There was one part missing to complete the software support for my Arduino DataLogger Shield on top of my FRDM-KL25Z Freedom board: support for the Maxim DS1307 RTC (Real Time Clock).
DS1307 on the Adafruit Data Logger Shield (Source: http://www.ladyada.net/make/logshield/design.html)
Things got delayed a bit, as I first needed to get the I2C infrastructure up and running (see this post). But finally, I have things working :-). I proudly present: RTC_Maxim!
The Kinetis ARM Cortex-M4(F) is a wonderful machine: a 32bit architecture, plenty of FLASH and RAM, an ideal play field. I love the Kinetis Tower boards, and even more the Freedom board which has an ARM Cortex-M0+ on it. I have a lot of projects on S08, S12 and ColdFire at the university, and they are all using a lot of Processor Expert components. Processor Expert is such a great productivity tool: having software in components allows easy software re-use. With Processor Expert abstracting from the hardware, I can easily port my applications to new boards and processors. Well, until Processor Expert changed for Kinetis :-(.
Typically a Processor Expert component creates two files: a header file and a source file. That’s fine for normal drivers. But this does not work well for more complicated things like an RTOS or communication stacks: these are built from a whole set of source files. So how can I generate multiple files with a Processor Expert Component?
Writing Processor Expert components is not always completely independent of the compiler and underlying microcontroller. In many cases I need to know the compiler for which the source code is generated. Or I need to know on which CPU architecture the code shall run. For this I need to know the compiler and the CPU family.
In my class at the university I’m using a microcontroller attached to a DC motor from Maxon. The job of the microcontroller is to implement (among other things) a PID controller for the motor speed (or position). In the lab we implement the PID and all the related parts of the control loop without Processor Expert. But it easily can be done as well with Processor Expert components, as described here.
Ah, a lot of work went into a new Processor Expert component, and finally it shows up in the component library:
default user icon
Oh, wait: *that* icon does not look nice enough for that amount of work behind the component?
In my previous post I mentioned the Drivers\Common folder which has ‘include’ files. These files are maintained automatically by the Component Wizard. But what is the purpose of these files?
The Common Folder has *.inc files which are included in the driver as ‘function’ header. The .inc file contains documentation about the function and parameters for that function.
What I describe here is an overview about the different locations, folder and files you will see if you are importing or developing a Processor Expert User component. I’m showing below example screenshot for the FreeRTOS component, as this is probably the most complex one I ever have created.
OK, I think this topic is a very special one, and probably not of interest of many folks out there. Or how many want to create a Processor Expert Plugin for an RTOS? Well, I did this. And I think that topic might be very controversial too, especially for all the RTOS vendors out there :-). The thoughts expressed here about creating Processor Expert components do not only apply for an RTOS, but as well for any other ‘complex’ software or stack. So if you are interested about the ‘behind the scenes’ of creating Processor Expert components, especially in the context of an RTOS, then read on ;-).
The Freescale ColdFire V2 (MCF52259) is a great communication device: an embedded Processor like a Swiss Army Knife: Great peripherals, USB and Ethernet interface, a lot of flash application space and up to 64 KByte of RAM. I’m using that core in many projects, and there is great community support for it with boards and software. Unfortunately Freescale somehow provides Processor Expert support only half way for it. Support for the I2C bus is missing :-(.
MCU on Eclipse 