Data Visualization

Other Hardware Sensors
1

Just ordered the Muscle Sensor v3 from Advancer Technologies. It believe it comes with the Arduino source but I'm not sure how to visualize the data?

It's an EMG sensor so it's putting out a waveform. What my tool of choice to view the sine wave?

Product: http://www.advancertechnologies.com/p/muscle-sensor-v3.html?m=1

Side note: I want to connect this sensor + circuit to my Uno that will have a Bluetooth shield on-board. I found a neat Bluetooth tool for Android and was also hoping/wondering if that's a tool I can use to visualize the data as well. Thanks for tips in advance.

2

Bump

3

The sensor should be connected to an analog port; there is only one wire (plus ground, of course) that goes from the sensor to arduino. The sample code from the Advancer simply reads the voltage on that wire (assumes the wire is connected to A6), and sends the value to the Arduino's serial port. It is totally up to you what to do with the data. If you open the serial monitor on the PC attached to the Arduino, you'll see numbers, and a lot of them - one every 10 milliseconds. Of course, if you connect a BlueTooth module to Arduino, you can get those numbers over to a device that pairs up to the Arduino's BT. The thing is, those are still just numbers, one every 10 ms. Visualization is another animal alltogether. If you are on a PC, LabView or Matlab for example support data visualization in just a few steps. On an Android device, you may try MIT's AppInventor (online Android app development environment, graphical interface, requires no programming knowledge, simulates the phone too, very nice. In just a few minutes you can create an app that plays a tone corresponding to the number received over the BT :slight_smile: )

4

There seems to be Processing sample code on the product page(nearby the arduino sample code link).
I think that is the easiest way to visualize the sensor data with arduino.
If you have no idea what Processing is, see http://www.processing.org/ .

Also note the following product description:

RAW EMG vs Rectified & Smoothed EMG
Our Muscle Sensors are designed to be used directly
with a microcontroller. Therefore, our sensors do
not output a RAW EMG signal but rather an
amplified, rectified, and smoothed signal that will
work well with a microcontroller’s analog?to?digital
converter (ADC). This difference can be illustrated by
using a simple sine wave as an example.

5

Thanks

6

Here is the project that does exactly what you are looking for:

http://www.dustynrobots.com/news/seeing-sensors-how-to-visualize-and-save-arduino-sensed-data/

It just works. Two things to watch for:

  • Make sure that Serial.begin (line 5) in the Arduino code uses the data rate that matches the Bluetooth module setting.
  • The Processing code (line 11) portName = Serial.list()[x] needs to index to the port that has the Bluetooth dongle attached to; on my computer, on initializing, the processing code reports [0] com1, [1] com2, [2] com5; to plot the data that comes through bluetooth (com5 on my computer), I'll have in line 11: portName = Serial.list()[2]