These
page are published for my own use and are created so that I have a record
of the design for use in a few months time when I have forgotten how it all
works!
Storing my programs on my web host proves to be more secure than on my hard
disk!
If you find the content useful or if you have any contribution please email
me or leave a note on the forum
on this site. Work in progress!! use at your own risk.
Project - "Tele-presence" Vehicle
Objectives
1) Build a free roaming
electric vehicle that carries a webcam.
2) Control the vehicle and the webcam from a web page displayed on a remote
computer.
3) Use these notes to "meet" others with similar interests who find
the content on Google
Reasons
1) Enable members of my
family who live on the the other side of the planet to visit my garden in England
by "tele-presence".
2) Learn embedded Linux and microprocessor hardware and software application.
Method
Host the webpage in a Sweex
router in the house running Linux.
Have commands from the webpage control internal Linux scripts and c coded programs
that send data via an RS232 serial port to a PIC 16F877A microprocessor.
Cause the PIC to generate a pulse train that mimics that created within a 4
channel 27MHz AM radio control transmitter. Inject this into the transmitter
in place of that created by the internal potentiometers and encoder chip.
Build a 4 channel RC receiver into the electric vehicle. Use 2 channels for
a 2 axis webcam control and use the other 2 channels for vehicle steering and
power control.
Employ a colour TV camera on the vehicle feeding a 2.4 GHz radio link to a receiver
in the house that feeds the picture to the web page.
Note
A wireless internet connection (WIFI) was first tested but the power consumption
was too great. This might be reconsidered later under the control of some micropower
circuit that switches it on as needed. This might be an Atmel Butterfly microprocessor
board and low power receiver.
I also hope to test a wireless RS232 link.
Progress
so far
Sweex
software - later
PIC design and software - tests
on pic here
Radio control Link - moving
to wireless RS232
Webcam
Vehicle control hardware
- H-Bridge tested - servo pulse to PWM (PIC program) tested
Compass - an i2c compass linked to the Rover PIC
Ultrasonic Ranger - detect walls that get in the way
GPS receiver - probably not accurate enough but worth a test since I have a second hand GPS module