Getting Bluetooth Working with JY-MCU BT_BOARD V1.06

For my embedded course at the University of Lucerne of Applied Sciences and Arts I needed more Bluetooth modules for the Zumo/Sumo robots. I run out of stock as the modules are getting popular and are used in many student projects. So I ordered a handful more from DX/DealExtreme of the same HC-06 type/part number I already ordered a while back. I expected that they will work as the modules I had ordered from DX half a year ago. Was that naïve? Probably. Because they did *not* work, and caused me to reverse engineer the modules and to apply a hardware fix to get them working….

Set of JY-MCU Bluetooth Modules

Set of JY-MCU Bluetooth Modules

 

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Serial Terminal View with Eclipse Kepler

Nearly all of my projects have built-in command line support: using a serial connection, I can send commands or inspect the system status. For this I have my command line Shell which works over serial-to-Bluetooth, serial-to-USB, USB CDC or with a physical serial (COM) port. But what I need on the host system is a Terminal program: I can use either an external program. There are many ones available (Tera TermPuTTY, …) where Termite is my favorite one. But it is possible to extend Eclipse so it has its own Terminal view too :-).

Eclipse Terminal View

Eclipse Terminal View

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RNet Stack as Component, nRF24L01+ with Software SPI

The great thing with Processor Expert is: it writes the code for me :-). I’m using now the RNet wireless stack in more than 10 different projects, and keeping the projects up-to-date with the RNet stack sources in a traditional way gets harder and harder: I  need to make sure the paths are pointing to the right place, and if I pass the project to somebody else, I have to make sure all the sources are packaged with that project. Processor Expert makes things simpler: it can generate the source files into my project, and I can easily configure it.

So instead to copy and support files by hand, I decided to package the RNet stack files into a Processor Expert component: all still normal C files, but easier to configure and distribute.

RNet Component

RNet Component

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FreeRTOS, malloc() and SP check with GNU Tools

FreeRTOS has many memory allocation options (see Memory Management) with four ‘schemes’. One of it is the a simple wrapper over the library malloc() and free() routines. I admit, I have not used them, as usually I avoid to include such kind of libraries, as they have their own problems. Anyway, a discussion in the FreeRTOS forum raised my interest: obviously some malloc() implementation (as in the EWL library of CodeWarrior) are making a safety check against the current stack pointer.

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Starting Point for Kinetis Low Power LLS Mode

In “IoT: FreeRTOS Down to the Micro Amps” I’m using an application with FreeRTOS to get down in micro amps low power mode. Well, nearly all or my applications are using FreeRTOS because it makes the application scalable and extensible. Still, for anyone not used to an RTOS, that might be a hard start. So here we go: how to get into the Kinetis Low Power LLS Mode *without* an RTOS.

Power Measurement

Power Measurement

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Variable Debugging with Eclipse Kepler

The current Eclipse Kepler version comes with changes for debugging variables. I have students coming from the earlier Eclipse versions, so here are a few tips for dealing with variables in Eclipse Kepler.

Variables View in Eclipse

Variables View in Eclipse

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Sharing Debug Configuration with Eclipse

Maybe you had this problem too: you shared a project with somebody, only to realize that your carefully crafted debug configuration was not shared?

Eclipse has the concept to store settings in the ‘framework’. The ‘framework’ is the Eclipse internal data, basically what is inside the .metadata folder of the workspace.

metadata folder in workspace

metadata folder in workspace

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