USBDemo, something to learn USB a little bit

[Darrel Taylor]

When I compile it gives the following errors.

Error[118] c:\progr~1\mecani~1\mcs\usbdemo.asm 87 : Overwriting previous address contents (0000)
...

What to do if i get "overwriting previous address content" error message?
http://www.picbasic.co.uk/forum/showthread.php?p=6775

Also out of interest, I am using a 4Mhz Resonator but in the code it is: DEFINE OSC 48

What is that about?

The 18F/USB PIC's have an amazing oscillator/PLL structure.

With the proper CONFIG settings, You can use any crystal that's a multiple of 4mhz (4,8,12,16,20) and still have a system clock of 48mhz.

If the timing doesn't work well with your program, you can also have 48mhz going to the USB module, and 4/8/12/16/20/24/32 mhz going to the system clock.

It all depends on the CONFIG's.
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[kiwipiper]

I commented out the four offending lines in the 18F4550.INC file and now don't get any errors. However, still get a error message from windows when I attach the PIC

Messages are: Found New Hardware. USB Device
USB Human Interface Device
A problem occurred during hardware installation. Your new hardware might not work properly.

I have tried USBDemo.exe and HIDmonitor.exe neither of these seems to see the PIC.

Any suggestions as to what I should try to do now to find the fault. At this stage I have not connected the push buttons or the trim pot to the breadboard but this shouldn't affect the pic being recognised as a USB device.

P.S. I have the USB connected to 18F4550 in the following way. D- to pin 23, D+ to pin 24 and the -ve usb connection and the USB case connected to vss. I have not connected the +ve usb connection to anything.

[kiwipiper]

Forget my last I have figured it out ....... a very happy man here.

I had left out the .47uF cap on Vusb. Connected this and all is working.

Will now have a serious play with it, which I sure will create a bunch more questions.

Thanks for all your help Darrel.

[kiwipiper]

This One for Darrel Taylor. My question is how did you get on modifying the USBDemo program from VB to Delphi. I am much more comfortable working in Delphi than VB and would be really interested in any examples of Delphi Code for this project. I found a good component at http://www.soft-gems.net/index.php?o...d=14&Itemid=33 and have had some success in using it to connect to my PIC but my limited programming ability slows me down a fair bit, although I am learning a lot. If I had a working example in Delphi I am sure it would help me understand what is going on much better.

A second question is how do you put a serial number into the program. I have been playing around with the DESCUSBDemo.asm
file and tried to put a serial number into the code. Here is what I did:

; serial number
String3
retlw (String4-String3)/2
retlw DSC_STR

retlw '4'
retlw 0x00
retlw '3'
retlw 0x00
retlw '2'
retlw 0x00
retlw '0'
retlw 0x00
retlw '8'
retlw 0x00
retlw '8'
retlw 0x00
retlw '8'
retlw 0x00

Not working. Any suggestions.

[Darrel Taylor]

Both questions can be answered with EasyHID.

The serial number is entered on one of the setup screens.

And EasyHID will make a "Starting" program for either VB or Delphi.
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[kiwipiper]

Thanks for that Darrel .... I did not understand the significance of EasyHID when it was being discussed in this thread earlier on. Making some real progress now and think I should be able to recreate the VB USBDemo.exe in Delphi. Very exciting stuff this USB.

[Momboz]

Thanks for that Darrel .... I did not understand the significance of EasyHID when it was being discussed in this thread earlier on. Making some real progress now and think I should be able to recreate the VB USBDemo.exe in Delphi. Very exciting stuff this USB.

Hi
Here is an adaptation of Mister_E USBDemo but in Delphi. It's not completely finalised but it works. This example bases on the PICPROTO-USB board from MELabs (you can get all the information on this board from their web site).

It's PIC18F4550 @ 20 MHz based. I hope the rest is self explanatory. PWM signal is on PORTC.2.

If you need more info, just let me know. Please, take into account I am not very often on this forum, i.e. please, allow longer reaction times in case you need feedback.

Have fun