# VFD (or LCD) attached via serial port (usb to serial)



## larry98765 (Sep 11, 2006)

Hi All,
I got a Vacuum Flourescent display (VFD) for a Basic Stamp microcontroller. It's working fine with the microcontroller, but I'm experimenting with sending commands to it directly through my mac usb port. (Instead of using the microcontroller.)

So far:

1) I have power to the VFD using a carrier board and battery.
2) I'm using a keyspan usb-to-serial converter (and the associated driver)
3) I'm connecting pin #3 on the serial adapter to the serial input pin on the VFD

I want to test my connection using a terminal program such as ZTerm, QuickTerm or even the command line's "stty". But I'm stuck on the following point:

The VFD needs to be sent certain commands in order to be "powered up" and for things like carriage returns and clearscreen etc. In Basic Stamp microcontroller world, those commands look like  this:


```
SEROUT VFD, Baud [ $1F, $28, $77, $10, $01 ]
```

and text would be sent to the VFD like this:


```
SEROUT VFD, Baud [ "Hello, World!" ]
```

So my question is: how do I write those same commands using something like Quickterm, ZTerm or STTY?

I know this stuff is pretty obscure, but hopefully someone out there has done this before?

Thanks


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## MisterMe (Sep 11, 2006)

An ASCII terminal is an ASCII terminal. You need to communicate with your USB port as though you were using a null modem. To do this, you need a terminal app that communicate via USB. If you were a real Unix guru, you could redirect *Terminal* to your Mac's USB port, which would be the most convenient. *Zterm* can only communicate via USB if your microcontroller has a MacOS X driver that redirects serial traffic to USB. *QuickTerm* is supposed to communicate through a USB-to-serial adaptor. It appears not to require a vendor-supplied driver. If *QuickTerm* does not do the trick, then you might look into *MacWise*. It is not free, but it appears to do everything including communicate with serial devices via a Keyspan USB-to-serial adaptor. My suggestion would be to forget about *Zterm*. *QuickTerm* is now UB and free. *MacWise* gets updated every two or three hours. Between the two, you should find a terminal emulator that does the trick for you.


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## larry98765 (Sep 11, 2006)

MisterMe said:


> An ASCII terminal is an ASCII terminal. You need to communicate with your USB port as though you were using a null modem.  To do this, you need a terminal app that communicate via USB.



Thanks for your reply.
I have a USB to Serial adapter and the appropriate driver. ZTerm DOES recognize the port. So don't I have a terminal app that's communicating via USB?

The real meat of my question is not how to connect, but what to send.


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## MisterMe (Sep 11, 2006)

If *Zterm* recognizes the USB port, then it is doing its job. As for what to send, well you are the one with the manual. Read it and follow instructions.


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## larry98765 (Sep 11, 2006)

Hmm. There was no manual. Sorry my question offended you somehow.


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