Oct. 23, 2012
Mongo for the Mission Critical Enterprise
Here's a talk I gave in October 2012 for MongoBoston.
The presentation describes the architecture and strategy we used at EnerNOC to implement a highly scalable backend platform for our energy management SaaS. Our platform handles millions of data points per day as part of a grid-critical infrastructure that requires zero downtime. The backend is ultimately a combination of several persistence solutions that all need to scale ...
Sept. 7, 2012
Changing Calendar Colors on Android
This one is almost silly, but since I haven't posted in a while...
Android doesn't let you change the account color for exchange calendars. Instead it picks a color at random when the account is first created. Awesome. Well, it's not *too* hard to change without a dedicated app. Let's get started...
First I need to open the android shell (adb shell) and find ...
June 26, 2012
Smoothing Sensor Data, Part 2
After a query from an older blog entry, I figured I should properly follow-up since there were a couple questions about how to use the low-pass filter I described to smooth sensor data from Android.
So the question was "shouldn't the algorithm be output[i] = output[i-1] + ALPHA * (input[i] - output[i]);" Well, the answer is no, here's why:
So the wikipedia entry I referenced uses ...
June 3, 2012
Using Smack XMPP with JAXB
So it I've looked a few times in the past, trying to find a decent way to use JAXB with the Smack XMPP library for Java. More to the point, I wanted to write a Smack provider to parse a custom IQ message, but use JAXB to unmarshal the IQ body. Should be doable.
Nobody on the Smack forums had seemed to figure out a way to ...
June 1, 2012
The Raspberry Pi has landed
Like a kid with a new toy, my Raspberry Pi was delivered yesterday.
And once I got it home, this was the only HDMI monitor I had...
Can I say, thank goodness the Raspbian distro has sshd enabled by default! I spent probably 20 minutes searching around the house for a keyboard. I don't have a USB keyboard in my house because I haven't used a ...
