I have been using Phidgets and associated sensors for my hydroponics and irrigation software at peterphrastus.com. I have been asked if I can look into using arduinos. I cannot seem to find temp, humidity and other sensors for the arduino but the Phidget sensors use a 5v reference. Can the Phidget sensors be used directly in the arduino by using the arduino’s 5 volt supply? Can the arduino be used with VB.Net in a fairly straightforward manner (i.e. emulate a Phidget in the PC software and query the arduino for sensor values)? Can multiple arduinos be addressed from the same PC because there are insufficient analog inputs on the arduino for my apps? Many thanks for any help to an arduino newbie.
Thanks Richard
Phidgets have the concept ratiometric/non-ratiometric relative to some sensors. Does this concept exist in the arduino?
Another beginner question. If I build an interface to the mega, would the same code work if an end user specifies an arduino with less I/O? I am assuming yes because the interface is just serial bytes. All this would do is give the end users less capability from my software which may be just fine for them. I would give them the ability to assign the I/O ports to whatever functions they wish to have.
I see. I have to write two bits of code: one for the particular arduino and one for my vb/net app. This is a bit different than the Phidget environment. I now need to do some reading rather than overstaying my welcome here. Is there a good reference book around or site with reference material? Thanks to all for you help.
Generally speaking, the Arduino code is portable between Arduino models. As you indicate, some of the pin assignments may vary from model to model. Also, some differences may be found when using different AVR chipsets. So you may need minor changes to the code to make it work on another Arduino.
You may find yourself offloading much of your logic onto the Arduino, which can be standalone.
Arduino is open source, you can find the code reference at arduino.cc/en/Reference/HomePage
There are also PDF e-books that can be found online with a bit of searching and forums that may help in your development. Overall Arduino is very fast to learn/implement.
Pretty much any sensor that functions at 5V will work with the Arduino. Just have a look at the Sensors Sections in order to find sensors tat suite your needs. Also, in order to directly interface them with the Arduino you might want to used some interface shields such as the DFRobot I/O Expansion, the SeeedStudio Electronic Brick Shield, the GHI Component Shield.
Ratiometric means that the output voltages are a function of the input voltages. This applies to the Arduino to, but since the input is always 5V you will not have to worry about it.
Finally, if you need very many inputs and outputs, we recommend using the Arduino Mega would be a good idea, as pointed out by Richard. In order to easily connect sensors to the Mega, you might want to use the DFRobot MEGA Sensor Expansion Shield.