Sometimes it takes a very long time to realize a project. Adding the Arduino Ethernet Shield R3 to one of my Freescale FRDM boards is one of it: it took me a year until I have found a few days to work on using the Ethernet Shield with my FRDM-KL25Z.
FRDM-KL25Z with Ethernet Shield
I have not everything in place yet, so I decided to publish things in parts. So this is about part one: using the Micro SD Card on the Shield.
Character based LCD displays are great: they are inexpensive, and it is rather simple to use them compared to graphical displays. Yes, they only can display text and custom symbols, but this is usually what I need. And pretty much all character displays are using the Hitachi HD44780 protocol, so it is a de-facto industry standard.
HD44780 compatible Dual Line Character Display
These displays have one big disadvantage: they need to be compatible with the original Hitachi interface and protocol. First display were mostly one line only, and had only few characters, typically up to 16. The protocol worked either with one or two lines on the display. Today’s display have usually two lines, with 16 characters. But what if I need more?
4-Line LCD (Source: Daniela Solorzano)
I probably would have missed the fact that Freescale has released a new Freedom board, if I would not have visited my local distributor site to order a replacement for one of my first FRDM-KL25Z boards. So surprise, surprise: there is a new Freedom board: the FRDM-KL26Z!
FRDM-KL26Z Board
So instead ordering again a FRDM-KL25Z, I decided to order that new FRDM-KL26Z instead. And it arrived right before Christmas, and now I had time to check it out. Nope, I did *not* use it as a blinking gadget on a Christmas tree, even if that would have been a nice idea ;-).
I admit: I have used ARM Cortex cores a lot in the recent months. Yes, I think with the ‘ARM domination of the world’ over time the ARM core will blast away probably all other cores, except for niche players? Still, there are reasons to use non-ARM cores, and even if it is just that I have a board at hand :-).
DEMOQE with MC9S08QE128 and MC13201 Transceiver Card
Time to write an update about the RNet Wireless Stack. The stack has been successfully used for the Sumo Robots as wireless controller. In the last week, there has been a lot smaller and larger extensions for it. And because the nRF24L01+ modules are so inexpensive, I bunkered more than 50, with 20 still left to be deployed:
nRF24L01+ Transceiver Modules
It was Friday the 13th, and it was Sumo Battle Day :-). After 3 months of tinkering, hacking and creatively improving the Mini Sumo Bots, finally the the course tournament took place.
With using a different room, every team had a chance to warm up and recalibrate the sensors for the new environment.
Getting ready for the battles
The time was used to apply last-minute changes and improvements too, plus to record the last Robo Portraits.
I have one rule I try to follow every day: my code shall be warning free. Writing software for multiple compilers gets challenging with this rule, but it avoids the ‘not seeing the forest because of the trees’ problem. This rule extends to writing Processor Expert components with CDE (Component Development Environment). What I have missed (and not used) is a useful option to enable debug output:
Enable Processor Expert Components Debug Verbose Mode
The good thing with the internet is: it allows engineers to collaborate. And here is an example: Marc is a reader of this blog had a problem with the I2C hardware of a Freescale Kinetis ARM microcontroller. In his case, the I2C bus could be stuck, and there seems no way to reset it with the I2C hardware on the microcontroller. So a solution would be to reset it with software instead.
Bit Banging Software I2C Driver
I was searching the internet for an open source network stack for my nRF24L01+ transceivers. But these stacks were either too heavy or had a restrictive or not really non-open source license behind it. I was very reluctant to start with something I think already should exist. Two weeks ago I decided that I just do it from scratch, and here I am: I have the basics working 🙂
Two FRDM-KL25Z with nRF24L01+ Transceivers
In case you are desperately looking a component in the components library view, but somehow it does not show up? For example I know there is component ‘InterruptVector’, but it is not present in the Components library view?
Where is the InterruptVector Component
MCU on Eclipse 