USBDemo, something to learn USB a little bit

[charudatt]

Here's a small contribution from my end to support the good work.

Thank you steve for the help

regards.

[skimask]

Here's a small contribution from my end to support the good work.

Thank you steve for the help

regards.

And I would think that a similar dev board for a '4550 would be practically the same except for the obvious pin differences...
I hope so...'cause that's what I'm building...still waiting on the '4550's though...

[mister_e]

Sure,

There's just a little something i would point so far. Yes the 1.5K is recommended if you don't enable the internal one as i did. Now i think the generic code do it for us... but for safety sake i did it in mine. the two 100nF could be replace with a 470nF. In some occasion it seems to be better when using a higher value. EasyPic 4 use 2X110nF but i changed it. It's just for safety sake so far. If it's working for you... use it

Now, the Darrel's code mod comes really handy. It free 1 timer... really interesting...

Instant Interrupts - Revisited, post 148
http://www.picbasic.co.uk/forum/show...&postcount=148

Thanks to everybody posting in here!

[vacpress]

Does anyone know if i can substitute a different value for the 470nf capacitor that pulls the usb+ to vcc? Somehow I haven't got any nf value capacitors - plenty of pf, uf...

I read a post somewhere at some point where a guy said he was using a 2.2uf and it worked ok.

Thanks

Robert

[vacpress]

Hey!

First, Mister E, thanks so much for putting this together, I can tell it will be a huge springboard for me, if i can ever get it to work!

I already mentioned that I am using a 10pf capacitor instead of the 470nf one specified. I haven't got any nf capacitors at all! oi!

Anyways, i loaded the included .hex(still cant compile it from source) and my computer recognizes an 'unknown usb device', not a HID device.

Ive got a 4mhz resonator on there.. i tried it with a 20mhz and it didn't seem to do anything.

Any advice please?! I took the day off work to do this stuff today, and it is frustrating!

Thanks!

Robert

[vacpress]

i got it to work! Now to understand it all! Not to mention get it working alongside a USB bootloader.

Thanks for the example. The code looks excellent. Way beyond anything I can conceive of.

cheers.

[Squibcakes]

Yep got mine working today too!!! Woo Hoo!!

Golly gosh, loaded Mr E's sample prgram, connected the USB cable and Presto - Windows detected it and it started to work first time!!!

On the demo PCB I added a serial connector so that I can program the 18F4550 via serial ICSP, and also added a couple a RS422/232 line driver receiver so that the PC can communicate via USB to serial devices.

I'm sure I'll have more to add once I've played around with this toy some more.

Cheers
Squib.

See photo attached.