Error JLINKARM_DLL_ERROR when using Power Profiler

[Ed Kuzemchak]

I am getting an error in the Power Profiler ppk.py when it is starting. The error occurs on the first call to nrfjprog.rtt_read. The error is JLINKARM_DLL_ERROR, which is -102.

(Updated) I wrote a similar small Python program to test pynrfprog and I find that the rtt_is_control_block_found() is always returning False.

I am using the software versions specified in the PPK User Guide:

• Python 2.7.12 (32 bit)
• nRF5x Command Line Tools (which installs Segger JLink 5.12g)
• Python packages as installed by 'python_packages.bat', specifically pynrfjprog 9.0.0

I have programmed the DK with PPK_v1_0_0.hex using flash_pkk.py

Here is the cutdown program that fails to find the rtt control block:

import libs.rtt as rtt
import time
from pynrfjprog import API
JLINK_PRO_V8    = 4000

# Always try to have highest speed
JLINK_SPEED_KHZ = JLINK_PRO_V8

nrfjprog = API.API('NRF52')
nrfjprog.open()

nrfjprog.connect_to_emu_without_snr(jlink_speed_khz=JLINK_SPEED_KHZ)
nrfjprog.sys_reset()
nrfjprog.go()
nrfjprog.rtt_start()
time.sleep(1)
print nrfjprog.dll_version()

# It never exits this while() - just prints 'waiting' continuously
while (not nrfjprog.rtt_is_control_block_found()):
  print 'waiting for control block'
  time.sleep(1)

# This fails with JLINKARM_DLL_ERROR if we let it get here
nrfjprog.rtt_read(0,10000, encoding=None)

[wlgrd]

Oh... Yeh, it only supports the original DK's. But you are saying "running on the dk". The PPK firmware should never run on the DK, but only be flashed to the PPK. If the software finds an RTT session on another board, it may hook onto it, but never give you any valid data. Please make absolutely sure that you are flashing the PPK. With a non-Nordic DK, I assume you have never had contact with the actual PPK.