This is a circuit will a number of sensors that will be used for a bioreactor

Monitoring ambient temperature and humidity

  • Used the BME280 adafruit sensor 

  • SPI bus protocol was used to connect the sensor the Raspberry pi 3

  • Vin from the sensor was connected to 5V

  • GND was connect to ground

  • SCK was connected to SPI SCLK (pin 23)

  • SDO was connected to MISO (pin 21)

  • SDI was connected to MOSI (pin 19)

  • CS (chip select) was connected to GPIO 29 (pin 40)

  • Note CS must be set to 0 to enable the chip


Monitoring pH

  • The EZO embedded pH circuit was connected to the Raspberry pie 

  • The EZO Carrier board will be used to connect the embedded pH with the pH probe from this kit

  • The EZO carrier board will connect to the embedded pH circuit through PGND and PRB

  • The I2C protocol was used to connect the sensor to RP 3

  • VCC was connected to 5v with GND was grounded

  • TX was connected to SDA0 (pin 27)

  • RX was connected to SCL0 (pin 28)

  • Used I2C address will be 0X63


Controlling pH 

  • Two peristaltic pump will be connected to the system (one for acidic solution, one for basic solution)

  • DC motors were used in the circuit to represent the peristaltic pump

  • The ULN2003A transistors array will be used to connect the DC motor to the raspberry pi

  • GPIO ports were used to connect the Raspberry Pi to the the ULN2003A

  • The Raspberry Pi ports controlling motor1 are GPIO0 (pin 11)  and GPIO2 (pin 13)

  • The Raspberry Pi ports controlling motor2 are GPIO3 (pin 15)  and GPIO10 (pin 24)


Monitoring water oxygen  

  • THe EZO D.O. embedded circuit will be connect to the Raspberry pie

  • The gravity analog D.O. meter will be used to connect the water oxygen probe to the embedded D.O. circuit

  • The UART bus protocol will be used 

  • VCC is connect to 5v and GND is  grounded

  • PRB and PGND are connected to the gravity analog D.O meter

  • TX is connected to RXD (pin 10)

  • RX is connected to TXD (pin 8)

  • Default baud is at 9600


Monitoring growth

  • A 633nm LED will be connected to VCC and GND (might need to add a resistor in the circuit) - no need to buy the LED, they are easily accessible, just like wires

  • The TSL2591 light sensor will be used 

  • I2C protocol will be used to connect the sensor to the Raspberry Pi

  • Vin will be connected to 5V and GND to ground

  • SCL will be connected to SCL1 (pin 5)

  • SDA will be connected to SDA1 (pin 3)

  • The I2C address will be 0X29

Controlling growth

  • A peristaltic pump system, like the one used to control pH, will be used 

  • The Raspberry Pi ports that will connect to the motor will be GPIO 27(pin 36) and GPIO 26 (pin 32)