AutoHotkey Community

[Lesley]

hello everyone, I am just a mere student compared to all the geniuses on this forum like aobrein & trenton_xavier. I have a project and I need to be able to send strings to the lego NXT. The nxt bluetooth protocol involves hexadecimal values, and frankly i dont understand it. The protocol can be seen after downloading the bluetooth developer kit in the link below

http://mindstorms.lego.com/en-us/support/files/default.aspx

I have been able to use aobrein code, the code NOT involving the PORT.dll to establish a connection between my pc and the lego NXT. Now, I just need to be able to send string or integer( just a code to be able to send "a" for example).

Please please I need your help as this is my final year project.
Thank you!

[aobrien]

Hi Golericas,

I don't think that it will be possible to do what you want (serial port snooping) with this script - not very easily at any rate. I think Trenton's idea is best use some other software to do the sniffing.

aobrien

[aobrien]

Hi Lesley,

This Serial Port (COM) Script can send/receive any 8 bit combination on any serial port. If you wanted to send the string 'a' you would have to look up the ASCII equivalent. http://www.asciitable.com/

0x61 is the equivalent to 'a'. Whenever someone sends the string 'a' they are actually sending the hex code 0x61 or the binary code 01100001.

So, if you wanted to send 'a' you would use the following command... Write_to_COM(0x61)

This is all documented at the beginning of the script. If you are still having problems then post your script and what you are trying to do and we can go from there.

aobrien

[GerryT]

Hello all, I would like to hopefully add this to my init string,

3 standard port <Flow Control Options>,

-NONE
-HARDWARE
-XON/XOFF


Can someone please show how these options work into COM_Settings string?

[Franz]

Greets > what does the DTR=OFF optoin stand for.. and this value otherwise may contain?

[trenton_xavier]

@GerryT

Here's the commplete BuildCommDCB function as described on MSDN (converted into AHK-ish):

[Guppy]

Thank you for this console script, it is quite excellent and versatile.

I have a quick question - how do I retrieve the Device Description Value property from a selected COM?

[aobrien]

Hi Guppy,

I'm not even sure what the Device Description Value is... I'm guessing that it is describing the device settings.

Anyway, this script isn't capable of retrieving the COM port settings. To do that would most likely require a separate DLL call.

Sorry,
aobrien

[wiseley]

[HelpAHK]

Thank you everyone, ... all folks making this easier to understand and better.

I am hoping someone can take some time to understand why problem described below is making my life miserable.

I am connecting this to a laptop, which hooks into an automobile engine performance monitor. It generates data on engine speed, battery life, etc.

Basically, I am trying to read data with Read_From_Com(Num_Bytes).

It works perfectly with this script. EXCEPT - if I unplug the device, and restart the script, I get garbage out of it. Even if I reboot I still get garbage out... somehow the script crashes the hardware.

HOWEVER, if I run something like Hyperterminal, ... and connect to it, the device works again, produces clean data. Everytime! So if I re-run the script, it works there again! Un-plug / re-plug hardware and run hyperterminal does not produce this result. It works & never a problem... This script works, only on first run.

What could this script not be doing to set things up?

I am really confused and open to any suggestions on what I can try. Thank you all for any ideas.

[aobrien]

Hi HelpAHK,

I think that the problem might be in the Serial Port buffers in the PC. Read_from_COM() simply retrieves data from the buffers. If you don't close the COM port and/or flush out the buffer then you could get out of sync and everything would look like garbage. Sounds like HyperTerminal is taking care of the housekeeping. Did you try CTRL-F1 (close COM port) before you removed the cable?

I have an application that reads temperature from a multimeter. The multimeter constantly streams data regardless of what is connected. In this case I take a snapshot of the data and figure out where the starting point is then I take decode everything from that point.

Are you using the script exactly as posted or did you take the functions and make your own script? Can you post your code? If not then you could send it to me in a PM and I will look at it and help you debug.

Regards,
aobrien

[HelpAHK]

Aobrien, thank you for the analysis which seems spot on to what might be happening here. I am utilizing the functions here just as they are with no further modifications. The garbage appears, even if I properly shut down (Close Com Port), then un-plug. Strangely, even if I re-boot, the garbage is still there. So the Windows buffer must keep it in state somewhere, and... yep, running Hyperterminal seems to do the trick to 're-set' things.

So I imagine, maybe there is something I can do up-front in my script to clean house, so things can get going right. Any ideas?

[aobrien]

Hi HelpAHK,

Can you give me 3 things to look at?
1) The ASCII output in passing mode
2) Data in the passing mode
3) Data the failure mode

Then we will be able to compare the information to see if it is some sort of buffer/synchronization problem.

To enable data output make the change to the script shown below. You need to change the IF (1) to IF (0).

[HelpAHK]

Thank you! I am working on this and will report some clear results soon. Thank you!

[haichen]

Dear aobrien,
thank you for your script! I used it to read data from a cheap weathersensor. It works very fine.

I made your functions stdlib compatible. Therfore i changed the names to PORT_ because there is already Seans COM_ bib.
But of course if you like to have it renamed i will change this. I got rid of the globals and everything work like expected. Hopefully ( I tested the readcapability only).
The only thing i changed was mentioning of the COM-number in the errormessages.

Maybe this is useful for you and others.

PORT.ahk (standardlib compatible)