No, all you need is the suggested motor driver. Why are you opposed to letting the Arduino do the motor speed control? Currently you are only using the Arduino to monitor battery voltage and make a decision to run or not run a motor based on that voltage. Why not use the Arduino to also control the motor speed? Your motor controller is designed for a PWM (speed) control input. The motor controller should also handle the motor current so why not take advantage of that?So I would need a better speed controller that can handle a higher amp
This! You just connect the wiper of a pot to an analog in pin of your Arduino and you have your physical speed controller. Unfortunately I no longer have any of that pictorial software on this computer. I normally just do schematics. Let me see what I can find.A potentiometer connected to an analogue input pin of the Arduino will be a physical speed controller.
I gathered as much but the issue right now is you do not need an added speed controller since your Arduino can control motor speed with a single external pot and also monitor battery voltage to allow the motor to be run or not run based on the battery voltage. The same decision to have a motor run or not run could be made with a simple Window Comparator circuit and a single MOSFET used as a switch. Why even use a micro-controller like an Arduino? The merit to using a uC is what I mentioned earlier as to Hysteresis which I can also do with a comparator circuit. The Arduino (uC) also offers a PWM covering the motor speed which you seem to want.I use ms paint to make the picture
We will take the analog input to your Arduino from the pot and convert the 0 to 5 volts in to a PWM out. We will run the battery voltage into another analog in channel after we divide by 3 as I mentioned earlier and let the Arduino monitor that More on all of that later.The potentiometer is wired between 0V (Gnd - left pin) and 5V (right pin) and the wiper (center) goes to an analogue pin. This means that at one end (anti clockwise) the wiper is at 0V and at the other end it's 5V.