The software defines 2 Run modes, giving 2 distinct behaviours to your transmitter.
You select the desired run mode with the MODE switch.
Transmission mode
Transmission mode is selected when the MODE switch is opened.
The morse code corresponding to the active Model number (see Selecting a model) is played 3 times with the piezzo buzzer and flashed continuously on the LED.
The transmitter sends PPM signals corresponding to the positions of the controls. If you move the sticks, the servos connected to the receiver will respond. This is the normal way to use your transmitter.
Command mode
Command mode is selected when the MODE switch is closed.
The Command mode code is played 3 times with the piezzo buzzer and flashed continuously on the LED.
Use this mode to verify or to change the settings of your transmitter. The settings are stored in the Arduino's EEPROM and you must connect the Arduino to a computer to change them. While in Command mode, the PPM signal sent to the receiver is not as accurate as in Transmission mode, so it is not advisable to fly your planes while in Command mode.