TankSync tx

TankSync TX — PCB Design

2-layer solar-powered transmitter board for the TankSync wireless tank monitoring system. Built around the ESP32-C3 SuperMini, RYLR998 LoRa module, and AJ-SR04M ultrasonic sensor. Designed in KiCad 10.0.

Overview

TankSync TX is the transmitter-side PCB of a LoRa-based wireless tank level monitoring system. It measures tank water level using an ultrasonic sensor, monitors battery/solar power via a current sensor, and transmits data wirelessly over 868/915 MHz LoRa to the RX board.

Key features:

• ESP32-C3 SuperMini as the main controller (compact, Wi-Fi + BLE)
• RYLR998 LoRa UART module for long-range wireless communication
• AJ-SR04M waterproof ultrasonic sensor for tank level measurement
• CN3791 MPPT solar charging module for solar panel input
• MT3608 DC-DC boost converter for regulated power supply
• INA219 current/power sensor module for battery monitoring
• WS2812B addressable RGB LED for status indication
• AO3400/AO3401 MOSFETs for power switching
• 1N5819 Schottky diode for reverse polarity protection
• Push button (SW_PUSH_6mm) for manual control
• JST XH connectors for battery and solar panel
• GND copper pour on both layers
• 34 routed nets, 0 unconnected pads

Board Specifications

DRC Notes

The DRC report shows 7 warnings, 0 errors, 0 unconnected pads. All violations are local overrides (non-critical):

These warnings do not affect fabrication or functionality.

Schematic

See /schematic/ folder for schematic export.

Key design decisions:

• LORA_RXD / LORA_TXD routed from ESP32-C3 UART to RYLR998 RXD/TXD pins
• AJ-SR04M ultrasonic sensor connected via TRIG/ECHO GPIO lines
• INA219 current sensor on I2C bus (SCL/SDA) for battery monitoring
• CN3791 MPPT module handles solar panel charging with MPPT algorithm
• MT3608 boost converter steps up battery voltage to regulated supply rail
• Q4, Q5 (AO3401CI-ES) P-channel MOSFETs for load switching
• Q3 (AO3400) N-channel MOSFET for signal switching
• 1N5819 Schottky diode (D1) for reverse polarity protection on power input
• WS2812B (D2) status LED with 470Ω series resistor (R8)
• 100nF decoupling caps on all module power pins

Bill of Materials

Repository Structure

TankSync-tx/
├── README.md
├── LICENSE
├── kicad/
│   ├── TankSync_TX.kicad_pro
│   ├── TankSync_TX.kicad_sch
│   ├── TankSync_TX.kicad_pcb
│   └── TankSync_TX.kicad_prl
├── gerbers/
│   └── TankSync_TX_Gerbers.zip
├── bom/
│   └── TankSync_TX_BOM.csv
└── images/
    └── (schematic, PCB layout, 3D renders)

Gerber Files

The /gerbers/ folder contains the complete Gerber set ready for fabrication:

Recommended fab services: JLCPCB, PCBWay, OSH Park.

Custom Library Dependency

This design uses a custom KiCad component:

• MyLibrary:RYLR998_Castellated_5P — REYAX RYLR998 LoRa module

To open this project in KiCad, add the custom library first: 👉 gargsrishtii/kicad-parts-library

Related Repository

• TankSync RX PCB — gargsrishtii/TankSync-rx

License

This hardware design is released under CERN-OHL-P v2 (Permissive Open Hardware License). Free to use, modify, and manufacture — no share-alike requirement. See LICENSE for full terms.

Part of the TankSync wireless tank monitoring system. Custom KiCad library: gargsrishtii/kicad-parts-library