Using the FRDM-KL25Z as USB Keyboard

I miss my old DELL laptop. Ok, the new one I received from IT services is not bad. It is faster and has a better screen. But I’m not really happy with the new keyboard. With the previous keyboard I was able to do a ‘PrtnScrn’ with a single key press. With the new one I need to press Fn + PrntScrn. And this is impossible to do with one hand:

Impossible to reach Prnt Scrn

Impossible to reach Fn+Prnt Scrn with one hand!

Yes, I have two hands ;-). But many times I need to do ‘print screen’ while having my other hand on the mouse :-(.What else can I do?

Continue reading

Advertisements

Using Keil µVision 4 (ARM-MDK) with Processor Expert Driver Suite

❗ This article has been written for the version 4 of µVision. There is an update for version 5 of µVision here: “Using Keil μVision 5 with Processor Expert

The good thing with using ARM microcontroller is: there are plenty of tool choices. Even myself, I’m using multiple different tool chains. And while I’m heavily using Eclipse, there are non-Eclipse tool chains which have their advantages too.

The cool thing with CodeWarrior is that beside of Eclipse based, it comes with Processor Expert integrated. And I’m using Processor Expert a lot in my projects. But using Processor Expert does not mean I’m limited to CodeWarrior or Eclipse. So I can use CodeRed or IAR as tool chain with it. And this post is about using Processor Expert with the µVision tool chain from Keil/ARM.

Keil uVision Splash Screen

Keil uVision Splash Screen

Continue reading

5V Generation from V_IN on the Freedom Board RevE

The Freescale Freedom boards like the FRDM-KL25Z feature an Arduino header so I can stack shields on it. Unfortunately, the Freedom board does not generate 5V if not connected to the USB cable. This makes it not possible to be used with many shields like the Adafruit Motor Shield: such shields expect that the Arduino board is providing 5V through the Arduino header (Pin 10 on J9 on the FRDM-KL25Z). So I had to do hardware changes to generate that 5V if I used my board disconnected from USB, e.g. running from batteries through V_IN (pin16 (P5-9V_IN) on the FRDM-KL25Z.

J22 with Capacitors on FRDM-KL25Z RevE

J22 with Capacitors on FRDM-KL25Z RevE

The good news is that the Rev.E of the Freedom FRDM-KL25Z board has now a header J22 to make things easier:

Continue reading

Using the HC-06 Bluetooth Module

After my first post using a Bluetooth module, things have evolved a bit. The challenge with these Bluetooth modules is: they look the same, but having different firmware. I did not fully realize that until I have ordered another bluetooth module from dx.com:

DX.com Bluetooth Module (HC-06)

DX.com Bluetooth Module (HC-06)

That module comes already on a carrier, so I assumed I can use the same driver as for my other module. I was wrong :-(.

Continue reading

Tutorial: Arduino Motor/Stepper/Servo Shield – Part 3: 74HCT595 Shift Register

For many projects, I have one common problem: I run out of I/O pins on my microcontroller :-(. Luckily, I’m not alone, and the industry has created solutions for this kind of problems. One is to use a shift register as the 74HCT595/SN74HC595 which gives me 8 extra output pins. All what I need to spend are are 3 GPIO pins. Not a bad deal: I spend 3 pins and I get 8 (or multiple of it) on return :-).

So why do I say this for this Arduino Motor/Stepper/Servo Shield tutorial? I have asked in this earlier post with a poll for the next topic (relais, motor or command line interface). Right now votes are mostly for relay. But before I can do relay (or DC motor), I need to first cover the 74HCT559. So here we go to have you ready for the next tutorial 🙂

Arduino Motor Shield

Arduino Motor Shield with 74HC595

Continue reading

Bricking and Recovering FRDM-KL25Z Boards: Reset, SWD Clock and Low Power

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

The Debugger has lost communication on connection

Outsch! That’s not good. Even worse, trying to connect again to the board failed :-(. What happened?

Continue reading

Adding Quadrature Encoder to the Zumo Chassis

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

FRDM-Robot with Quadrature Sensors Mounted

Continue reading

Eclipse Problems View: Only Show Problems for Project

Having many projects open the same time, and working on them in parallel is a challenge. Ok, the human brain is not built for multitasking, but I still try ;-). What I typically I end up in my Eclipse Problems View to have entries from multiple projects mixed up:

Problems View with Entries for multiple Projects

Problems View with Entries for multiple Projects

How to show it that I can fix the problems for ony project only, and not showing all problems from all projects?

Continue reading

Traps and Pitfalls: No Hex/Bin/S19 File Created with GNU?

I stumbled now twice over a problem, and only after a lot of head scratching (you should see my head now 😉 ) I have found the cause (and solution) for it. In the hope that I can save the readers of this blog some time, here is what happened.

I described in earlier posts how to enable GNU build tools to generate hex/bin/S19 files, or to write the code size to the console view. That works fine for me. But then I received a project were obviously this does not work: even with the project settings configured properly, there is no S19 file, and no code size printed. What’s wrong?

Additional Tools in ARM GNU Eclipse Panel

Additional Tools in ARM GNU Eclipse Panel

Continue reading

FRDM-KL25Z RevE Board arrived

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:

  1. 3.3V supply voltage drop because of low-cost diode D1 (see this post)
  2. Hard to use USB host mode, as no 5V supplied to the USB bus (see this post)
  3. No 5V generated from V_IN (see this post)

The good news: all of them have been improved 🙂 in the FRDM-KL25Z RevE Schematics:

FRDM-KL25Z RevE Board

FRDM-KL25Z RevE Board

Continue reading

Tutorial: Arduino Motor/Stepper/Servo Shield – Part 2: Timed Servo Moves

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

Moving Servo Motors

Continue reading

Julier Formula Student Electrical Race Car as Television Star

Yesterday the local television station Tele 1 collected film material for a report about the “Julier” Formula Student team. The team did run more tests on the Alpnach air field, and this time the weather was much better compared to the last weekend. With the risk to get sun burned 😉

Until Tele 1 publishes the material, I have here pictures from the scene, the team and the car.

Camera, and Action

Camera, and Action

Continue reading

Julier 4WD Test Drive in Alpnach

While weather is bad and Switzerland suffers from record high rain water levels, the Formula Student “julier” team was testing their race car this week-end after the rollout. This time to test the 4WD with more torque. Plus water-resistance ;-). So here are impressions, pictures and a video from this week-end:

Julier Formula Student Race Car

Julier Formula Student Race Car

Continue reading