RPi with an Oscilloscope and Java Embedded: Ready for Benchmarking
By hinkmond on Mar 04, 2013
Houston, we have an oscilloscope!
Yes, through hard work and determination, well... actually through the luck of the donation of an old leftover logic analyzer with an oscilloscope module from the former SavaJe acquisition via Sun Microsystems, Inc., which is now here at Oracle, we now have a scope here in the office connected to our Raspberry Pi running Java Embedded technology! Woo-hoo!
I want to thank Gary C. and Vlad D. in their help tracking down this awesome (er, uh... a bit old) piece of electronic equipment. In a back storage closet somewhere in the darkest reaches of our Burlington, MA office, this logic analyzer with oscilloscope module from SavaJe days, sat collecting dust. But, luckily Gary remembered it was sitting there unused, when I asked if he knew if we had a scope in our group for some needed RPi/Java Embedded work. And, then Vlad and Barb helped ship it out here to California and the rest is history.
After dusting it off, plugging it in, and firing it up, it works!
What you see in the top photo is a computer screen grab of the oscilloscope output reading of the GPIO port signal from the Raspberry Pi with a Java Embedded app driving a Pulse Width Modulation (PWM) wave. And look, Ma, no native C programming involved!
We can go over this in detail in my future blog posts so that you can do this at home as well, as we benchmark how fast we can get Java Embedded to drive that GPIO pin signal (I'm hoping for > 5MHz, but what you see in the graph above is a signal driving a blinking LED, so don't get all hypercompetitive... yet). And, might as well compare it to C native, since everyone else does.
Let the games begin...