Mixer3000 is a system capable of measuring weight and temperature, pumping and mixing water, and lifting and lowering a container. All of these capabilities can be used in real time with an Arduino Nano (or UNO) and respective commands.

Hardware

• Arduino Nano or UNO
• HX711
• A4988 (2 units)
• L293D
• DS18B20
• HC020K
• HC-05

Components

Arduino Nano (MCU)	HX711 (Load Cell)	A4988 (Step 1)	A4988 (Step 2)	L293D (Pump)	DS18B20 (Temperature)	HC020K (Encoder)	HC-05 (Bluetooth)
A0	DOUT	-	-	-	-	-	-
A1	CLK	-	-	-	-	-	-
D2	-	STEP	-	-	-	-	-
D3	-	-	STEP	-	-	-	-
D4	-	-	DIR	-	-	-	-
D5	-	DIR	-	-	-	-	-
D6	-	ENA	-	-	-	-	-
D7	-	-	-	-	-	DOUT	-
D8	-	-	ENA	-	-	-	-
D9	-	-	-	PIN 1	-	-	-
D10	-	-	-	PIN 2	-	-	-
D11	-	-	-	-	DOUT	-	-
RX	-	-	-	-	-	-	TX
TX	-	-	-	-	-	-	RX

Notes

• Step motor 1 is used for mixing and Step motor 2 is used for lifting and lowering the container.
• HC-05 is connected directly to the serial communications ports of the Arduino. Uploading code into the Arduino will fail when HC-05 is connected.
• DS18B20 has a slow refresh rate, so code code slows down when it's activated.
• Load cell, Pump and Temperature devices are calibrated. However, it's recommended to re-calibrate them.
• Code can run without calibration equations.
• Start position of Step motor 2 is defined as the position it's in when the Arduino turns on or resets.

Commands

Data is received like an 5-bit int data type value. The first 2 bits, known as dataCode, define the function to execute. Last 3 bits, known as dataValue, define the input value when needed (only for functions 10, 20 and 30).

• 10: Load cell calibration. Receives KNOWN_WEIGHT as dataValue to calibrate.
• 11: Load cell tares 100 times.
• 20: Pump turns on with a 125 PWM and defines reference weight as dataValue. Up to this value the system will pump water, when weight gets to that reference point pumping will stop.
• 21: Turns pump off.
• 30: Step motor 1 receives mixing value for PWM as dataValue.
• 31: Turns step motor 1 off.
• 40: Lifts down container.
• 41: Lifts up container.
• 99: Stops everything and returns height to start position.