5 years, 5 months ago.

FDRM-KL05Z disconnects


Since I downloaded the mbed firmware to the FRDM-KL05Z board it disconnects and reconnects about every 30 seconds making it hard to work with . Does anyone know what is happening and how to make the board stay connected?


Question relating to:

The FRDM-KL05Z is an ultra-low-cost development platform enabled by the Kinetis L Series KL0x MCU family built on the ARM® Cortex™-M0+ processor. Features include easy access to MCU I/O, battery-ready, …

2 Answers

5 years, 5 months ago.

Hi Roland

The NXP Freedom boards, like the FRDM-KL05Z, include a multi-mode debug interface called OpenSDA. Each boards embeds a Kinetis K20 MCU, which flash has been preprogrammed with a Bootloader on the top of which users can easily load from the file explorer their prefered Application (sda or bin files) for MSD flash-programming, USB to Serial and Debug modes, the mbed solution being one of those. FRDM-KL and FRDM-KE boards feature a PEmicro proprietary Bootloader (also called OpenSDA v1). The FRDM-KL05Z has been launched early 2013, when Windows 10 didn't exist, so the version of its Bootloader needs probably to be updated.

The good news is that the operation is very easy:)

1. To garanty the success of the operation, ideally you should use a Windows 7 computer, but Windows 8 computer should be OK 2. Just visit the PEmicro website section dedicated to OpenSDA (www.pemicro.com/opensda) and download the latest OpenSDA Fimware Apps package. 3. Extract the zip file OpenSDA_Bootloader_Update_App_v111_2013_12_11.zip and extract again the file BOOTUPDATEAPP_Pemicro_v111.SDA on your computer hard-drive. 4. Keep Reset button pressed while connecting the USB cable, to start the board in Bootloader mode and release it after 2s. 5. Drag n drop the file "BOOTUPDATEAPP_Pemicro_v111.SDA" into the Bootloader drive from your file explorer and wait the download to complete. 5. When Green LED stop blinking, unplug and re-plug the USB cable from the FRDM-KL05Z OpenSDA USB port, your board should be now programmed with the latest PEmicro Bootloader version v1.11, which according to the release notes (included in the zip package), add support to MAC, Linux and Windows 8.1 and later. 6. The latest mbed Application for the FRDM-KL05Z is available on the developper.mbed website (https://developer.mbed.org/handbook/Firmware-FRDM-KL05Z), to program it, simply restart your board in Bootloader mode and drag n drop the file "20140530_k20dx128_kl05z_if_opensda.s19" into the Bootloader drive. When Download completed (Green LED stop blinking) restart your board and you should be fine.

For more informations about the OpenSDA interface please visit the NXP website: www.nxp.com/opensda Here you will find all the applications compatible with your board (PEmicroDebug_MSD, CMSIS-DAP_mbed, JLink), just select it in the list.

Please let us know your feedback if those steps resolved your computer issues? Thanks

Accepted Answer

Tbh maybe it helps, but I don't think it should matter, since he already did manage to flash the mbed firmware on it, so the SDA bootloader shouldn't matter.

Edit: Also it will take some getting used to, to see Freescale being called NXP now :).

posted by Erik - 10 Jan 2016


After some hazzle and the work of digging out an old XP-computer frolm the closet (the only win7 computer in this house is my daughters and that was occupied) I have finally got everything up and running. I have written a few simple test programs and everything seems stable.

Than you for your help.

Regards Roland

posted by Roland Larsson 10 Jan 2016
5 years, 5 months ago.

Does it also happen with another PC? And/Or another USB cable?

No. On my laptop it works fine but on my stationary it keeps disconnecting. Well, I can work on my laptop if I cant find a cure for my stationary.

I'm running windows 10 on the machine where the board disconnects and windows 8.1 on the one where it works.

posted by Roland Larsson 09 Jan 2016

I am not aware of specific issues with W10 which don't occur on W8.1. Trying another USB cable, if you hadn't done so yet, can't hurt, cables have been known to be possible problems. But outside of that I have very little advice, haven't heard this problem before. You can try another USB port also (not the one right next to the current one you use, but for example a rear-USB port instead of front). Or if you have one lying around anyway, a USB hub in between.

posted by Erik - 09 Jan 2016