DS213 customized firmware with Roll Mode support.

[spadger]

Based on the official app firmware v1.27, and  fixed some bugs. This is the test video:
https://youtu.be/iGE-QNMqRk0
Tips: What is Roll Mode?
https://www.sweetwater.com/insync/roll-mode/
On an oscilloscope, roll mode is a method of displaying acquired waveform data without waiting for the complete waveform record. For example, if a sweep was 10 divisions long with a rate of one second per division, and roll mode wasn’t available, it would take 10 seconds to fill the waveform record. But using roll mode, the oscilloscope will immediately begin displaying results rather than waiting the full 10 seconds.

[bobdavejimerson_iv]

This is great! Thank you.

[spadger]

The project is now open source on github.
https://github.com/xjtuecho/DS213_ECHO.git