USB troubles

Zap-o

I made a prototype board and using the schematic included in this post and a propeller. I am communicating to a terminal program on a computer. I cant understand and its driving me nuts - when I exit the program running on the computer and restart it I loose coms with the propeller.

Any ideas?

Zap-o

Oh i forgot to mention that I must press the switch to program the propeller. Otherwise its an open and my thoughts were that I would not reset when the cable was removed from the USB port.

Mike Green

What do you mean "lose coms with the Propeller"?

When you exit the program, it will close the COM port in use. When you restart the program, it will attempt to open the COM port.

Zap-o

Yes Mike when the program exits it seems as thought the propeller gets stuck. for example: I can set the prop code to toggle a led. When the program (computer side) is exited the led will stay solid instead of blinking or the led will shut off depending on the time its shut off.

Strange eh?

StefanL38

not to strange if you use the serial connection on the "programming" pins 30,31

maybe the RTS-line is already toggled when closing the PC-application
it surely is toggled when you open the comport new and the toggling will reset the prop

does this appear if you store your program to EEPROM too ?

try PST.EXE from parallax which does NOT toggle the RTS-line when you open/close the comport

best regards

Stefan

MagIO2

What does the propeller side of your prototype board look like? Is RST pin connected to a pull up resistor? If not you have a free floating reset pin which can cause problems.

Cluso99

Above posts referring to RTS should be referring to DTR. Most Terminal programs turn DTR on when they run, resulting in a prop reset - I presume your circuit diagram connects to the prop reset and also you have a ground connection as per the propplug circuit. You should also have a series resistor of about 150R in tx and rx lines.

Now, your problem is most likely DTR toggling in the Terminal program you are using. Try PST (Parallax Serial Terminal) or PropTerminal. These are built with knowledge of the DTR reset to the prop and they release the com port when they lose focus (switch back to PropTool).

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· Home of the MultiBladeProps: TriBladeProp, RamBlade, TwinBlade,·SixBlade, website
· Single Board Computer:·3 Propeller ICs·and a·TriBladeProp board (ZiCog Z80 Emulator)
· Prop Tools under Development or Completed (Index)
· Emulators: Micros eg Altair, and Terminals eg VT100 (Index) ZiCog (Z80), MoCog (6809)
· Search the Propeller forums (via Google)
My cruising website is: ·www.bluemagic.biz·· MultiBladeProp is: www.bluemagic.biz/cluso.htm

Timothy D. Swieter

If you look at the attached schematic, the Reset Switch and the NPN transistor are in series. That doesn't make sense to me, unless it is not a Reset Switch but only an enable to allow the USB/FTDI to do resets with the DTR when desired.

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Timothy D. Swieter, E.I.
www.brilldea.com - Prop Blade, LED Painter, RGB LEDs, 3.0" LCD Composite video display, eProto for SunSPOT
www.tdswieter.com

Zap-o

Thanks people for the help. It looks as though my board has a short on it and was causing the problem. It works fine now after I removed the shorted area.

Again thanks