User manual

80 l Robotics experiment with PIC microcontroller
7.2 ER-4 Infrared Remote control
l Operational distance is 4 to 8 meters in any open space.
l The 4-channel switch operates in an on/off mode
l Uses low power; Automatically resumes power-save mode once data is sent
l Uses only 2.4 to 3V from two AA batteries - both regular and rechargeable.
l Transmits serial data using the RS-232 standard with 1200 bps baud rate and 8N1
data format (8 data bit, no parity, 1 stop bit)
7.2.1Format of data sent by ER-4 Remote control
To make it easier for the receiver to read the switch value from the remote control,
the ER-4 transmit serial data according to the RS-232 standard, with a baud rate of 1,200
bps and 8N1 format. Characters are transmitted according to what switch is pressed on
the remote. The switch positions are displayed in Figure 7-2
Press switch A, the large cap A , followed by small cap A (a) is sent.
Press switch B, the large cap B, followed by small cap B (b) is sent.
Press switch C, the large cap C, followed by small cap C (c) is sent
Press switch D, the large cap D, followed by small cap D (d) is sent.
The reason that we have to alternate large cap and small cap letters is so that the
receiver can differentiate if a user presses continuously or if the user represses. If a user
represses, the large cap character will be sent the first time. If the user represses the same
button again, the small cap character will be sent the second time If the user presses
continually, the last character will be sent repeatedly.
Figure 7-2 : Shows the photo, board layout and Schematic of ER-4 Easy
remote control
+3-5V
GND
1
8
V
,,
GP2
5
IC1
ER4-FW
GP5
2
R1
1k
LED1
IR-LED
GP1
6
GP0
7
SW1
SW2
SW3
"A"
"B"
"C"
GP4
3
SW3
"D"
Q1
BC338
)
*+
,
IR-LED
KA
2-5V
Easy remote4
(A) (B)
(C)