This new update is a little bit bigger than the last one. One major new feature is the option to record spectra 100% locally on the device and save the data to the onboard flash to be retrieved at a later point. You can start a recording via the serial interface and then keep track of the status or stop it manually before it finishes. The data that has been gathered can be again printed to the serial interface at any point after that. For this I have also added a couple new commands relating to the filesystem on the Pico's 2MB flash.

Because of these changes, your current settings and also the runtime stats of your device will be reset once you update! So be sure to note your settings beforehand and restore after the update if you changed anything.

There are also some smaller changes like a change in default settings (see below) and better formatting for the general info and fs info screens over the serial interface.

Full list of changes:

• Flash space (total 2MB) on the Pico is now divided 50:50 between the onboard file system and the program space (1MB for the filesystem). This change will result in a reformat of existing devices.
• Changed default settings for "subtract_baseline" and "cps_correction":
  
  • subtract_baseline = true
  • cps_correction = false

• Improved formatting of "read info" and "read fs" info screens. Also removed some irrelevant data from the "read fs" screen.
• Standalone recordings: Start and stop spectrum recordings via the serial interface, the rest will be handled by the device, you don't need an active connection in between and you can collect the data anytime after it finishes. The data will be saved to flash in a compatible JSON (NPESv2) format for viewing in other software. There is also a tiny indicator on the OLED for when the device is currently recording. The device will stop recording after the set time has run out and will autosave regularly (every 15 minutes) just in case of a power failure. New serial commands, pretty self-explanatory:
  • record start <time in minutes> <filename>
  • record stop
  • record status
• New filesystem commands to view the contents of the data directory and of files that were previously recorded (NPESv2 JSON). There is also an additional command to remove files once you don't need the data anymore. The 1MB of flash on the Pico FS can hold a lot of spectrum files (get used and free sizes using "read fs" command). Commands:
  
  • read dir
  • read file <filename>
  • remove file <filename>

I think these are really cool changes and finally start to show the power of this device. Neither do you need a sound card or any additional hardware to generate spectra, you don't even need a computer all the time anymore with the stock firmware. Set and forget. Set up your serial recording, and then come back hours later to "download" the data from the device. Just copy paste the contents into a file on your system and open it in Gamma MCA or a compatible program to view in all its glory. No additional computing needed. Doesn't matter what you do with your computer. Just be sure to keep the device powered ;)

Enjoy!