[Flashforth-devel] Issues controlling flashforth from windows application via usb serial port

[Bob E. <bob...@ti...>]

I have a pic18f4553 board set up for USB serial link. It is going to 
control an antenna tuner from a linx 10 tablet running 32 bit windows 8, 
which also hosts a software defined radio (ham radio).

In windows 8, I have to use zadiq to install the USB serial port for 
flashforth because it is not a registered product - that's OK.

I use teraterm to program  and manually test flashforth. This works 
reliably with inter-char and inter-line delays fitted. The delays seem 
to be needed when loading flashforth from a file, else it can fail. Thus 
I know that extended communication between teraterm and my flashforth 
board works. I've downloaded some large files to further test this.

However, I want to control the flashforth board from a control 
application written in LabView on the tablet. When I use the serial port 
library that comes with LabView, it fails to open the flashforth port, 
although it successfully opens COM1, a normal serial port (but no 
external connector so not usable)

I wrote my own serial port driver in LabView that directly calls the 
windows serial port api. Still not successful - I get a blue screen of 
death after up to 200 messages to and fro with the BSOD message *"STOP 
0x0000000A: IRQL_NOT_LESS_EQUAL – usbser.sys".*

Is the flashforth usb port fully compliant to the standard? Calling the 
api to read the settings of the port completes successfully (returns the 
DCB structure) but writing a modified DCB to the port fails (to set 
9600,n,8,1,n,Xon/Xoff etc ). Doing the same thing to COM1 works. This is 
probably what prevents the labview library from opening the port since 
it assumes you would always want to set baud rate etc.

What I want to know is, has anyone successfully controlled flashforth 
via usb serial link from Windows 7/8/10? What were the details and did 
you have this same problem along the way?

(It's quite possible I have a bug still in my code or that USBSER.SYS is 
corrupt)

Cheers, Bob G4BBY

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