- PICs & Kits
IR Link Hardware
Notes on the
- The circuit
has been changed. The old circuit still available.
- The new
circuit has a better pin allocation which makes
it easiyer to implement and build. It has also
support for 2 IR LEDs, each one controlled by a
pin (thus 25mA is source in each IR LED).
- The 4MHz
crystal with the two 22pF to 22pF capacitors is
equivalent to a 4MHz resonator.
- The circuit
can be powered from a 9V battery, since there is
a +5V voltage regulator. It can be also powered directely
from a 4.5V flat battery (without the use of
regulator). A 4.5V battery has a long life and is
cheap, but a 9V one is more portable.
- A PIC16C84
or a PIC16F84 can be used. However a PIC16F84 is
better and cheaper. When programming a PIC16F84,
make sure you set the fuses to: XT, WTD_ON and
PWR_ON. You can also have Pre-Programmed PICs from me.
forget to download the LITE code for the PIC from
the Software downloads section.
- In the LITE
version there is only one switch used. The other
switch is only useful in the STANDART version.
330 Ohm, 470 Ohm, 2 x 120 Ohm, 2 x 18k Ohm, 2 x
4.7 uF (Tantalium electrolyte prefered), 33uF
Tantalium (equivalent to 100 uF if normal
electrolyte capacitor), 0.1 uF (Tantalum
crystal oscillator with 2 x 22pF capacitors, or a
Diodes: 2 x
1N4148, any RED LED, 2 x IR LED (see below).
Regulator: LM2931. A 78L05 regulator can be used,
but you should be careful choosing other
SFH506-30 or SFH506-33 from Infenion/Siemens
IR reciever module: The essential part is the SFH506-30/33
from Siemens. The SFH506-30 operates at 30khz and the SFH506-33
at 33kHz. The PIC program changes according to which SFH506
This module can be purchased in many places. Check the
Pre-Programmed PICs page.
IR LED: Any IR LED that has a wavelength
of 950 nm can be used instead of the SFH415 from Siemens.
In the Datasheet of the SFH506-30 they say that with the
SFH415 a range up to 34 m can be obtained.
the range: To extend the range,
multiple IR LEDs can be connected in parallel, the same
way as the IR LEDs are connected. Note however, that the
output current of the PIC is limited to 25mA (This can be
solved by using a transistor, but this descreases the
a PCB: For using a PCB or a strip-board,
check the old circuit page. Check the PCB
designs by Thomas Koglbauer and Antoine Mercier. In order to use the new
circuit, those designs need to be modified a little bit.
The PICs & Kits page contains a PCB image of
the PCB that is found in the kit, which uses the new
Author : Sami Khawam