Infrared Remote Control Decoder


This is a kit consisting of a programmed Microchip PIC (14-pin DIP), a three terminal 38 kHz infrared receiver, five LEDs and lengths of 22 awg solid wire suitable for assembly on a solderless breadboard.

It is for use with a Sony remote control as would normally be used with a television. When keys 1, 2, 3, 4 and 5 on the remote are momentarily depressed, the corresponding outputs on the PIC arelatched high. When keys 6, 7, 8, 9 and 0 are momentarily depressed, the corresponding outputs 1, 2, 3, 4 or 5 are brought low. Thus, depression of key 2 causes output 2 to operate. Key 7 causes it to release.

This may be used to operate and release relays or to interface with a Basic Stamp, Arduino or similar microcontroller to operate motors, change speeds and directions, etc. Note that the outputs of this PIC device are capable of sourcing or sinking nominally 15 mA (5 VDC). For directly interfaing with relays, lamps, motors and the like, FETs or NPN transistors are suggested.

When any key is depressed, a Signal Present (SP) LED is momentarily turned on (250 ms) and then off. This is any key, including the numeric keys, PWR, up and down volume, up and down channel, etc. But, note that only the numeric keys control the PIC outputs.

In addition, when any key is depressed, the corresponding code is sent in two digit hex format at 9600 baud. This might be read by a PC or microprocessor. This might be used in a monitor function or specific codes may initiate actions controlled by the PC or microprocessor. Again, note that this occurs for any key, and not just for the numeric keys.

The polarity of this serial output is determined with a strap on a PIC input. When the strap is at GRD, the serial idle state is high. This mode would be used with microprocessors or with a PC using a USB adaptor. When the strap is open, the idle state is low. This would be used in directly interfacing with a PC Com Port. Note that this strap is only read when the PIC is powerd up or reset.

This kit requires a source of +5 VDC capable of sourcing 50 mA if all LEDs are turned on. With all LEDs turned off, the current is less than 1 mA.

Any universal remote control should include the Sony protocol. I also have a few ChunGhop universals which use code 005.


Schematic.