Quick Start Guide
This page is meant to serve as a quick reference for new owners of the Heart Spark Logging device, to get you quickly up to speed and collecting and analyzing your data.
- Heart Spark Logging
- FTDI board with mini-USB cable
- Processing installed on your computer
- HeartLogger program downloaded
If you’re on Windows, you’ll also need to install the FTDI drivers. Drivers are already included on Mac OS X and on most distributions of Linux, so no driver install is required on those platforms.
Launch Processing, and Open the Heart Logger application:
Then simply press the “play” arrow on the upper left hand side of the processing app. This will compile and launch the HeartLogging app:
Now hook up the FTDI cable to the Heart Spark (the board really only mounts one way, but see picture if you are unclear), and the cable to your computer:
Not that it will work if you leave the battery in, but this is not recommended procedure. It might have negative effects on the battery. Now it’s simply a matter of clicking the buttons in the Heart Logger program in order, from left to right
- Open Serial Port: the FTDI board emulates a serial port over USB. You’ll be opening this virtual serial port in order to communicate with the Heart Spark. If it doesn’t work the first time, try unplugging the USB cable from your computer and replugging it in. Then wait a few seconds and click the Open Serial Port button again.
- At this point, if you are expecting there to be data, you might wish to rename the default file (in the blue outlined box) to something more meaningful, e.g. “HeartData_YogaAndWork_2011Feb13.csv”, or something that will mean something to you if you ever look back at the data again.
- Grab & Log Data: This button will start the data acquisition process. If this is your first time using the device, there won’t be any data, and it will tell you so. But you must still click the button – this step also sets the data and time on the Heart Spark, so that it will be correct for future logging. If the program tells you that there isn’t any data, but you think there should be, use the “Grab All Data” button, which will pull ALL of the data from the EEPROM, regardless of it’s contents. It’ll probably be a mess to figure out later, but it’s better than data loss! While the data is being pulled, it will flash over the GUI. You’ll be able to get a feel for how clean your data is, but it’s hard to get much of a feel for whether the data is interesting when you see it so fast. The data will be stored in the filename you specified earlier. The Heart Spark itself will be RESET, so that data will begin to be written at the start of the memory space again, slowly overwriting the data you just captured to file.
- Quit: this will close the virtual comm port and quit the program.
Once you have the .csv file with your data, you can remove the FTDI cable from the Heart Spark, and return it to operation. Note that if you wish to preserve the date and time you just set on the device, you must insert a battery within about a minute of removing the USB power.
Now that you have the data, you can analyze it in any way that you like. Using MS Excel, or any other plotting program, be sure to use the “scatter plot” (also called “xy plot” or “dot plot”). Plot the time (in minutes) versus the Heart Rate (in BPM). It’s important to use a scatter plot because otherwise periods with higher heart rate will be stretched and look like it took more time than it actually did.
I have written a small Heart Plot Asymptote program to create pretty PDF files straight from the .csv files. You just have to specify a number of arguments from the command line to get it to go. If you’re comfortable with the command line it’s a super fast way to generate plots, way way faster than manipulating a GUI of any sort, especially once the number of data points starts climbing upwards. If you’re interested in using this and can’t figure how from from the code just shoot me a quick email eric at sensebridge.net, and I’ll write something up.