Unable to Program: J-link Could not measure total IR len. TDO is constant high.

[Beverly]

Hi All:

The hardware is working perfectly up until I changed some codes in the program and load it on the chip then I am unable to program again. The error message is:

JLink info:

DLL: V4.60a, Firmware: J-Link Lite-Cortex-M V8 Hardware: V8.00 S/N : Feature(s) : GDB

• JLink Info: Could not measure total IR len. TDO is constant high.

Anyone knows how to solve this?

Many Thanks!

[Ole Morten]

Have you looked at some of the other questions about this? You can try either

• nrfjprog --recover from a command line, or
• follow the procedure explained here

[Ole Morten]

To use Master Control Panel, you have to flash the firmware to the dongle, as described in the kit's user guide. Have you done this?

Also, if you're trying to use a Bluetooth example program, you'll have to first load a softdevice. In general, I'd recommend you to work through the Quick Start part of your kit's user guide before doing much else, as that covers both blinky, the Master Emulator firmware and a Bluetooth example app.