This post was originally published on October 25, 2017 at https://sparklechicken.net/channel/jakessbc

Last week, the GPS sensor and SD card breakout finally arrived.  They both work beautifully…as long as you don’t use the SD card reader with anything else.  The combination of SD.h and SPI.h uses 50% of the Arduino Uno’s space for global variables right off the bat!  After doing some searching, I found the Adafruit Metro M0 Express, a board that is form factor and pinout compatible with the Uno, but built with a Cortex M0+ microcontroller that has 8 times the flash and 16 times the RAM.  I’ll be cooking with gas when it shows up tomorrow.

The GPS works well, even without an antenna, but I still have yet to do quality tests with it.  The other thing that I need to test is the accuracy of the barometric altimeter vs. the GPS altitude reading.  I’ve heard that the GPS altitude can be a bit iffy, depending on the quality of your fix, but if it is more accurate than the barometer then that is one less sensor I have to throw into it.