Hey everyone, I’ve been working very hard on getting the data and tracking payload up and running, and as we approach launch day I wanted show y’all what everything looks like.

System Overview

As a reminder, here is a system level overview of the payload:

And here is the payload all packed together in it’s box:

And finally the outside of the box:

The arduino will be collecting data every 0.5s and logging it to the SD card in CSV format, while APRS is transmitted every 60s. Over the past couple of days, I have discovered there is some interference between the thermocouple and the APRS transmitter, but since that data logger continues to run correctly I plan to interpolate the temperature values for the samples that are incorrect.

Another side project I have been doing for fun is building my own portable iGate using some equipment I had laying around. What an iGate does is take APRS packets and forward them to the internet so others with internet access can track objects. While we should be able to hit the regular APRS network when the balloon is higher up, it could be difficult when it is lower. So using a raspberry pi, a software defined radio dongle, and my phone as a modem, I built my own simple iGate to run in my car.

Here is a photograph of the output from the raspberry pi:

And a screenshot of the APRS data on the internet map:

Data output:

I’ve also been doing some demo experiments to produce sample data for processing. Here is the output of a drive I went on:

 

 

 

 

 

 

 

 

While there are some noise on the data (the spikes) I plan to write a script to remove the noise in post-processing.

For those that are really interested in getting in the nitty gritty, check out our GitHub repository. I plan to post the raw data there after the launch.