FDTI Mod For LPC8xx upload.

Added by over 4 years ago

Good to see you back in business. Nice work on modding the FDTI board so that it can put an ARM processor into running the bootloader. I use the bigger LPC chips a lot and am trying to persuade some of my clients to change over from PICs and AVRs to LPC8xx’s, which are cheaper, faster, better. Never understood the wasted CTS input on these boards.

Replies (2)

RE: FDTI Mod For LPC8xx upload. - Added by over 4 years ago

Actually, there may be a small problem, if you remove the series capacitor on DTR, when you open the port with a terminal program the default behaviour of DTR from the FDTI chip is to go active, which is actually 0V. So it will hold the processor in reset and drive you mad as you try to find out why it is not talking to you, even though the download completed successfully :).

Normally the DTR + cap just resets the processor when the port is opened by a terminal, and is used to start theArduino bootloader, which waits a few seconds fo a new download, then just runs the user code.

RE: FDTI Mod For LPC8xx upload. - Added by martynj over 4 years ago

Correct in the general case - hence the cap on the USB BUB.  But in the specific case of the JeeNode family, there is also a series cap on the main PCB (belt and braces to hold up the trousers!).   So shorting out the USB BUB cap meets the ARM requirement and continues to work with the classic JeeNodes.