Unboxing the Freescale FRDM-KL43Z Board

I’m preparing for the next semester at the university starting in September this year. As part of that, I’m currently evaluating the Freescale Kinetis FRDM-KL43Z board:

FRDM-KL43Z Board Unpacked

FRDM-KL43Z Board Unpacked

FRDM-KL25Z, the most popular Freedom Board?

The Freescale FRDM-KL25Z board is used a lot, including in this blog when I first used that board back in September 2012: there are plenty of tutorials available, the board has the best price/performance ratio, and students including myself really love it. Freescale has later on released other FRDM boards with better features, but in my opinion they were simply too expensive and not well supported with examples and tutorials. I have monitored my board distributors on Mouser.com and Farnell/element14, and the number of available boards and the inventory fluktuations let me believe that indeed the FRDM-KL25Z is probably a high runner for them too. The FRDM-KL46Z would have been a good sucessor of the FRDM-KL25Z, but yet again, the price/performance ratio was not matching the KL25Z board: the FRDM-KL46Z was in the >$25 range 😦

Checking recently the price point of the FRDM-KL46Z, I noticed that it was now down to CHF 19, still 50% up to the CHF 12 for a FRDM-KL25Z. But at the same price as the FRDM-KL46Z I saw that there is a FRDM-KL43Z which I had not used yet. So I ordered two boards to explore it.

Package Content

The board comes as the other FRDM boards in a card box with a Quick Reference card, without USB cables and without headers populated:

FRDM-KL43Z Package Content

FRDM-KL43Z Package Content

FRDM-KL43Z Board Top Side

FRDM-KL43Z Board Top Side

FRDM-KL43Z Board Bottom Side

FRDM-KL43Z Board Bottom Side

Freedom Board Comparison

The picture below shows the three boards from left to right: FRDM-KL25Z, FRDM-KL43Z and FRDM-KL46Z:



Device KL25Z128 KL43Z256 KL46Z256
Part MKL25Z128VLK4 MKL43Z256VLH4 MKL46Z256VLL4
Package LQFP, 80 pin LQFP, 64pin LQFP, 100 pin
ARM Cortex-M0+ Cortex-M0+ Cortex-M0+
FLASH 128 Kbyte 256 Kbyte 256 Kbyte
SRAM 16 Kbyte 32 Kbyte 32 Kbyte
Max Speed 48 MHz 48 MHz 48 MHz
Push Button no 2 2
Touch Slider yes yes yes
LED RGB Green, Red Green, Red
Accelerometer MMA8451Q MMA8451Q MMA8451Q
Magnetometer no MAG3110 MAG3110
Light Sensor no Analog, ALS-PT19-315C/L177/TR8 Analog, ALS-PT19-315C/L177/TR8
Segment LCD no 7-Segment, 4 digits 7-Segment, 4 digits
OpenSDA P&E, V1 P&E, V1 P&E, V1
USB yes, needs crystal yes, crystal-less yes, needs crystal
ROM Bootloader no yes no
Processor Expert full: LDD and SDK partical: SDK only full: LDD and SDK
Price (CHF) 12 19 19

So the FRDM-KL43Z is very similar to the FRDM-KL46Z, but around 50% more expensive than the FRDM-KL25Z.

💡 Check your local distributor prices, as I have found pricing Freedom boards very inconsistent, depending on distributor or local distributor web store!

Compared to the FRDM-KL25Z the KL43Z has more FLASH, more RAM, Magnetometer, 7-Segment LCD, push buttons and an ambient light sensor, and has a smaller package than the KL25Z (80 pins) and KL46Z (100 pins). Because of the less pins on the package, not all Arduino header pins on the side are connected.

An interesting feature I need to explore is the ROM bootloader present in the KL43Z. On the downside, the KL43Z is not fully supported any more with Processor Expert, making writing and porting applications to the KL43Z much harder or even impossible :-(.

Freescale Kinetis Design Studio Support

The FRDM-KL43Z is listed in Kinetis Design Studio, with Kinetis SDK v1.2 installed:

FRDM-KL43Z Board in Kinetis Design Studio

FRDM-KL43Z Board in Kinetis Design Studio

Processor Expert is only supported in combination with the Kinetis SDK:

SDK and Processor Expert Support

SDK and Processor Expert Support

So there is no LDD (Logical Device Drivers) support available for the KL43Z. That means that all the existing tutorials using Processor Expert for all the other boards will not work any more, projects cannot be easily ported and I have to start pretty much from scratch.


The FRDM-KL43Z is a new board, very comparable with the FRDM-KL46Z. On the plus side it comes with a ROM bootloader and crystal-less USB operation. On the downside I would have to rewrite all my existing applications for that new board. It is supported with Kinetis Design Studio (Segger and J-Link). So from that perspective the FRDM-KL46Z is better enabled than the KL43Z. If the price of the FRDM-KL43Z would get closer to the FRDM-KL25Z one, then the FRDM-KL43Z could be the next Freescale Freedom High-Runner board. The bit (potential) plus of the KL43Z in my view is the ROM bootloader, so I would like to explore this in one of my future articles.

Happy Evaluating 🙂


10 thoughts on “Unboxing the Freescale FRDM-KL43Z Board

  1. Hello Eric

    Why not also check out the uTasker FRDM-KL43Z support – http://www.utasker.com/kinetis/FRDM-KL43Z.html
    It allows you to simulate the SLCD: http://www.utasker.com/docs/uTasker/uTasker_SLCD.pdf
    (There is a video showing it on the older K40: https://www.youtube.com/watch?v=nm2DmZv1rj8) and can be build with KDS, CW, IAR, Keil, Rowley Crossworks, Greenhills, Atollic, CooCox.
    Including KBOOT serial and USB, USB-MSD, SD card, Developer’s serial loader.
    In the link there is also nRF24L01+ operation with it.

    The only thing I find a nuisance with the KL43 is that the I2C is now double-buffered but seems to have a nasty new bug as master because if the debugger is stopped it will continuously send clocks (forever)!




    • Hi Mark,
      thanks for the links. I had looked into the uTasker project already (thanks for your great work there!). And thanks for the hint about that I2C silicon bug: I need to keep that one in mind, as it could be really nasty during development :-(.


  2. Hello, a newbie here 🙂
    I have a question regarding: “there is no LDD (Logical Device Drivers) support available for the KL43Z”
    What limitations does it put? So far I made hello world and a simple UART program and did not encounter any difficulties. What will be hard? Can you give an example?
    I just want to say now I want to connect my SSD1306 LCD to KL43Z and I hope I won’t have any problems 🙂


    • It means that you cannot use Processor Expert without the Kinetis SDK. And it means that you cannot use non-SDK functionality or components with the KL43Z. KL43Z is Kinetis SDK (plus Processor Expert).
      Or in other words: if you have a project say created for the Kintis K60 or KL25Z done in the past, and now you want to move that project to the KL43Z, it means that you have pretty much to restart that project from the beginning: you cannot re-use the existing concept and components.
      But as (probably) in your case, if you are starting from a blank sheet, of course you won’t see a problem (I hope).


  3. Pingback: Using the Freescale Freedom (FRDM-KL43Z) to Debug other Boards | MCU on Eclipse

  4. Pingback: Playing Tetris with a FRDM-KL43Z Board | MCU on Eclipse

  5. Hi all
    I have a problem trying to set up my FRFM-KL43Z Board for a first time, I installed Kinetis Design StudioVersion: 3.2.0 but FRFM-KL43Z is not in the board list, To solve it I’ve download SDK_1.3_FRDM-KL43Z and SDK_2.0_FRDM-KL43Z but I don’t know how to install it. Wen I try to intall the package using “Install new software” on KSD help menu, the system returns an error “SDK_2.0_FRDM-KL43Z”

    Thanks for your help.


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