Testing PowerComms

Hi

I have built the board.

I have tested with loop back and Hyperterminal on Com1 and get echo OK

I have loaded the RepRap software into Windows thanks to DanP's posts.

Reprap software appears to load OK

I select Tools - Stepper Exerciser and get error message:-

There was an error opening /dev/ttys0
etc.


The underlying dos command window shows:-


C:\reprap-host-0.8.1>java -Xmx384M -jar Reprap.jar
Opening port /dev/ttyS0
Stable Library
=========================================
Native lib Version = RXTX-2.1-7
Java lib Version = RXTX-2.1-7

Is this normal and I need to connect a stepper board or have I something wrong in my setup?

Edited 1 time(s). Last edit at 07/23/2007 06:15AM by Ian Eagland.

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Regards

Ian

You need to change the serial port from /dev/ttys0 to COM1 on Windows.

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[www.hydraraptor.blogspot.com]

Hi

Thanks, that solved my problem.

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Regards

Ian

Need the smart ones here to help me out, I've built the power/comms board all looks good (sort of), but no echo. Here are my measurments between pins, first with no serial port connection and no jumper on T and X.
15 to 16 is 5.10V
15 to 14 is -10.4V
15 to 13 is 0.0V
15 to 12 is 5.10V
15 to 11 is 5.0V (shouldn't this be 4 or 4.5V)

With serial port connected and jumpers on T and X.
15 to 16 is 5.10V
15 to 14 is 10.4V
15 to 13 is 0.06V (something wrong here I think)
15 to 12 is 5.10V
15 to 11 is 5.0V

only thing I can think of is that my MAX232CPE IC is bad, but I really have no clue where my problem lies, any help would be appreciated.

Thanks

First of all I wouldn't be too worried about the voltage on pin 11 when there is nothing connected to P3. It is an input to the max chip with a 400K internal pullup resistor to 5V. The voltage you get will depend on how good your meter is, i.e. how much current it takes. The wiki should probably say 4 to 5V depending on your meter, or just not mention it all.

Pin 13 having close to zero on it is a problem. That signal should be coming from your serial port and should be negative when nothing is being transmitted. If your max chip is socketed try removing it and measuring the voltage on 13. If if is still not at least 5V negative suspect your serial cable and then your PC's serial port. Try linking 14 and 13 with the max chip removed. You should be able to get an echo. Also try measure the voltage on 14 with no max chip. If that is negative it is likely your cable is swapping pins 2 and 3.

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[www.hydraraptor.blogspot.com]

Thanks Nophead, I was getting a negative voltage of 10.04 on pin 14 with chip removed, jumped 13 and 14 and got an echo. Ran off to get a new cable and things are working fine now, which surprises me as I thought for sure the chip would be scrap seeing that the first cable was bad. Anyway now I can move on to the next board, thanks again for your help.

Yes it is quite common to get TX and RX swapped with RS232 but I have never known it damage anything.

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[www.hydraraptor.blogspot.com]

awesome! its good to see a problem be easily resolved. nophead... would you mind writing up a simple problem / answer troubleshooting type thing that we could put up in the wiki?

Ok, I will have a go. I would like to get to the bottom of Kai's problem first though. That's a real puzzler.

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[www.hydraraptor.blogspot.com]