The IR function library was one of the
first libraries I added to the Dios. It has been primarily for
receiving Sony IR codes. I recently started a new project
where I needed an IR transmitter. After an hour or so of
experimenting I came up with a new function to transmit the IR codes.
Its really strait forward, transmit
the first 7 bits of the command code then the 5 bits for the device code.
Start it all with a 2500us start bit
then use a 600us interval for low and a 1200us interval for high for each
bit transmitted. There is a 600us high pause between each bit.
I use the Hardware PWM to generate a
40Khz carrier and just turn it on and off as needed.
Hookup
There are two ways to hookup an IR
Emitter. The first is to just connect it directly to the Dios.
Schematic 1
You must use IO port 13 because that
it the port that the hardware PWM uses. A 39 ohm resister will keep
the IR LED from overloading the port. This will get you up to an 8
foot range.
The second approach is to use small
NPN transistor such as the 2N2222 to allow us to send more current to the
IR LED.
Schematic 2
The circuit used in schematic 2 will
allow you to bounce the signal off all the walls. The mini ultra is
used in the schematics but any of the Dios chips or boards could be used.
Lets Have Some Fun
In the following example I used a
modified 32 pin module to create a gag circuit. Once turned on and
placed near a Sony TV it will lower the volume every time some tries to
increase it. It will raise the volume each time someone tries to
lower it. My wife threatened to divorce me if I ever used it again
so use at your own risk.
!!! This is for demonstration purposes
only !!!
Schematic 3
In schematic 3 we add
a Vishay IR module. It is powered by the IO port leads 1 and 2 set
to low and high. This will allow us to plug it directly into the IO
port holes.
The same is done with
the 2N2222 transistor. It is plugged into IO Ports 12, 13, 14.
12 and a 14 is left as input so the actual voltages placed on the pins
does not matter.
I have also connected
the optional voltage regulator to the Dios 32 Pin module. This way I
can power the whole thing with a 9v battery.
I placed the whole
thing in a small radio shack case. Part number 270-1802.
It makes the perfect
size for hiding in a inconspicuous place.
The Program
(download it here)
'Simple IR Gag
func main()
dim cmd
'Used to power IR Reciever Module
'Port 0 is IR Mod input
output 1,2
low 1 'Port 1 Gnd
high 2 'Port 2 +5v
IRinitsend()
loop:
'pause 10
cmd = IRread(0,10000)
if cmd = 0 then
goto loop
endif
print IRcmd," ",IRdevice
if IRcmd = 19 then
dovolup()
goto loop
endif
if IRcmd = 18 then
dovoldown()
goto loop
endif
endfunc
'Force the Channel back down
func dovolup()
dim x
pause 5000
for x = 1 to 40
IRsendcode(1,18)
pause 50
next
pause 1000
endfunc
'Force the Channel back up
func dovoldown()
dim x
pause 5000
for x = 1 to 40
IRsendcode(1,19)
pause 50
next
pause 1000
endfunc
include \lib\DiosIR.lib
The program uses the
functions added to the library. IRinitsend() and
IRsendcode(device,cmd).
You can use these
commands with any application. You can create your own remote or use
them to add some wireless communications between Dios projects.
Parts
list
Vishay IR Module
IR Emitter LED
2N2222 Transistor
Voltage Regulator
8" Battery clip
12 Pin Female Header
DiosPro 40 Pin Chip
Dios Workboard
Deluxe
Easy RS232 Driver
DiosPro 28 Pin Chip
Dios 32 Pin Carrier
(Carrier #1)
9 Pin Cable
Breadboard Regulator
