Seven Eight-Button IR Remote Control (PIC12F1840)

UPDATE: 12.1113: It's actually an 8-Button IR Remote. I didn't populate the eighth button because it wasn't needed it for the amplifier controller design. I'll update the schematic / pictures for the eighth button.

UPDATE: 12.1114: Added pictures of modified remote (now eight button).

UPDATE: 12.1114: Added second sheet of schematics, updated to V1.01, removed 7-button 4015 pics.
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I've been working on this 8-Button IR Remote Control for a while, but I never got around to documenting it. So - I've drawn up one sheet of the schematics and decided to post it. When I finish the second sheet (with all of the buttons and the HEF4015 interface), I will also post that.

This came about because I was working on decoding IR commands using a PIC. I have a PIC-controlled amplifier interface I am working on and I wanted to incorporate IR remote commands for changing the volume, selecting the input, etc. etc. That led to my wanting to creating a specialized IR remote control for that amplifier project, which led to this.

It works rather well, except that I only have a range of 4-5 feet. I've tried all sorts of configurations of the IR LED circuit and 4-5 feet is the max range I have been able to achieve. Does anyone out there have any ideas on what I can do to improve the range?

The really cute thing is that there is an bit-banged I2C interface that can drive a 2x16 LCD display module. That was helpful when I was trying to debug some issues, but mostly just a neat hack that really isn't that useful. And - too expensive for a cheap remote.

The component side of the 8-Button IR Remote Control
that has the HEF4015 interface to the buttons.

 

The back (ugly) side of the 8-Button IR Remote Control
that has an HEF4015 interface to the buttons.

The componet side of a 7-Button IR Remote Control

that has a resistor ladder interface to the buttons.
Using the resistor ladder interface was something
I had seen used in TV sets, and was neat that I could have
multiple buttons using only one pin on the PIC. BUT -
completely unreliable. That's why I went with the HEF4015.

The back (ugly) side of the 7-Button IR Remote Control

that has a resistor ladder interface to the buttons.

The 8-Button IR Remote Control with the HEF4015 interface
to the buttons, connected to a battery pack and an 2x16 LCD
display with an I2C interface. Yes, even without the LCD display,
the whole package needs to be much, much smaller.