50 replies to this topic

[far2055]

Do you have raw (enough) serial port access in the CP?

Really I don't know. I never have written a program for CP. But I think CPSDK gives complete access to serail port. Ask the others!

Is the MicroController and your Flash big? Can I open the ClassPad and put them inside?

I think it isn't possible to put the flash inside the CP. It's dimension should be about 6x6x3 (LxWxH) cm.

[far2055]

Oh. As I see today my page didn't load completely yesterday! someothers have the same idea about using the serial port(3pin port).

The ways you have to connect external memory would be through USB or "3-pin", but do you know the protocol of the 3-pin port? Do you know how to decode it, convert it and make it usable for a USB mass storage device? Do you have any knowledge of electronics at all?

As I guess the 3pin port is a complete TTL serial port. I read some part of SH-3 datasheet and found that it has a build-in serial port. So why casio don't use it as 3pin port?

Check commiunication settings. You will see "speed(3pin)" option uses standard speeds for serial ports.

By using max232 I built a cable for an Algebra FX 2.0 to connect it to computer through 3pin port(so both ports are using serial protocol,the only diffrent is about their logic voltage level(CP:0->0v 1->+5v but RS232:0->-15v 1->+15v)).

And at last I don't think casio encrypt data in software layer(I mean send and recive function shouldn't modify data So there is no need to hack the OS or writting a decrypter)

I have a basic question:
What do the pins on 3pin and USB (4pin) socket do?
Which one is affined to send and which one is affined to recieve data?
Are there any null (ground) pins?

3pin uses 3 wire:

1 for sending serialized data. (TX pin)
1 for receiving serialized dat. (RX pin)
1 for making a base for the voltage measurment in both systems. (GND)

USB pins:

1 for VCC supply.(+5v)
1 for GND.
1 for making devices synchronous.(Clock or CLK)
1 for sending/receiving data.

For a connection, how many pins at last is needed?

as you can see for a full-duplex (in persian: 2tarafe) connection at least you need 3pin. For a Half-duplex you need 2pin.
It completely depend on the protocol you choose to communicate. it is possible to make a full-duplex connection by using just 1 wire but it is not common and there is no standard protocol for doing that and not reliable.

To Behnood:
salam. shoma kodoom daneshgah dars mikhoonid?

[Andreas B]

As I guess the 3pin port is a complete TTL serial port. I read some part of SH-3 datasheet and found that it has a build-in serial port. So why casio don't use it as 3pin port?

They probably do, as in the fx-9860G.

And at last I don't think casio encrypt data in software layer(I mean send and recive function shouldn't modify data So there is no need to hack the OS or writting a decrypter)

I checked out the SDK docs (impressive), and you seem to be able to use the 3-pin port. From what I knew about the fx-9860G, it's BASIC functions for 3-pin port access were not raw, and you would have to trick it into thinking it was talking to another calculator.

USB pins:

1 for VCC supply.(+5v)
1 for GND.
1 for making devices synchronous.(Clock or CLK)
1 for sending/receiving data.

The USB bus has one pair for data (D+, D-) used together, and one for GND and VCC.

as you can see for a full-duplex (in persian: 2tarafe) connection at least you need 3pin. For a Half-duplex you need 2pin.
It completely depend on the protocol you choose to communicate. it is possible to make a full-duplex connection by using just 1 wire but it is not common and there is no standard protocol for doing that and not reliable.

'1-Wire' (two pins) is the name of a protocol using just two wires, but it is not especially quick or relevant to this.


It is still a clumsy way to extend the memory, as you will have to build it yourself and it probably won't fit in the case. You have to use your own add-in to copy data from/to it too. You could just as well use the computer. But I guess it is fun to hack It is a lot more work than assembling a level converter from a finished schematic

Good luck.

[far2055]

-->

It is still a clumsy way to extend the memory, as you will have to build it yourself and it probably won't fit in the case. You have to use your own add-in to copy data from/to it too. You could just as well use the computer. But I guess it is fun to hack It is a lot more work than assembling a level converter from a finished schematic [/quote]

We just need to extend the Flash memory. We need some more flash memory to put big programs like a dictionary on it and We try to do built a portable extender not something like a desktop computer!
An small one that you can put it in your pocket and every time you need plug it in to your classpad and waiting for some seconds for transferring data and disconnect it again and continue your work.

------------------
Andreas B thank you for your notes.

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[far2055]

I have some surprising news!

I found a development kit that use a MicroController(a PIC one) for connecting a CompactFlash card to other devices(IDE is ready so it is possible to use it as a hard drive too!).
So it is very easy to adapt it and extend it to use 3pin port for communicating with classpad.(even The Source Code is available too! We should just modify codes for adding serial port communication support.)
There is just 3 mistake:

1)The development kit needs 9v power supply.(9v power supply is needed when using IDE. So simply we can add a switch to switch between 5v and 9v power supplies. When using IDE put the switch on 9v and when using 3pin put the switch on 5v battery supply.(It uses LM7805 voltage regulator.))

2)Using our own filesystem make the CompactFlash unusable with IDE interface.So it isn't possible to read/write to the CompactFlash by using PC.(Exept that someone write a program that read/write data from CompactFlash in ordinary filesystem format for classpad.)

3)The CompactFlash is really expensive! It is a little cheaper than classpad!(If we use its schematic and build it ourself, then it will be so cheap! Witheout the CompactFlash Card it worth about 15~20$!!!)

So please tell me what do you think about CompactFlash development kit?

http://www.armanet.c...mpactflash.html

[kevinator9]

Now we are getting somewhere!

[neontiger]

Yahooooooooo!

I hope that idea goes fine!

[kevinator9]

Me too, I took it as far as I could... I don't know any programming languages or any hardware techniques.

[kevinator9]

http://www.dutchforc...mp;#entry105755
Check the post! Shows a chip that you could use...

[far2055]

http://www.dutchforc...mp;#entry105755
Check the post! Shows a chip that you could use...

Thanks for your help. I think it is better to have a CompactFlash Card instead of a Memory chip.
CompactFlash card is very popular.

[kevinator9]

No problem, I really have no idea what would be easier or more effective. Just another idea.