That looks like a nice device. I really like the photo of the back of the board. Someone really thought about that and invented the manufacturing process to make it.
But the Arduino is a PWM controller. You just need the high-power output transistors. The rest of that board is unnecessary. If you can't wait for the correct board (usually called a motor driver) to be shipped to you, you could desolder the chips on that board and connect the Arduino PWM output direct to the output transistors.
I assume that the red board shown in your rough schematic is a DAC, which feeds the opamp.
I would recommend using a separate power supply for the motor controller. Switching noise will effect the Arduino, and maybe even kill it.
I don't understand why the motor controller uses a double stacked pot. The red and black wires from the pot are not making sense to me. Is there a switch built into the pot? You already have a on off switch.
If that really is a double stacked pot you are going to have trouble replacing the pot with an Arduino without understanding why there are two pots. The group of three wires makes sense, the red and black are a mystery to me.
herbschwarz:
Hi All,
Can you use a digital pot?
Herb
sorry no idea what a digital pot is but will google it now
amdkt7:
I assume that the red board shown in your rough schematic is a DAC, which feeds the opamp.
I would recommend using a separate power supply for the motor controller. Switching noise will effect the Arduino, and maybe even kill it.
I don't understand why the motor controller uses a double stacked pot. The red and black wires from the pot are not making sense to me. Is there a switch built into the pot? You already have a on off switch.
If that really is a double stacked pot you are going to have trouble replacing the pot with an Arduino without understanding why there are two pots. The group of three wires makes sense, the red and black are a mystery to me.
the two wires red and black are an on off switch
the pot seems to control the speed.
i did a little more searching and discovered that there is a 555 ic timer for the pwm to the transistors.
ill attach a similar circuit that i think it is but im not sure.
That circuit can only drive the motor in one direction. The controller board you have is more complex, but ultimately uses the same principle.
it has a 3 position switch centre off forward labelled as one and reverse labelled as 2 which pull in relays. i assume they flip the positive and negative terminals around.
I built a circuit like that once to control fan speed. I did use a digital pot in place of the analog pot. I believe I found the range to be limited, or tricky to get right. But in your case the 555 is running on 10v, and digital pots that work at that voltage are harder to find.
I know this part would work with the 555, but it seems like the wrong way to go about it. The whole point of the 555 is to produce the PWM, which the arduino can handle just fine (the frequency is not as has as the fan motor wants, but for most projects it is okay). Your motor might be more demanding than a simple computer fan, hence a 555 to produce the higher PWM rate. I had trouble getting my 555 to go above 20KHZ, the output voltage dropped.
I think the first thing that you need to determine is what your motor actually needs. I don't think you specified what motor you are using, or what you are trying to control. That will determine what direction you need to go, but I am suspecting that you need a different motor controller, one that can take digital commands (I2C perhaps).
But i need some help as the product data sheet doesn't make much sense to me.
i bought the MCP45HV51-104E
I will be connecting to my arduino nano and the speed controller
what do i put on pins
VL
DGND
V+
V-
do i pick one as a power supply or do i need to connect both and if so which way around
i will be using 5v for the nano
and the speed controller will be on 9-13Vdc as the battery drains
This is the way i thought it should be connected. if anything is wrong can you point it out and why
so next time i dont make the same mistake.
1 VL 5v same as arduino uno
2 SCL A4 on arduino uno
3 A1 Output on arduino for address
4 SDA A5 on arduino
5 A0 Output on arduino for address
6 WLAT Not connected
7 NC connected to ground
8 SHDN Not connected
9 DGND Ground
10 V- 0 volts same as speed controller, also connected to ground
11 P0B Potentiometer 0 Terminal B
12 P0W Potentiometer 0 Wiper Terminal
13 P0A Potentiometer 0 Terminal A
14 V+ 9-13vdc supply same speed controller
The pins A0,A1 are used to program the device's address. I would tie both to ground, which I believe will make the device address 0. There is a table that shows how to then address address 0.
The WLAT pin should probably be tied LOW, to ground. Otherwise the values that you write to the device will be not applied until the WLAT pin does go low. It should not be floating, or not connected.
The SHDN pin will need to be tied high to enable the output.
Looks like the rest of the pin assignments are correct, but you will really have to study that datasheet.
Do you have a Arduino library for this device? If not you are going to have to really dig into how to send this thing commands.
If none of those ideas works you can always hotglue the knob to this servo and then use voltage divider feedback and the PulseIn function to measure the pwm output, and control the servo using the Servo() Library
