Infrared

IR Transmitter and Receiver

What is infrared (IR)?
- Invisible to the naked eye
- Used in wireless communications
- Line-of-sight: transmitter must be pointed at the receiver
- Short range: 10-20 meters
Examples of consumer IR devices
- TV remote control
- Video game controller
IR on the CPX
- CPX device has a transmitter and receiver
- Setup 1: two CPX devices
  - One CPX sends a value and the other receives it
- Setup 2: one CPX device and one mini-remote control
  - Remote control sends a value and the CPX receives
  - This setup will be used for the final project

The simulator presents two CPX devices: one will act as the remote (sender) and the other will receive

Receiver uses logic block to take different actions based on the value transmitted

IR blocks available under Network

By default, the received value is assigned to variable num

The function “on infrared received” corresponds to the receiver.
The function “infrared send number” corresponds to the transmitter
We use the inputs to transmit different infrared numbers.
We need to build the logic inside the “on infrared received” function to perform different actions based on what number it receives

CPX receiver logic block can become quite large
- Tip: use functions to split up the code into smaller, more manageable chunks
If both CPX devices are programmed the same, then either can act as the sender or receiver
With 2 buttons and 7 touch sensors, the CPX device can be easily programmed to send 9 different values