It is possible to program firmware into the VNC1L using a legacy PC COM port, provided that the COM port to be used is capable of at least 115200 Baud. This is required because the VNC1L bootloader defaults to 115200 Baud. The Baud rate may be changed by issuing a Set Data Variables command to the VNC1L after establishing communication at 115200 Baud.
Programming the VNC1L device using a legacy COM port requires the use of an RS232 level converter on the UART of the VNC1L to convert between the RS232 signal level and the VNC1L 3.3V level (5V safe). In addition, a jumper has to be fitted to the PROG# pin of the VNC1L to allow for switching between program mode and run mode. Note that for the bootloader to be active the jumper must be fitted before powering the VNC1L. If the jumper is not fitted, the VNC1L will power up in run mode with the bootloader inactive.
A sample block diagram of the hardware requirements for programming from a legacy COM port is shown below:
At present, programming from a legacy COM port will require software development to create a Flash programming application.