...Is to make two Palm IIIc become wall-mounted , and present an
convenient home automation menu, with the most used functions.
Every IR code is received by an computer that controls "everything"
using IR , X10 and TCPIP
Disconnecting battery connector will cause total loss of memory, you
should use the free "BackupXfer" to do a complete backup of your Palm
Opening your Palm and messing with it will void any warranty - if any.
/(this are old, discontinued devices)
If you test the device while disassembled - be careful with the
high voltage line (backlit) - it is switched to few hundred
volts, and will not only be able to give you a shock, (not lethal to
healthy people) but (even worse) this voltage can travel thru your
fingers and destroy the electronics instantly.
Locating IR signal.
First : locating the TX signal , that usually controls the LED
driver inside the SIR2 module - it is the second pad from right.
I soldered three twisted enamel-isolated wires to it - this is what
I'll call the TX signal from now on...
The blue line shows a pad that is GND
The red, shows a pad that is Vbatt - battery voltage - by using it - I
will not disturb/overload the 3.3v regulated power line that this
Choice of components:
I did not had any IR diode in house this evening, so I used one diode I
took from an old remote control.
Only one additional component is really needed. - an digital MOS-FET.
I chose the FDV303N - an SO8 digital N-channel FET with 2A peak
current.(its perfect - as IR remotes sends not more than 150us long
This MOS FET is also ESD (Electro Static Discharge) protected, and
therefore fits well to the job - I plan to have an external diode.
This picture shows the SO8 size - compared to a jumper, a "thin"
wire and a match.
Putting it all together:
Remember: it's no problem if you reverse the IR diode - it won't
work - but nothing will go wrong.
Solder the FDV303N's Source pin to the TX signal pad (the second pad
from right in the MINI SIR2 module.).
Connect the FDV303N's Gate pin to the GND pad. (see picture with blue
Connect the +Vbatt pad to the IR LED's Anode. (see picture
with red line)
Connect the FDV303N's Drain to the IR LED's Cathode.
It should look somewhat like this:
The circuit should work now, no matter what IR software you use
/(OmniRemote pro , ProntoLite or other) this circuit will work..
This circuit is THIS powewrful:
- you can notice the IR diode(s) will get hot after a while with much
- you can connect two diodes in serial for greater range.
- you can connect two or more diodes in paralell for greater
- this MOS FET provide spikes up to 2A - and the battery +
capacitors can deliver it - it's awfully much power.
In case you would like to use the Palm as a mobile device - You can do
Just glue an (2.54mm pin header) connector in side the casing, this
connector can then take a IR diode when needed - stright pins or in any
External connector with a bent diode that will, when
mounted on wall, point in the direction of my living room.