Data Acquisition

Hi, all.

I'm new to the forums, and Arduino, and thought I'd asked a resource/use question to get more interested in the hardware.

I work in a lab setting, and utilize a lot of analog signals (0 - 20 mA, 4 - 20 mA, and 0 - 5 VDC), and was wondering if I could use the hardware to log these signals into something like Excel, or some other recommendation that's a common application. I'm sure this is a common thought among people, and was hoping someone could point me in the direction of this being done or at least help on how to do this.

I'm sure there are projects out there that have done this, and if someone knows of someone who's done it, then I'd love to check it out.

I'm assuming you have the data acquired.

Being specific about Excel, if you have an older version,say Office 2003, you can send the data direct to Excel by using the macro PLX-DAQ. This effectively turns Excel into a terminal and it allows you to have live graphs. The time stamping can be done in Excel using the PC clock.

Any terminal programme, e.g. RealTerm, can make a text file of the data which can then be transferred to Excel. Timestamping can be done in RealTerm.

Thanks for the response, Nick_Pyner.

First, since I am new, I was looking at some hardware recommendations. What would be the best and easiest to implement on first? I guess I'd want to have something that has the most analog inputs for data, and also something that can be expanded.

Likewise, the data is acquired; it would be something constant since the DC signal would be continuous, and I'd use a clock to capture the signal whenever needed. It doesn't have to be an Excel file, I guess. It could be a .csv file, and then I can import into Excel perhaps.

What is "a lot"? 5? 500?

The basic 0-20mA and 0-5V signals are very easy to put into an Arduino's analog inputs. The 0-20mA current loop sensors will need a resistor to turn current into voltage. You should be careful with the inputs as anything over 5v will burn out the Arduino. If there's any chance that a sensor cable might accidentally brush against any other terminal at a higher voltage, then you should add a protection network on your Arduino board. A 1k resistor and a 5v zener diode will take care of most accidents.

For timestamping, it's possible to do this externally but often the best solution is a real-time-clock (RTC) module on the Arduino.

For large numbers of inputs, some kind of analog multiplexer or external A-D converter can be controlled by the Arduino. Some Arduino variants have more analog inputs than the others, so they may work for you.

I guess. It could be a .csv file, and then I can import into Excel perhaps.

Correct. I only raise PLX because it enables live reading in Excel, and also enables timestamping therein.

Any terminal programme can produce the same timestamped .csv files for subsequent use in Excel. You can also record .csv locally on SD card using timestamp from onboard RTC, thereby enabling Arduino to be independent of the PC, and the files can be transferred to PC at leisure.