Pic "tele-presence vehicle" design and software

 

A PIC 16F877A was chosen since it is used in many projects on the Web and has many features and including RS232 I/O USART firmware.

The software was designed using the Oshonsoft Basic compiler and simulator (this is splendid software, very easy to learn, and only €25)
A very good value PIC project board came from http://palmelectronics.net/EVA-001.html only spoiled by the poor documentation (that in the advert is all you get!).
- but I have been pleased with the hardware quality and value.The schematics extracted from the advert are here

I have tested the palmelectronics board by modifying the Oshonsoft examples (the Oshonsoft and Palmelectronics boards use different ports for similar external circuits) - my notes are here

A Basic program similar to this early version causes the Pic to mimic the pulse train in th RC transmitter.It sends to the transmitter five 300usec +5V pulses.The four 0V gaps are varied 1 to 2 millisec, one for each channel. A remaining long gap makes the period up to 20msec.

The Oshonsoft PIC basic program responds to single ASCI characters from a click on a region of an image map sent according to the code in the tables below.
e.g. If the Sweex sends the character M (Decimal value 77 or Hex value 4D) to the PIC the pic changes the gap_1 and gap_2 pulse lengths so as to center the 2 axis webcam

gap_1 = Channel 1 - rotate webcam to left or right
gap_2 = Channel 2 - nod webcam up and down
gap_3 = Channel 3 - steering position
gap_4 = Channel 4 - power level - forward (+volts) or back (-volts)
^
94
%5E

webcam control

 

Y
89
%59

y
121
%79

{
123
%7B
C
67
%43
}
125
%7D
b
98
%62
B
66
%42

steering
p 112 %70
o 111 %6F
k 107 %6B
j
106 %6A
h 104 %68
g 103 %67
f
102 %66

slow
P
80
%50
O
79
%4F
K
75
%4B
J
74
4A
H
72
%48
G
71
%47
F
70
%46

fast


forward

reverse

power
(
40
%28
U
85
%55
)
41
%29
u
117
%75
<
60
%3C
L
76
%4C
l
108
%6C
M
77
%4D
r
114
%72
R
82
%52
>
62
%3E
d
100
64
[
91
%5B
D
68
%44
]
93
&5D
V
86
%56
character
decimal
hex

note - cannot use / or +