I’m working with a student on building a small autonomous robot platform, based on the FRDM-KL25Z board. We integrated new software modules, compiled and linked, and then downloaded the application to the board. While debugging and stepping through the application startup, I had this:
The Debugger has lost communication on connection
Outsch! That’s not good. Even worse, trying to connect again to the board failed 
. What happened?
About a year ago I started to use the FRDM-KL25Z board (RevD). Finally, I had it in my hands: the RevE board from Mouser 
Using the RevD board, I faced several problems:
The good news: all of them have been improved in the FRDM-KL25Z RevE Schematics:
FRDM-KL25Z RevE Board
You have decided: More than 52% voted in Part 1 that the next topic should be Timed Servo Moves. So here we go .
This is about how to move the servos over time, instead of moving it to the given position as fast as possible. I’m using a linear approach here: moving the servos linearly over time.
Moving Servo Motors
This post starts a small (or larger?) series of tutorials using the Arduino Motor/Stepper/Servo Shield with the FRDM-KL25Z board. That motor shield is probably one of the most versatile on the market, and features 2 servo and 4 motor connectors for DC or stepper motors. That makes it a great shield for any robotic project .
Arduino Motor Stepper Servo Shield with FRDM-KL25Z
Character LCD’s (like 2 lines with 16 characters each) as in this post are easy to use. Much easier to use compared to full graphical LCDs.
The ones I’m using have either 1 or 2 lines, but I saw that there are 4 line displays too. So far my LCD component only supports one or two lines.
4 Line LCD (Source: Ezequiel Bazotti)
The FRDM-KL25Z tracked robot from my earlier post has gone trough several upgrades:
Tracked Robot with Ultrasonic Sensor
Looks like there is some movement on the ‘OpenSDA Front’: After CodeRed has released their RedProbe OpenSDA firmware, now Segger has released an OpenSDA firmware.
With this, I get a low-cost debugging solution similar to the well-known J-Link run control devices. The OpenSDA Segger Firmware is something like a J-Link-lite.
FRDM-KL25Z with Segger OpenSDA Debug Firmware
My other robots based on the FRDM-KL25Z use Bluetooth as connectivity. This one is using a Freescale IEEE802.15.4/ZigBee/SMAC module:
Robot with SRB MC13213 Board as Remote Controller
With my Pololu line following robot I had strange problems with the sensor array: the sensor values were very unreliable. Until I have found the problem: Instead of the expected 3.3V, my FRDM-KL25Z RevD board provided 2.8V instead 3.3V on the P3V3 Arduino header pin:
Measured 2.8V on P3V3
And that voltage even was lower the more current I needed . Luckily there is an easy hardware fix for this.
As with any software drivers: they are never perfect. The same applies to the Processor Expert components delivered in CodeWarrior for MCU10 or the DriverSuite too. That’s why I have created many more components which are available on GitHub here. All these components are using other components to reach the hardware. But what if a functionality is not exposed through the low-level component? Or what if I want direct access to the hardware? Up to now I had to choose either the Processor Expert way, or to do it in the ‘traditional’ way using an SDK like CMSIS or vendor supplied header files.
With MCU10.4, I noticed that there is another way: PDD (Physical Device Driver).
PDD in the Components View
