AXEtimeter I - model rocket datalogger - part 5


Senior Member
Here's a video of the launch and catch by my daughter (she put it on the ground so it would detect the landing and watched the shutdown sequence :D )

Note the requisite flight gear:
Black sack for launching pad, engines, igniters, etc - CHECK
Disney Princesses lunch bag in case we get the munchies - CHECK
Fingers to plug ears for super-loud launch - CHECK
All systems go!

And a short video demo'ing the blinking out of the last flight altitude and EEPROM storage status is at:

:( can only embed one video per post

I'll update blog post 'part 3' with the updated code files in a few days. I have added some optimizations to the logging routine and added the capability to blink out the actual supercap voltage. BTW, after 3 flights and data download, the supercap was at 1.7V.

UPDATED: I added the latest code (v1.0.8) to blog post #3 and below. The supercap voltage will blink out on the LEDs. 2.13V would be 2 blinks on the 100s, 1 blink on the 10s, and 3 blinks on the ones. :)

View attachment 17013


New Member
Have two Estes rockets both fitted with commercially made altimeters. After reading your article I am contemplating building this project but using standard chips instead of surface mount. The problem Im having is the M41T62LC6F real time clock which only appears to be available as surface mount, problem is connecting to pads on underside of chip. Are any of the PCB's available to purchase as the surface mount version is the most space saving route.


Senior Member
I don't have any more of those PCBs, I've built them all out for my family's rocket collection. There is a bigger leaded surface mount option from ST, model M41T81S, that has the integrated crystal and 1/100 seconds capability in an easy to solder SOIC 18pin package. If you don't care about 1/100 second resolution, then Maxim's DS3232M is a great MEMS-based RTC in a small SOIC 8pin package.