e. How many K8055 and K8055N boards can I connect to a PC?

USB 2.0 standard requires a compatible USB controller to support up to 127 devices. But the number of USB connectors in your computer lowers you down to earth. The original Velleman K8055D.DLL only allows you to connect 4 boards.

LIB_PCUSBProjects v6.3.NET4(x64).dll allows you to connect four times as much boards (up to 16). Single threaded SVLIB_PIC18F24J50 v2.7st.dll has no limit on the number of connected boards. The only limit is your PC hadrware (inbuilt USB controllers). Though there are two address jumpers (SK5 and SK6) on a K8055-1 (with a PIC18F2550, or a PIC18F2xJ50 adapter) or a K8055N-2 board, but PC USB Projects firmwares and DLL libraries do not use them. Each microcontroller must therefore be programmed with a unique VID and PID comtination. The default VID/PID combination for PIC18 firmwares is VID = 4D8 (hex) / PID = F001 (hex), and for PIC32 firmwares is VID = 4D8 (hex) / PID = D001 (hex).

PIC Programmer v2.9.9 application enables you to select an arbitrary VID / PID combination for a PIC18 microcontroller. VID and PID may each be selected the range of 0-65535 (0 (hex) to FFFF (hex)). There is also a setup utility for PIC32MX250F128B microcontroller adapters for K8055-1 and K8055N-2 boards. The utility may change the VID / PID combination even without reprogramming the whole microcontroller.

The K8055N multithreading examples (Multithreading example (64-bit) based on SVLIB_PIC18F24J50 v2.8.NET4(x64).zip

and Multithreading example (64-bit) based on SVLIB_PIC32MX2X0 v1.1.NET4(x64).zip) give an impression that the SVLIB_PIC18F24J50 v2.7st.dll supports only a few boards, but this is misleading.You can connect as many as your PC USB controllers support.

ALSO READ:

- PC USB Projects Programming Guide