USB-Interface
In this article I will describe a USB interface for the Casio FX-850P/FX-880P and the PC.
The interface can be used with the following Casio Pocket computers:
- FX-603P, FX-840P, FX-850P, FX-870P, FX-880P, VX-1, VX-2, VX-3 und VX-4
The following Casio models have not yet been tested, but they will probably also work:
- Z-1, Z-1GR
The following Casio models definitely do not work:
- PB-1000, PB-1000C und PB-2000C
Introduction
There are several Interface cable for Casio's from different manufacturers.
You will also find instructions to assemble your own cable on the Internet.
All have in common is that they must be connected to the serial port of your PC.
(c) Knut Mollenhauer
But with new PCs and notebooks this serial interface is replaced by USB ports.
What should you do if you do not have serial ports anymore, and data transfer is needed?
For this reason, we (my brother Uwe and I) looked for a solution to this problem. The main problem is the very seldom-used connection on the Casio. It is a 2x15 pin SMD connector that you can't get in any electronics shop. But the standard USB/Serial adapter could not be used because the Casio do not use real RS232 level (-12V / +12 V), but a TTL level (0V / +5 V) for the data transfer. Because of both reasons, we have to develope our own interface circuit.
USB Chip
First ee have to decide which kind of USB chip should we use. There are many manufacturers. It should be a chip who runs without many extended components. The decision was the USB chip FT232R from FTDI Chip.
The FT232R device offers the following advantages:
- Very good documentation
- Acceptable price, und easy to get
- SMD package
- No programming required
- Drivers available for Windows
- Easy installation of the driver
- No changes are necessary to the transfer program
Interface circuit
The entire interface circuit is built on a self-layouted board.
Instead of the SMD connector is a dual row header 1.27mm SMD used in grid format.
Since this header has no metal casing, of course, there is a risk that the interface can be plugged in upside down.
However, then the component side was down, and this is therefore a grossly negligent handling!
With the new board revision 3.2, all data pins are provided with a protective resistor.
This makes even an accidental reverse polarity or short circuit the terminals any more problems;)
USB connector
We have decided not to solder the USB cable directly to the interface board, but to use a USB connector. This eliminates the costly production of a strain on the cable end, and you can use a ready-made original USB cable connection. The connector is a mini-USB connector. The required USB cable (A to Mini-USB) is included.
Case
We do not need a case. The interface is so small that it can be protected by a shrink film. This saves time and money.
Details: USB-Interface
Details: Connected to Casio PC
Here are detailed macro shots from the front der back and side view.
Data transfer
For data transfer, I use my program MBCasioNotepad.
At this point, a heartfelt thank you to my brother, for his energetic assistance.
Oliver Schoeler has submitted a mount for the USB-Interface!
A second mount for the USB-Interface hat Hans-Peter Beissel submitted!
A description of how to connect my USB-Interface to a Mac has Matthias Schaarschmidt submitted!
That's all for this time. I hope you liked this article. Please sign in my guestbook. If you have comments or suggestions for improvement, then please give me some feedback. If you'll read other interesting articles, please click here.
Ciao,
Manfred
- History
- 08.10.2011 english translation