ماژول فرستنده FM رادیویی TO27

KEYS:

K1: Short press, plus frequency 0.1MHz, long press, frequency plus 1MHz

K2: Short press, reduce the frequency of 0.1MHz, long press, reduce the frequency of 1MHz 

K3: Short press, volume up(total volume 4 step), long press, display 

K4: Short press, volume down(total volume 4 step), long press, restore factory settings, the frequency of 99 MHz, Volume step 3

Display frequency:

This board display frequency with 4 blue LEDs. If current  frequency is 87.5MHz, long press K3, the second LED flash 8 times, the third LED flash 7 times, and the forth LED flash 5 times.