Hi All,
I am using a Mega 2560 and bluetooth to control a MCP4151 Digitial Potentiometer. I have a MCP4151 and a HC-05 (Bluetooth board) on a breadboard, with power coming from the Arduino.
Using this set up, the MCP4151 can provide 1.8V to 5.0V (for some reason, it doesn't go to 0?) but I need to be able to provide 0-12V.
I am not very good with electrical stuff, so I am trying to figure out how I would provide 12V power to the MCP4151 to be able to output up to 12V.
I currently have the following wire setup:
- Pin 1 -> Arduino Pin 53
- Pin 2 -> Arduino Pin 52
- Pin 3 -> Arduino Pin 51
*Pin 4 -> Breadboard Negative
*Pin 5 -> Breadboard Positive
*Pin 6 -> Output (Hydraulic Flow Valve)
*Pin 7 -> Breadboard Negative
*Pin 8 -> Breadboard Positive.
Would it be as simple as changing Pins 5 and 8 to a 12V supply, and Pins 4 and 7 to the Negative of that supply?
Thanks in advance.
MCP4151 Data Sheet
This project is far too customized and particular, to rely on pin lists for a description. Please provide a wiring diagram of all your wiring, and since you say you're not very good with electrical stuff, also close up images of your wiring.
https://forum.arduino.cc/t/how-to-get-the-best-out-of-this-forum/679966
"The language of electronics is a schematic or circuit diagram. Long descriptions of what is connected to what are generally useless. A schematic is a drawing of what connects to what; please make one and photograph it. We don't mind if it's hand drawn, scruffy and does not use the correct symbols. Please don't post Fritzing diagrams. They may look nice but they are very easy to misinterpret."
I don't have any wiring diagrams, nor do I know how to make them. I didn't think it would be necessary though as the only thing I need to know is where to provide 12V to the MCP4151 to get the Output I need.
The LED in these pictures was for testing purposes only.
Then how did you build the circuit?
Guesswork, a bit of googling and trial and error
1 Like
It got me a working prototype, and all I need now is to ramp up the power supply, I just thought I would ask for the correct way to do it before I blow up too many things
Nobody can really offer reliable advice without reliable information. I didn't make this up, it's how the field of electronics works. It's almost impossible to guess how your circuit is connected without a schematic.
To ask how modifications should be done, to an almost unknown circuit, is really not realistic.
You surely know what pen and paper is. It often works well.
Reply: No, You can't apply 12 volt to the analog parts. Max 0.3 above Vdd (5volt max).
How are you measuring that?
Sadly, you have a working prototype that is of no use to you.
Now dig around the analog books to learn about amplifiers… you may need to offset the amplifier output to achieve the 0-12 that you’re looking for.
This isn’t an Arduino problem.
You have your control and the MCP generating a known output voltage
The trick is to get from the datasheet to reality.
Remember too that voltage is only part of the problem.
What are you driving? It may need more current than you’re not currently planning.
Hopefully that makes sense.
After testing the LED (visually seeing the change) I added twin core cable, Red to MCP4151 Pin 6, Black to Breadboard Negative. Then used a Multimeter
Also, if all you are doing is generating a voltage, you should use a DAC instead.
@ aarg
A DAC producing 0 - 12 volt..... Possible? Maybe.
Yes. Try to use pin designations as often as possible. Pin numbers work for helpers knowing the circuit but not else.
Where is the bypass capacitor for the IC? Did you read the data sheet? Section 8.4.1
I read some of the data sheet, admittedly not the whole thing as I didn't understand alot of it.
My employer believes that because I know how to write some extremely basic C++ code, that I can produce all of this with no knowledge, hence why I am struggling here.
So what is a bypass capacitor and why do I need it? (Going to read the section you mentioned now)
