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GrowSmart Dosing

GrowSmart Dosing

Description​

The GrowSmart Dosing can be used to pump small doses of pH regulation solutions into your hydroponic system.

You can use them to either manual adjust the pH level of your nutrient solution, or use it together with GrowSmart Water to automatically keep it within a particular range.

Bill of Materials​

  • 2 * 6V Peristaltic Pump for 5*3mm tubes (~$20) - see below for the right model
  • 1 * PCA9685 I2C PWM/Servo Driver (~$10)
  • 2 * MOSFET 5V-36V DC 15A PWM Driver Module (~$5) - see below for the right model
  • 2 * female 4-pin header
  • 2 * male 4-pin header
  • 1 * 230V to 5V 2A Switching Power Supply (~$5) - typically called "S-10-5"
  • 1 * IEC320 C8 Socket (~$2) - the mountable kind with bolt holes
  • 18 * M3x5x4 heat set inserts
  • 14 * M3x6 socket/button head bolts
  • 4 * M3x16 flat head bolts
  • 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 * female 8-pin header
  • 1 * male 8-pin header

Peristaltic Pump: Dosing Pump MOSFET Board: MOSFET Module

Assembly​

Melt the heat set inserts into the Connect the RJ45 pins to the I2C pins of the PWM Driver, and the PWM pins of the PWM Driver to the PWM pins of the MOSFET modules. (It is recommended to use the two pin groups in the middle of the PWM Driver, to not bump into the peristalic pump later on.)

Solder the power wires to the C8 Socket and connect them to the input of the 5V PSU, then connect the output of the 5V PSU to the VIN+/- terminals of the MOSFET modules.

Solder wires to the power pins of the pumps, and connect those wires to OUT+/- terminals on the MOSFET modules.

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