Arduino based micro-controller main projects list :

1. LCR meter : Link
2. C meter : Link
3. LR meter : Link
4. VI meter : Link
5. FM radio : Link
6. RF data link : Link
7. Alarm clock 1 : Link
8. Alarm clock 2 : Link
9. Alarm clock 3 : Link
10. Timer 1: Link
11. Timer 2: Link
12. Espressif Systems project list : Link