I am trying to make a system of pressure control for microfluidics experiments. I'm going to use the Arduino Due to do that (because I need the analog outputs). However, the other components which rely on it need higher voltage than 3.3V, the maximum delivered by Arduino.
I am looking for a shield which allows us to use components working at 5V and 6V, maybe 5V and 12V. Power is not a problem because these components don't need more than 70mA.
However, I don't know many things about electronics and I frequently can't understand everything.
Moreover, instead of using a shield, I have thought about making a circuit including a transistor or an Integrated Circuit, but I still lack the knowledge about electronics.
I wonder if somebody here has ever tried to have an amplified voltage? Furthermore, I need guidance about electronics and shields.
For higher voltages you will need to implement an additional PSU.
You could for example use an additional PSU delivering 12V and feed this voltage to the Arduinos Vin pin from the shield instead of using its wallwart jack to power it. The Due then converts the 12V to 5V and 3.3V.
So you need an additional PSU delivering 12V and a matching wallwart to power it.
For 6V things get a little bit more complicated, because if you feed 6V to the Arduinos Vin pin, there is not enough voltage for the Arduinos voltage regulator to work properly. You would have to add an additional voltage regulation circuit supplying 6V to the shield then.
Another approach if you only need 6V, 5V and 3.3V:
Use a 9V or 12V wallwart. Power the Arduino AND an additional power regulation circuit generating 6V. Get the 5V and 3.3V from the corresponding pins of the Arduino.
Thank you for your answer, but I have a question. When you say that Due delivers 5V... I think I don't understand this text :
"The microcontroller mounted on the Arduino Due runs at 3.3V, this means that you can power your sensors and drive your actuartors only with 3.3V. Connecting higher voltages, like the 5V commonly used with the other Arduino boards will damage the Due.
The board can take power from the USB connectors or the DC plug. If using the DC connector, supply a voltage between 7V and 12V." (from this page :http://arduino.cc/en/Guide/ArduinoDue )
So, does it mean that Due doesn't support 5V (only 3.3V input voltage), but delivers 5V ? How many pins could give this voltage ? What are the components which permit to Due to transform 3.3V to 5V ?
No you are quite right. The Due only delvers 3v3 on the outputs. More than that the analogue outputs and some digital ones must not supply more than 3mA.
The Due is not a beginners board as you need to know a lot about level conversion before you can interface it to many things.
Maybe tomtrialanderror does not know what the word "deliver" actually means.
I suspect he was confusing it with the Arduino Mega.
Assuming you just need reference voltages, you can get analog outputs by using digital potentiometers as voltage dividers.
Note that if you're planning to draw current from the analog output, that's going to be a problem - analog outputs (either from digipots, or DACs in the Due or other MCUs) can't handle very much current. In many cases where you need some current, though, PWM can be used, instead of a true analog output.