u. Can I use J chips on an unmodified K8055 board? Can I possibly use full speed USB with an unmodified K8055 board?

QUESTION

"You cannot possibly use any of the J chips on an unmodified K8055 board. It supplies 5V to Vdd and the J chips are designed for 3.3V. You would damage the chip. The PIC18F2550 and PIC18F25K50 can run on both, 3.3V and 5V. You also cannot possibly use full speed USB with an unmodified K8055 board. R39 forces the USB connection to be low speed. It must be removed. Your claim "No soldering, no risk of damaging the expensive Velleman PCB" therefore can only apply to the K8055N."

ANSWER:

If you want to use a PIC18F24J50 or a PIC18F26J50 microcontroller on a K8055 board, you have to use a simple adapter from this website, because the "J chips" are not entirely pin compatible with PIC16C745. The adapter works with USB 2.0 full speed, so you even make your K8055 board to communicate with your PC much faster....

But you still do not need to modify your K8055 or K8055N experiment board to use my HW (i.e. MX32FX250F128B adapters)” and my FW. No soldering on the original Velleman PCB.. You just make the adapter and you plug it in… That’s it.. If you want to remove the adapter, you take it out and you replace it with the original chip…

The fact is also that if you program a microcontroller in place, it is 2 or 3 times faster than if you have to pull out the chip every time you need to reprogram it. K8055 board lacks this connector, but my PIC32MX250F128B adapter has it. It is also easy to add such a connector to the PIC18F2xJ50 to K8055 adapter.... No wonder, why K8055N boards were designed with SK9 connectors. The connectors perfectly fit to PICkit3 though Velleman has never officially described their real purpose. But it is clear to me that if you want to program K8055N board, you can do it directly via SK9 connector with PICkit2 or PICkit3. You need no bootloader or programming header… You can also do it without ever removing the microcontroller from the PCB. Debugging in place is also a big plus.. With PICkit3 you can even debug in real time... It’s at least 10 times faster than classical programming..., because you can instantly see what is not working in your code...