Day 18: Universal remote control

Fri, 18 Dec 2015 00:01:00 +0100

Yesterday, you built a receiver for infra-red remote controls. Today, you are building the remote control itself. More precisely, you will build a universal remote control that you can operate by computer or Smartphone and with which you can operate your TV or other devices whenever you misplace the original remote control.

The IR-diode at Pin D3

For this project, you need the component behind today’s door: the IR diode. It looks like a simple LED, but it sends light in the invisible infra-red range. The IR-signals are visible to a digital camera, however. The structure of today’s experiment is shown in the figure. Don’t be surprised that the IR-LED is not given a dropping resistor. The effective dropping resistor is the On-resistor of the port, at approx. 30 Ohm. Because of this, the current through the diode is quite high, but the impulses sent are so short that the diode will not take damage.

IR-Diode on Internet of Things with the NanoESP

Day 18: Universal remote control