Imagine it, it's 3:15 on a weekday afternoon and you've just realised you've forgotten to set the video to tape 'Pet Rescue'. Usually you would be condemned to an afternoon of misery and disappointment, knowing you had no heartwarming cute animal stories to come home to. But not any more. Below I describe a simple interface between a T28 mobile phone (ME) and Matsui VX770 VCR to allow remote recording of programmes.
source : http://www.frisnit.com/sms/index.html
Block Diagram
The heart of the interface, the only active component, is a PIC16x84 microcontroller.
It has 1024 bytes of program/data memory, 36 bytes of static RAM and 64 bytes of non-volatile RAM. In this application it runs at 6 MHz, giving an instruction cycle of 0.67us (1.5 MIPS), plenty to handle the low data rates of the two interfaces. Read all about the awsome power of the 16x84 here.
Two interfaces are required, one to the ME to send and receive SMS messages and one to the VCR to control channel selection and recording. These are described below.
VCR interface - infrared protocol
ME interface - AT command set
Once these interfaces are implemented, some simple logic holds it all together to control channel selection and recording functions. The PIC ASM code can be downloaded here.
Click here to see some more pictures of the setup
Results:
