// output mode = 00 (disconnected)
TCCR1A &= ~(3<<COM1A0);
TCCR1A &= ~(3<<COM1B0);
- TCCR1B = (TCCR1B & ~(0x07<<CS10)) | (2<<CS10); // 2MHz timer
+
+ // Set the timer pre-scaler
+ // Generally we use a divider of 8, resulting in a 2MHz timer
+ // frequency on a 16MHz MCU. If you are going to change this, be
+ // sure to regenerate speed_lookuptable.h with
+ // create_speed_lookuptable.py
+ TCCR1B = (TCCR1B & ~(0x07<<CS10)) | (2<<CS10);
OCR1A = 0x4000;
TCNT1 = 0;