Objective Development Forums

Hi, is it possible to implement host-mode in firmware? Haven't found anything about that in docs. Basically, the idea is to connect USB keyboard to microcontroller. I already bought AT90USB1287 for that which defenetly would allow me to connect keyboard, but after great success with V-USB-based clie...

Hi there, I just managed to run my first V-USB project on Mega48 without crystal, and did small investigation on working OSCCAL range:
Autodetected OSCCAL is 0xF1-0xF2 for both 3.3 and 5v power supply.
Device still works in 0xEF-0xF6 range, so it is not as fragile as I've thought.

Ok, finally device works.
It works fine without zenerz and without usual diodes for both 3.3(kinda expected) and 5v supply on both my PCs.

Full success It appeared that I just didn't programmed fuse to make default RC clock 8Mhz instead of factory's default 1Mhz Autocalibrated value appeared to be 0xF1 - 0xF2, and it works in the range 0xEF-0xF6 (Another topic about that) for both 3,3 and 5v power supply (Yeah, 48V version worked at 12...

Just a heads up: I just validated that my Mega48V works fine on the OSCCAL range 0-255 @3.3v. So the question is does it reach 12.8Mhz at high range of OSCCAL (visually difference between 0 and 255 is about 4x)... I'll try to work on measuring & displaying current clockrate based on RC calibrati...

santacruzbob wrote:I don't think you can generate that clock internally on a chip without a PLL

Wait, but there were reports that it is possible to calibrate RC oscilator for that clock?

I would try it without diodes 1st. Supposedly 80% of USB hosts will tolerate it and the ones that don't will just refuse service to the device, not burn up Thanks for reply. I think I'll just leave placeholder for zener on PCB, and will just work without them until I would get one I'll let you know...

Is that possible to use couple of 1N4148 diodes(3.3/0.7 = 4-5 ones) instead of 3.3/3.6V Zener ones? And sorry for terrible question, can I just feed 5v on a USB as a temporary solution? (I'll have Zeners in about 2 weeks, too slow....) Will it immidiately burn PC's controller (provided that's a spar...

Hi, I am trying to run EasyLogger on Mega48 without crystal. I've changed clock to 12.8Mhz: #define USB_CFG_CLOCK_KHZ (12800) Also, I've changed port I am connecting to (D). For the beginning I've commented all ADC-related stuff to keep things simpler. Unfortunately, it does not work - windows shows...