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USB + STR9 + VB

electrogvlieghe
Associate II
Posted on October 10, 2008 at 10:34

USB + STR9 + VB

4 REPLIES 4
electrogvlieghe
Associate II
Posted on May 17, 2011 at 09:56

Hello,

I develop an application with the STR9-Comstick. The idea is to control the I/O ports with a program in Visual Basic through the USB-B connector near the pins of I/O ports.

Which dll use for that for the enumeration ?

The first application will be to generate a TTL signal for differents frequencies through a pin of the I/O ports. Is there a way to program it in C (TTL signal) for the STR9 ? And so the program in VB ?

Thanks

dhoyen
Associate II
Posted on May 17, 2011 at 09:56

Hi,

Ok, Sorry for the misunderstanding...

To be right with you, i never played with USB, including PC side or embedded side. I can't help you for this subject. Seems not the easiest task, it's sure...

For the choose of an externel ADC, you have certainly a good reason, else, the STR912 embedded ADC could be interesting, according to the fact, it's possible to use a timer to clock it, and also a DMA to transfer data, with 0% or less than 1% CPU load.

In my project, i m able to sample at 1MS / sec. (only 1 channel;-( ), for 16Ksample, using a 32Kram buffer, and with a excellent time accuracy. If the bandwith of the USB 2.0 is 480Mbps (really optimistic, but should be realist for 50 Mbps), you could sample at this frequency without time limit 😉

Damien

dhoyen
Associate II
Posted on May 17, 2011 at 09:56

Hi,

because i know nothing about VB with Windows, i will not reply to these question about USB and DLL.

BUT :

To program a ARM processor, in VB, it's clearly a bad idea

(no support, no ST library, no open source project, low resource and i think: simply: no compiler is available for this target).

Anyway: Do it in C.

For your project, use a STR9 hardware timer (i have a stick, only 10 pin are available outside, i hope it's possible to root 1 timer signal output (PWM))

Don't do it in software, he will not work (especially when you will try to increase the frequency)

Best way, if it's your 1st project, take a look and set your 1st project from working example. After, just change what you need.

You can use as environment for the STR912 :

Yagarto / Open OCD to program it via the embedded JTAG controller inside the STR912. Both are Opensource and legally available, and run under Windows.

Regards.

Damien

electrogvlieghe
Associate II
Posted on May 17, 2011 at 09:56

Hello,

Thanks for your answer. i don't want to program ARM processor in VB but control the code in the ARM processor by VB.

My final project is to program a sequence acquisition for an extern ADC board connect to STR9-Comstick (via I/O ports). The program in VB will retrieve samples of signal via USB and so to view and analyze the signal on the computer.

My first application for generate a TTL signal for differents frequencies through a pin of the I/O ports was a training for learn the str9-comstick.

So i would program my str9-comstick in C by Hitop software for generate TTL signal and my program in VB will send instructions by USB to STR9-Comstick for change the frequency of the TTL signal.

Regards

Vlieghe Guillaume