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7. IR Transmitter RC-5 Coded R763569
7.4 Technical Info
Pin Assignment Micro Contoller
10
RB 0
Row 7
11
RB 1
Row 6
12
RB 2
Row 5
13
RB 3
Row 4
Scan Outputs
14
RB 4
Row 3
15
Row 2
RB 5
16
RB 6
Row 1
17
RB 7
Row 0
18
Col 7
RC 0
19
Col 6
RC 1
20
Col 5
RC 2
21
Col 4
RC 3
22
Col 3
RC 4
23
Col 2
RC 5
Col 1
RC 6
24
25
Col 0
RC 7
Image 7-8
Pin assignment micro controller
RC5 Sequences
R C 5
q
s e
u e n c e s
Command String
24,9 ms
Image 7-9
RC5 sequences
40
3
+5V
VDD
1
Keyboard
TOCK1
28
(active=L)
MCLR/Vpp
27
Osc.1 /CLK In
26
Osc.1 /CLK Out
PIC
16C55
6
RC5 modulated Out
RAO
Keyboard
7
RC5 unmodulated Out
RA1
Sense Inputs
(active=L)
8
RA2
Backlight Out/Jack sense In
9
Laser driver Out
RA3
4
GND
VSS
Command String is repeated every 114 ms
114 ms
Command String
1
1
0
0
0
1
0
1
2 x S tart
T og gle
5 x A ddress
B it
B it
B its
The Burs
t F
q
y i
3 6 k H
r e
u e n c
s
27.8u s
Pin functions:
VDD
: Power Supply
VSS
: Ground connection
Oscillator (osc1, Osc2
with 2 load capacitors of 82pF.
MCLR Reset Input
- Power On: all memory locations are initialised.
- Awake from sleep: option jumpers are scanned and
memorised, keyboard matrix is scanned, key entries are
processed, and the device goes back to sleep.
RA0/RA1:
RC5 modulated/unmodulated driver outputs:
active=H
Pulse sequence: RC5; with/without 36 kHz Carrier Frequency
respectively.
RA2
: Backlight Sense Input/Driver Output: active=high
Turns on for 5sec when a key is hit. This period is retriggered
when another key is hit. During this period, the PIC doesn't
enter the sleep mode.
If this pin is tied high (through a resistor) before it is driven high
internally, the program assumes that the Remote Control is
connected to a projector by means of the jack connector. In this
case, the modulated RC5 driver output is disabled internally.
RA3
: Laser Driver Output active=high
RB0..RB7
: Keyboard Scan Outputs active=low
RC0..RC7
: Keyboard Sense Inputs (External pull up resistors)
active=low
The RC-5 Code
In the RC-5 standard a bi-phase coding (Coding: a
0
1
0
0
0
1
rising edge within a time window is equivalent to a "1",
a falling edge represents a "0") is applied. The carrier
frequency is fixed at 36 kHz.
The transmission of a word begins with two start bits,
followed by a toggle bit. The toggle bit changes its
6 x C om m and
B its
value at each key operation. With this change an
interruption of the transmission link can be
distinguished from a multiple key pressing. The 5
address bits address the device to be controlled, the
i t h
3 3 % d
t y
y
l
a
c
c
e
z
w
u
command bits contain the information to be transmitted.
,
Each bit in a data word consists of a burst of 32 pulses
with a repetition rate of 36 kHz. The equivalent times
are shown on the puls diagram.
): Use of a 864 kHz Ceramic resonator
: to be activated in 2 cases:
Command String
R5976820 SLM R12+ PERFORMER 08/03/2005
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