Hello everyone .
Doing a little hobby project for my aquarium , and i've tinkered a bit with arduino earlier. Flashing lights and some sound and stuff . I want to build an automatic feeder for my aquarium ; thus getting the food from one container to the aquarium using water. The technical , the actual mechanism , i have that under control. But can I run a 270oz NEMA 23 stepper bipolar AND a 12 volt bilge pump by using just one Uno ? The program will be like this: run 1/4 turn, stop motor for x seconds, run motor 1/4 turn, stop motor, start the pump, run pump for x sesongs, stop the pump. My plan is to use a car battery with a solarpanel since I do not have unlimited power available at the location for the aquarium yet.
I'm thinking of using a relay to turn on and of the bilgepump.
I'll Hope someone can help.
Building Log will be published when I'm starting manifacturing.
No reason that you can't do what you want. The stepper will need a proper driver. I can't help much with the selection of the driver. If you post a datasheet or more detailed specs for the stepper, I am sure that one of the members can help with that. As for the pump, specs needed for that, too (most significant is stall current). A MOSFET or solid state relay might be a better choice of a driver for the pump since you are running from a battery. A regular relay will need (substantial?) coil current while energized, while a SSR or MOSFET take much less to stay turned on.
As far as the Arduino is concerned the size of the motors is irrelevant. The Arduino is only providing a control signal. It is not providing power for the motors.
I have been looking at different components, and i have decided on a preliminary list. What do you think about this's configuration? The project wil be powered by a 12V battery in the beginning, so I'll have to reduce the voltage from the battery to power the servo and UNO, but I'll deal with that matter later on.
Specification for bilge pump:
Capacity: 32L / min
Voltage: 12 Volt
Current: 2.5 A
Fuse: 4 A
Specification servo:
Speed 6 volts: 0,2sec / 60 degrees
Speed 7.2 volts: 0,18sec / 60 degrees
Torque 6 volts: 33.5 kg / cm
Torque7.2 volts: 39.8 kg / cm
I will control the pump with a MOSFET IRF520 with the following specifications:
Voltage: 3.3V, 5V
Ports: Digital Level
Output load voltage: 0-24 V
Output load current: <5A
But then it gets a bit challenging for electronics engineers in me. Will I have to put on a potentiometer on the servo so that it will know where it is?
Can all this be connected directly to UNO as it stands today or do I have to expand it with a shift register?
If there is someone who has any input or comments to my choice of components I'd be very happy.
reduce the voltage from the battery to power the servo and UNO
Servo, yes. Uno will run from 12V. Regulator may get warm if driving lots of LEDs or some other power hungry devices on IO pins.
Use a better MOSFET - AOI514 - to sink current thru the pump
Servo moves to position the Servo.h library commands it to and has internal stuff to monitor its position.
Uno can control all with the MOSFET for the pump. Put a 150 to 220 ohm resistor between Arduino pin and MOSFET gate.