Esp32-S3 Lora Board for messaring water level

Suggested Tags:

ESP32, Lora-Wan, DIY

Description:

Sensor board for measuring the water level in a tank/reservoir. There is a mechanical sensor that wakes up the ESP32 processor via interrupt when the water level falls below the specified level. The water level is then measured with the TL-136 pressure sensor (4-20mA) and sent together with the measured voltages via Lora. The processor then goes back to deep sleep. The board is designed for battery operation using a single Lipo 18650 battery and can be charged by a small solar panel.

Features:

• Optimized for battery operation including Solar Panel for charging
• low sleep current. All Components are switched off during deep sleep
• while sleeping all dependent voltages (12V, I2C, measurement) are switched off
• 12 Volt is created via an SX1308 DC/DC Converter
• single 18650 Lipo battery
• solor charging via small 6V solar panel
• PowerPath: see https://www.youtube.com/watch?v=37kGva3NW8w

Main Components:

• Prozessor: ESP32-S3
• Lora-Wan: RFM95W
• Charging: TP4056, DW01
• DC/DC Converter: HW-688 SX1308
• Pressure Transmitter: TL-136, 0 to 1 Meter, 4-20mA, 12V
• Optional OLED Display: 128x64 supported via I2C bus

Release Notes Version 3.1 (fixes problems of V3.0)

1. 3 Resistors are accidently set to C17414 (10K) instead of their assigned values
   R16, R17:   33K C17633
   R26:           68K, C17801
   R27, R28:   5K1, C27834 
   
   
2. C6, C10, C14: wrong LPSC Partnumber - was C13585 (10uF) instead of ?? (100uF)
   it seam 100uF is not available in C1206 - check if 10uF is enough
   
   
3. Net V12_ENABLE was not connected to ESP32.
   must be connected to GPIO18
   
   
4. Changed value of R24 from 10K to 20K
   
   
5. Add C15 1uF Kondensator betwen VM and Ground of DW01A in start operation - also without Solar-Voltage
   
   
6. If Wifi ist used directly after starting BROWNOUT_RST errors are thrown and a restart loop occurs. It looks like that the supply voltage is not stable enough to support Wifi.
   Using a large 470uF Kondensator parallel to C6 solves the probleme.