I'd like to use Flash Magic to load programs onto my LPCXpresso1769 development board (https://www.embeddedartists.com/wp-content/uploads/2018/06/LPCXpresso1769_CD_revD.pdf), via ISP.

I purchased a USB to Serial data converter - TTLl-232R-3v3(https://www.ftdichip.com/Support/Documents/DataSheets/Cables/DS_TTL-232R_CABLES.pdf), and wired it up to the board as follows:

1) GND (FTDI Black) goes to J2-1.

2) TXD (FTDI Orange) goes to J2-22.

3) RXD (FTDI Yellow) goes to J2-21.

The board is powered via the USB debugger probe

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I enter ISP mode in the typical way, although it appears that the RESET button on the board is actually the ISP button, and vice versa (can anyone confirm this?), so I tried both combinations to make sure I was entering ISP mode.

In Flash Magic, I tried all available COM ports, and a range of baud rates, with the clock set to 12Mhz. I tried to establish a connection by using Read Signature, and on all occasions, a "Failed to transmit or receive", or, "Auto-baud" error was displayed. Is there anything glaringly obvious I'm doing wrong?


1 Answer 1


I've finally sorted the problem.

It appears that the board needs to be powered externally (i.e. not via the debug probe/usb)

  • \$\begingroup\$ just a guess .... maybe you can use the USB cable to power the device .... you just cannot have data lines in the USB cable \$\endgroup\$
    – jsotola
    Apr 19, 2019 at 20:29
  • \$\begingroup\$ note: you can accept your own answer \$\endgroup\$
    – jsotola
    Apr 19, 2019 at 20:30

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