PICDEM FS and USB

[Gab25]

Hi,
I'm new to using usb and I must write a C code that read data from the usb port of PICDEM Full Speed demo board (PIC18f4550).
What software can I use? I need to write a little driver for exchange data with the board?

thanks

[Bruce]

Do you need to write "C" code for the PIC or the USB host application?

I have PBP & Visual Basic code for the following if you're interested
http://www.rentron.com/images/USB_MAIN.gif

[Nestyplus]

Do you need to write "C" code for the PIC or the USB host application?

I have PBP & Visual Basic code for the following if you're interested
http://www.rentron.com/images/USB_MAIN.gif

Hi Bruce,

Did you used the HIDFS Maker by trace system in this application of yours for the PIC USB firmware program side?

Thanks

[Bruce]

No. I used EasyHID.

[rhino]

Do you need to write "C" code for the PIC or the USB host application?

I have PBP & Visual Basic code for the following if you're interested
http://www.rentron.com/images/USB_MAIN.gif

This looks like a good example to put in your example projects page.... I know I would certainly like to see it. By the way, I don't know if you hear it enough, but those examples are excellent and really help beginners understand how to get started..... so in other words.... THANK YOU!

[Gab25]

Hi Bruce,

I must write the USB host application...only read and display bulk data from the pic in CDC class.
If I use a generic class i must write a driver, it's correct?
Can I go with the CDC class or an HID class to 1,5 Mbit/s ?

thanks

[Bruce]

I don't see why you would need to write your own driver. CDC class can use the Windows generic driver already available with Windows.

Microchip & PBP both offer example programs for CDC class USB communications.

As for data rates, download & review the USB 2.0 & CDC class documents from http://www.usb.org These explain in detail what data rates you can expect depending on the USB transfer type you're using.

You might also want to take a peek at Microchips' AN956; Migrating Applications to USB from RS-232 UART with Minimal Impact on PC Software.

Any route you take is going to involve some serious study time. USB is pretty complex.

[Gab25]

I tried to use the microchip example "Run time linking" but I can't see the correct value of the potentiometer.

#define RD_POT	0x37			
send_buf[0] = RD_POT;				
send_buf[1] = 0x02;              
SendReceivePacket(send_buf,2,receive_buf,&RecvLength,1000,1000);
printf("\n%x %x %x\r\n",receive_buf[0],receive_buf[2],receive_buf[1]);

If I try to read the Firmware Version it works great. Any Idea?

Another part of the example:

switch(dataPacket.CMD)
{
case READ_VERSION:
dataPacket._byte[2] = MINOR_VERSION;
dataPacket._byte[3] = MAJOR_VERSION;
dataPacket._byte[4] = MINOR_VERSION;
dataPacket._byte[5] = MAJOR_VERSION;
counter=0x06;

Why I can't send 6 byte or more...but only 4?

Thanks and sorry for my english