February 23, 2025

Synced up with Dad to talk about the Aerialometer and remember how it works. A bunch of notes:

• The aerialometer has a microprossor and it’s running some code that can be deployed via an .ino file. Need to plug an FTDI connector to the device to be able to deploy new code. The FTDI device can also be used for debugging. I ordered this one on Amazon to get set up here.
• The compute on the device is running the program and also has a flash storage (it’s the same as any other arduino file)
• The code itself relies that the gyrometer and the accelerometer can sample on a continuous rate. Data is sampled and written to the flash memory. The device accepts an interrupt from the processor which acts in a blocking manner and writes the data from the flash to the SD card. There’s a fixed sampling rate for the hardware so there are no gaps in data.
• To operate the device, it’s good to refresh memory on what the various flashing modes mean, as they indicate a number of states. Roughly, to operate:
  • Turn on the switch on the back of the device. This will start up the device and get it ready to go.
  • Tap the device (hard!) to begin sampling data.
  • Tap again to stop device collection. This should kick off the data transfer to the SD card.
  • When turning off, the data will continue to write to the SD card (if not already complete)
  • Once data collection is done, the device will finally switch off and lights will stop flashing.
• There is some funkiness with the SD card currently. My mac won’t recognize it. Current theories are that the device is corrupting the cards, or that the card is too big, or not formatted correctly. Next up, need to debug. Also ordered some 128 MB (MB! not GB!!!!) SD cards so they can be formatted with FAT, not FAT32. Cards can be formatted using the Disk Utility app on Mac (don’t need to install a separate program).

I also got to spend some more time on the sunfounder kit!

• Connect an LED and flash it on and off. Make sure to connect resistor to the short pin end of the LED so that the LED doesn’t smoke out.
• Reminder that any of the pins labeled “GP” on the pinout can be used as GPIO, so select one that is convenient. The device has many grounds, too.
• When referring to the pin in code, need to use the GP number, not the Pin number (Pin 20 is GP Pin 15, so need to use 15 in the code).