I am working on a strain gauge load sensor. And I want to do a signal processing by a card.
The program I want to do can be done easily on arduino.
The sensor will use a Wheatstone bridge giving me a voltage in mV / V (5mV if powered in 5V)
Voltage rather weak and I will have to use a card to amplify the signal (for example an HX711)
And then I want to get a signal out of the arduino. However arduino cards only offer PWM outputs. While I would need an analog signal.
Do you know a digital to analog converter that adapts well to the arduino PWM? Being a measurement of precision it would be necessary that the converter makes it possible to have a signal very close to the average signal sent by the PWM (<0.2% of difference).
Thank you for your answer.
I need between 2 and 6 analog outputs and these cards offer only one. That's why I planned to use the PWM.
I think to make a RC filter, but I wondered if there was not a filter already adapted and optimized for the arduino?
I think to make a RC filter, but I wondered if there was not a filter already adapted and optimized for the arduino?
No, because the output voltage depends strongly on the load.
And then I want to get a signal out of the arduino.
There are MUCH better ways of doing this than using the Arduino simply as a DC amplifier. Please explain why you think you need to use analog voltage output.
You have started well with specifying the output parameters required. But we need a lot more...
You said max ripple is 0.2%. Percent of what? What is the voltage range of the output?
Next most important is the speed or frequency response of the output. If you find a good tutorial online about using RC filters on PWM output, you should see that you can achieve any ripple specification by just using a very slow filter.
If you have an HX711 then it outputs digital data at extremely high resolution. Turning that back into analog is like watching a TV program on the radio. You should use the Arduino to send the digital data directly to the final analysis stage.