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GrowSmart Level

GrowSmart Air

Description​

With the GrowSmart Level you never have to worry again about the water level in your hydroponic system and reservoir tank. It uses two hydrostatic pressure sensor that meassure the exact water level, accurate to the milimeter.

Bill of Materials​

  • 2 * TL-136 Liquid Level Sensor (~$25) - get the 0-1m range version
  • 2 * DFRobot Gravity Analog Current to Voltage Converter 4-20mA [SEN0262] (~$5)
  • 1 * DFRobot Gravity I2C ADS1115 16-Bit ADC Module [DFR0553] (~$15)
  • 1 * 12V 6W Power Supply (~$7) - the nearly square "SS-6V12" model, 42x43x21mm (see below)
  • 17 * M3x5x4 heat set insert
  • 10 * M3x6 socket/button head bolt
  • 3 * M3x8 socket head bolt
  • 4 * M3x12 flat head bolt
  • 1 * M3x25 socket head bolt
  • 1 * IEC320 C8 Socket (~$2) - the mountable kind with bolt holes
  • 2 * M3x8 flat head bolts
  • 2 * M3 hex nuts
  • 1 * SparkFun RJ45 Breakout Board (BOB-00719: ~$1) and RJ45 Jack (PRT-00643: ~$2) - not the MagJack version
  • 1 * 8-pin female header
  • 1 * male 8-pin header
  • Optional: 2 * 3-way Wago connector

Electronics

Assembly​

Solder the power input wires of the PSU to the C8 socket. Connect the I2C wires to the RJ45 jack. Connect the cables from each Current to Voltage Converter to the pins of the ADC Module.

To connect the liquid level sensors, use a 3-way Wago connector (or whatever you prefer) to connect the ground wire from each sensor to the ground output wire of the PSU. Then connect the positive wire of each sensor to the (-) terminal of its respective converter board, and use another 3-way Wago connector to connect the positive output wire of the PSU to the (+) terminals of of the converter boards.

If you don't have/like Wago connectors, you basically need to split the each PSU output wire into two, then connect the sensor to ground and the converter (+) terminals to positive.

Cutaway (Please be aware that the male 90° pin headers shown above are the wrong version (bend on short leg).)