN HEADER VERT 2POS 2.54MM
27. RES 100 OHM 3W 5% AXIAL
28. RES 100 OHM 3W 5% AXIAL
29. RES 100 OHM 3W 5% AXIAL
30. RES 100 OHM 3W 5% AXIAL
31. CONN HDR 5POS 0.1 GOLD PCB
32. RFM95W LoRa Radio
33. CONN HEADER VERT 16POS 2.54MM (included in RFM95W LoRa Radio)

For a detailed Bill of Materials visit the following post.

For a detailed explanation about the soldering and assembly procedure visit the following post.

Wiring Diagrams

The following diagram presents the physical connections of the different boards and components of the Onboard Gateway, that includes:

• 3.7V 1 Cell Battery
• Leds (Charge, Done and 4 Miscellaneous)
• PCB Board for the Onboard Gateway V1.0
• 5V Charger (only used to charge the battery)
• Micro USB Breakout Board
• Switch

Wiring diagram for the Onboard Gateway v1.0.

  Firmware

The Onboard Gateway is the topside unit — it stays with the operator and is a hand‑held LoRa link to a deployed buoy. Its ESP32 firmware mirrors the buoy firmware:

• Captive Wi‑Fi UI — WiFi.softAP() access point EJA_Onboard_Gateway, a DNSServer mapping www.onboard_gateway.eja to the ESP32, and an ESPAsyncWebServer serving the UI from SPIFFS with OTA at /update.
• LoRa link — RFM95W at 915 MHz (CS GPIO2, RST GPIO15, IRQ GPIO13). The gateway has no GPS of its own — the position it shows is the buoy's, received over LoRa. Setting a timer sends it to the buoy and only shows the countdown once the buoy confirms; that countdown is an estimate of the one running on the buoy.
• Status LEDs — LED1 (GPIO22) LoRa RX, LED2 (GPIO5) LoRa TX, LED3 (GPIO16) Wi‑Fi client connected, LED4 (GPIO17) the web‑controllable test LED.

  User Interface

For more information about the GUI visit the following post.

Future Improvements

For more information about the recommended future improvements for the electronic design visit the following post.