Wednesday, October 9, 2019

New probe has 12h battery life as previous

Just confirmed the new probe has a 12 hour battery life, comparable to our previous design. This is not surprising, given that it's just a recasting of the same hardware, but it's still good to know. Here is the probe sitting on my desk at work today. The LED blinks on or off per data cycle, so it is blinking at 10 Hz and the data is going out at 20 Hz:


Friday, October 4, 2019

New probe design

It's been a while since we posted, and it's not for lack of activity.

We have switched to using Honeywell pressure sensors, since they are (as best we can tell) more reliable. And since they are not as easily available in different types, we decided to use a Bosch BMP388 barometer instead of a high-zoot ported pressure sensor. This meant we were up for a big board rev.

In the meantime, we re-evaluated and decided we could get by with a less custom sensor board, using a few "breakout board" components to simplify our buildup for prototyping.

The result is our "maker style" probe, which we just got together:






Notice the following:

* Compute module is a SparkFun Pro Micro 3.3V.

* Power is provided by a SparkFun Battery Babysitter.

* Barometric sensor is an Adafruit BMP388 breakout board with a 3D printed "cap" to provide a port for redirecting the static probe pressure to the sensor.

* The static probe is now attached via a 3D printed pylon to avoid having to bend tubing, and it is made of a piece of regular hobby store brass tubing.

* Various changes have been made to the mechanical parts to make them easier to assemble.

We will be trying this probe out in flight and also, as we build more copies, showing more details of how it's put together. We're still trying to iron out some of the bugs.

Stay tuned!!!