LaserKeyboard with serial out

mrn · Post by **mrn** » Fri Jan 27, 2006 3:44 am

Hello , this company says their Laser keyboard has a serial out:

.. Bluetooth Hot Plug-Funktion oder seriell..

http://www.plawa.com/mobilities/celluon ... rkeysmart/
does any of us have experience with this thing?
Do you know the way it communicates with the machine?
(I am keen on virtual keys :)

Viper8896 · Post by **Viper8896** » Fri Jan 27, 2006 6:29 am

i saw something like this on a gadget show on tv once. there amazing. but u have to be at the table u cant do anything like texting on the move

danzel · Post by **danzel** » Fri Jan 27, 2006 7:40 am

you can turn the page into english ;) there is a language pop down box on the left hand side.

By means of a laser, the Laserkey CL800BT projects a full-scale keyboard equipped with a mouse feature* onto any opaque, flat surface. The keystrokes are then identified based on the combined input of a sensor and an invisible infrared layer. The connection to PDA, Pocket PC, Smart Phone or PC is set up via a user-friendly Bluetooth hot plug function or via the serial port. The pocket-sized CL800BT is powered by a compact, powerful Lithium-Ion battery.

If it really can plug in via serial we could possibly have one working on the psp.

glynnder · Post by **glynnder** » Sun Mar 05, 2006 12:25 am

wow cool, shame they're nearly as expensive as a new PSP lol!!!

Art · Post by **Art** » Tue Mar 07, 2006 7:30 am

I found LUA required a huge character pacing with serial comms through
the PSP serial port. So great in fact, that any device that sent more than
one byte in each burst would only have the PSP recognise the first byte.
(for short two or three byte nano commands)
That is the only reason why my GPS program requires a microcontroller
buffer to slow down comms between the GPS device and PSP.

I have not used the serial port with C language yet to find out if it was just
a LUAplayer limitation or SDK problem. This may have even been corrected
in a newer version of LUAplayer for all I know.
Art.

Dr. Vegetable · Post by **Dr. Vegetable** » Tue Mar 07, 2006 8:15 am

I had a similar problem with limited throughput in a C application that I wrote to get input from an IrDA keyboard. It turns out that the way my main loop was written, I was only reading one byte from the serial port per vertical sync. When I changed the program to keep reading bytes until the input queue is empty, my program suddenly had no problems keeping up with the input stream. I don't know if this is the issue with LUA, but it seems to be a common programming error on this platform.

You are more than welcome to use my keyboard sample program as a starting point for re-writing your GPS application in C.

groepaz · Post by **groepaz** » Tue Mar 07, 2006 1:34 pm

also if you want to transmit "real" data (not just some debug text or sth) over the psp serial line you should definetly use some kind of software handshaking (XON/XOFF) plus maybe even an additional layer of a traditional transfer protocol (zmodem?).....lack of rts/cts really bites :=P

Art · Post by **Art** » Wed Mar 08, 2006 7:48 am

When I changed the program to keep reading bytes until the input queue is empty, my program suddenly had no problems keeping up with the input stream

I suspected this,Shine said something similar to that, but also thought that if I went
about fixing it, I might as well wait until I can make the program better in C.
I am starting from the beginning "hello world" with C.
Thanx, I will have a look at your serial program, but not at this time.

Is there a baud rate limitation at the headphone serial port preventing you
from connecting the battery serial port to it with two diodes, one wire and no MAX232?
It would be nice to use the PSP as a tool for hacking itself, and you could
save money on wire with the ground connection.
Art.

Dr. Vegetable · Post by **Dr. Vegetable** » Thu Mar 09, 2006 5:34 am

Art wrote:Is there a baud rate limitation at the headphone serial port preventing you from connecting the battery serial port to it with two diodes, one wire and no MAX232? It would be nice to use the PSP as a tool for hacking itself, and you could save money on wire with the ground connection.

This would probably work. In fact, you could probably just run a single wire from the middle pin straight into the PSP SIRCS port Receive pin. (You might also need the ground connection.)

You should only need diodes if you connect the PSP's Transmit line. But if you were planning to TX to the battery COM port, it might cause unexpected results on the subject PSP, so you'd probably want to use two PSPs for stuff like that. A second system would also be necessary to monitor things like battery insertion and power on/off behavior.

But don't blame me if your PSP catches on fire!

Art · Post by **Art** » Thu Mar 09, 2006 1:53 pm

You should only need diodes if you connect the PSP's Transmit line.

I assume the aim would be to use the PSP to emulate the PSP battery port
or the PSP battery, depending on what you wanted to study.
In your case I suppose it's the battery since the PSP isn't going to tell
the battery that it wants to go into service mode.

Maybe more people would try it if it was done this way. Maybe not.

I still haven't looked at the maximum baud rate of the PSP serial port.
Art.

Art · Post by **Art** » Thu Mar 09, 2006 2:04 pm

I forgot how a lot of people don't like to make physical things.

There is a ready made device called a season interface that was made to connect the
one wire comms between the smartcard and CAM in a sat TV decoder to
A PC so that the PC can emulate the smart card, but the smartcard comms
is 5 Volts, so it uses a MAX232.

There was a poorman's version of this interface that uses transistors called
a Jomac interface. It would take minimal effort to use one of them to connect
the PSP to a single PC com port, or PSP com port.