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?
The Pololu Zumo chassis is nearly perfect for my needs: it is small and compact, and neatly works with the FRDM-KL25Z board. I’m able to use it for line following or maze solving. But it lacks a position (quadrature) encoder on the wheels which is either very useful or even required for the lecture assignments for my next class. The Pololu Zumo chassis mainly has been designed for Robot-Sumo competitions, where such quadrature sensors are not really needed. Pololu offers optical quadrature sensors for their 42×19 mm wheel which I used in this project. So why not adding these sensors to the Zumo chassis?
FRDM-Robot with Quadrature Sensors Mounted
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
Beside of USBDM, there is another Open Source implementation of a debug interface for the Freedom Board OpenSDA: CMSIS-DAP.
CMSIS-DAP (Source: http://nimblemachines.com/cmsis-dap/)
CMSIS-DAP stands for ‘Cortex Microcontroller Software Interface Standard – Debug Access Port’) has been published by ARM Inc. With this, there is an open source alternative to proprietary implementation (e.g. P&E OpenSDA or Segger OpenSDA).
Beside of the ARM MDK IDE, CMSIS-DAP is supported by Coocox and IAR. And IAR is what I’m using in this post.
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
MCU on Eclipse 