By Jim Trudeau

As one of the “software guys” in a hardware company I have a pretty easy job representing customer needs. It’s really a no-brainer. Without software, the boards are hard to use. The only way we do well is to give you what you need to get up and running quickly. At the same time, software does not live without hardware. They are two sides of a single solution. The real fun here at Freescale is that we can (and certainly strive to) do a great job putting the two together, thus enabling you better than a pure hardware or pure software company.

The latest entry into our enablement solutions is the Kinetis KwikStik development tool. We announced that on March 31, perhaps because one day later and you might have thought it was an April Fool’s prank. Nothing this good could possibly be available at this price. Yet it is true, the KwikStik has a special introductory price of $29 US (MSRP). That’s right, that price gets you a 32-bit MCU, the Freescale K40, based on the ARM Cortex-M4 core.

For simplicity I’ll repeat a few of the key features of the platform from the press release, to save you some of the reading:

• the SEGGER J-Link debug interface on board
• a very low power capacitive touch capability based on the Freescale touch-sensing module
• a micro SD card slot
• an integrated 306-segment LCD screen

Figure 1: The Kinetis Kwikstik development tool

This is fully compatible with existing Tower systems. You can plug it in and go. In March 2011 I wrote about the Freescale Tower System from Freescale.

A full K40 Tower board, and a complete K40 Tower kit are available separately. The kit includes all the necessary Tower components. The board is not the same, it’s a different form factor, has some different features, and a smaller LCD screen. However, because it is modular you can get other touch-sensitive controllers like a keypad, rotary pad, and so on. The Tower System also gives you access to all kinds of peripherals, from Freescale and 3^rd parties. So read carefully for what works for you.

Figure 2: The K40 Tower board, TWR-K40X256

With a bit of soldering the KwikStik can be turned into the functional equivalent of the stand-alone SEGGER J-Link tool.  The circuit is built into the board and by default it targets the on-board Kinetis K40.  However, with a soldering iron and an inexpensive 9/10-pin connector (plus a ribbon cable) you can turn it into a J-Link with SWD and JTAG interfaces capable of targeting any Kinetis device. Details are in the user manual.

Software

The best part of this, however, is the software. Spoken like a software guy, I know.

There are tools! Freescale’s own CodeWarrior for MCU 10 tools, the Eclipse-based development environment, supports Kinetis MCU. It is complimentary up to 128Kb of code. Other IDEs are available from IAR, Keil, CodeSourcery, and Green Hills.  The CodeWarrior tools include Processor Expert, a knowledge-base-driven software modelling and code generation tool that I wrote about here. You can use this to quickly develop your own custom driver library, suited to precisely your own needs.

We provide a complimentary  MQX operating system, with a scheduler, file system, TCP/IP and USB stacks, and graphics LCD support. It follows the same modular philosophy in software that the Tower System does in hardware. As a result you can fine tune what you build into your application to minimize size and maximize performance. I have mentioned all this enablement software in my previous Tower System article. Reuse!

Since this is a touch-driven development tool, I want to mention in particular the complimentary Touch Sensing Software (TSS) library.

Figure 3: The Touch Sensing Software Suite architecture block diagram

The TSS solution transforms a standard Freescale microcontroller into a proximity capacitive touch sensor controller. The touch sensor controller has an ability to manage multiple touch pad configurations and mechanical keys while maintaining its standard MCU control functionality. The video I linked to at the start of the article discusses some of the flexibility of this library. You can define, for example, the sensitivity thresholds recognized by the touch sensor to wake up the system. In this may you can optimize a system for maximum battery life.

Enablement

The theme I keep talking about is: what does this all mean for you? Well, bottom line, lots of choice, and lots of control over the final cost, either of the evaluation process or an actual production system.

At evaluation time, you can get into the game for $29 US (MSRP). At production time, being able to use the microcontroller as the touch sensor controller means less hardware complexity and fewer parts. Replacing physical switches with capacitive touch might save cost and increase reliability as well.

Finally, as noted in the article on the Tower system, you will not be alone. There is a community built around this amazingly flexible platform, Tower Geeks. Check it out; there is a wealth of knowledge about the Tower System available there, such as schematics and pcb files for projects that others have done.

So keep your eyes open – I predict that this isn’t the last Tower System module that will appear. This is a really innovative approach to reference designs.