LVDS Display controller for microprocessors

October 3rd, 2012 50 comments

We have had a couple of embedded projects for our customers where the requirement were large-screen LVDS displays. By large screen I mean sizes over 7″ and a resolution of 800×480 where the common SSD1963 LCD controller can’t be used as the frame buffer RAM is too small.

LVDS Display Controller V1.0


So now we have decided to make our own similar display controller board but for LVDS displays as they are much more inexpensive and common (used in TVs and PCs).
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Categories: Arduino, ARM, FPGA, Other Microprocessors Tags:

Cortex-M4 and 9DOF for $10

September 14th, 2012 12 comments

Soon to be released is the new STM32 F3 Discovery Kit from ST Microelectronics.

This board features their new STM32F3 microprocessor with a Cortex-M4 core running up to 144MHz together with an FPU and a DSP that was announced back in June.

STM32 F3 Discovery Kit


The exciting news about this upcoming board is the on board features as the board will contain a 3-axis gyroscope (L3GD20) and a 6-axis e-compass consisting of a 3-axis accelerometer and a 3-axis magnetometer (LSM303DLHC).

As the board is supposed to be priced around $10 this will make an extremely low cost AHRS system with plenty of processing power to do the DCM math algorithm together with PID loops and other tasks.

Via ST Microelectronics

Categories: TKJ Electronics Tags:

A practical approach to Kalman filter and how to implement it

September 10th, 2012 337 comments

I have for a long time been interrested in Kalman filers and how they work, I also used a Kalman filter for my Balancing robot, but I never explained how it actually was implemented. Actually I had never taken the time to sit down with a pen and a piece of paper and try to do the math by myself, so I actually did not know how it was implemented.
It turned out to be a good thing, as I actually discovered a mistake in the original code, but I will get back to that later.

I actually wrote about the Kalman filter as my master assignment in high school back in December 2011. But I only used the Kalman filter to calculate the true voltage of a DC signal modulated by known Gaussian white noise. My assignment can be found in the following zip file: http://www.tkjelectronics.dk/uploads/Kalman_SRP.zip. It is in danish, but you can properly use google translate to translate some of it. If you got any specific questions regarding the assignment, then ask in the comments below.

Okay, but back to the subject. As I sad I had never taken the time to sit down and do the math regarding the Kalman filter based on an accelerometer and a gyroscope. It was not as hard as I expected, but I must confess that I still have not studied the deeper theory behind, on why it actually works. But for me, and most people out there, I am more interrested in implementing the filter, than in the deeper theory behind and why the equations works.
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Categories: Guides, TKJ Electronics Tags:

Raspberry Pi GPIO control

September 8th, 2012 13 comments

We have been working with the new Raspberry Pi board for a while but didn’t show it to you guys before now.
Many of you might already have seen and read plenty of videos and articles about it so I thought it would be more appropriate to make a tutorial on how to use the GPIO’s, and especially on how to speed up the GPIO’s.

In this video I walk you thru all the steps from installing the Raspbian image which is based upon Debian. This is by far the most complete and well working image I’ve discovered.
Together with a complete X-window system it also comes with many different developer tools preinstalled such as Python and GCC.

So go watch the video while to set up your own Raspberry Pi for GPIO control.

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Ethernet on STM32F4DISCOVERY using external PHY

August 24th, 2012 193 comments

For you who have read about the STM32F4 Cortex-M4 processor you might know that this processor family includes a 10/100 Ethernet MAC with dedicated DMA that supports supports IEEE 1588v2 hardware, MII/RMII.
This means that the only electronics needed to enable the ethernet capability is an external PHY and the Magjack connector.

On the STM3240G-EVAL evaluation board the DP83848 PHY is used and luckily for us we were able to find a simple breakout board for this chip on eBay.

DP83848 Phy breakout board


To hook up this Phy to the STM32F4DISCOVERY board a slight change in the pins, compared to the connections on the evaluation board, had to be made. Because the STM32F4DISCOVERY board only contains the 100-pin version some of the full MII pins are missing so we have to use the PHY in RMII mode.
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Categories: ARM, Development boards Tags:

Wiimote added to USB Host library

August 21st, 2012 72 comments

This is yet again a new announcement regarding the USB Host library. I just added support for the Wiimote via Bluetooth.
Check out the source code at github: https://github.com/felis/USB_Host_Shield_2.0/blob/master/Wii.cpp and the example sketch as well.
I will work on implementing support for the Nunchuck and Wii Motion Plus extension in the near future.

Update:
The library now also supports the Nunchuck controller and the Motion Plus extensions. The newest version of the library can be found at github.

Another Update:
The library now also work with the new Wiimote where the Motion Plus extension is built-in.
Check out my commit to see what where needed in order to make the new Wiimote work as well – the main difference is that you now have to send the data using the interrupt channel.
To tell if your Wiimote is the new type, it should have a label at the bottom saying “Wii MotionPlus INSIDE”. If you are in doubt take a look at this picture.

Yet another update:
The IR camera inside the Wiimote is now also supported. The the following commit for more information.

A new update once again:
The Wii U Pro Controller is now also supported via Bluetooth.

Categories: Arduino, Bluetooth, TKJ Electronics, USB Tags:

Stellaris Multimedia streaming client

August 9th, 2012 No comments

Some of you might already have seen and read about the Multimedia streaming client project we posted as a video a couple of weeks ago. Though for you who haven’t here comes a description.

The Multimedia Streaming Client in action


Back in May we were kindly given some of MikroElektronika’s latest ARM development tools and decided that we would make a big and time consuming project with it.
As we started planning the project we had no ideas at all but all of a sudden the idea of a Multimedia streaming client struck my head. Why not use the on board VS1053 Audio codec chip for music playback and then use the Ethernet port to add a streaming functionality.
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Categories: TKJ Electronics Tags:

RFCOMM/SPP Library for Arduino

July 30th, 2012 104 comments

This is yet again a new library for Arduino.
But this time it is a speciel one and a library I have though about making for a long time since I wrote the PS3 Bluetooth Library. It is the RFCOMM/SPP library, in short it is a virtual serial port via Bluetooth, which means you can now communicate with your Arduino via Bluetooth using a normal terminal application on your computer, smartphone etc. It has been confirmed working with Windows 7, Mac OS X, Linux (Ubuntu 12.04) and several Android devices.

Arduino RFCOMM

Arduino Mega with some compatible dongles

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Categories: Arduino, Bluetooth, USB Tags:

Xbox 360 controller support added to the USB Host Library

July 18th, 2012 88 comments

Update
A wireless Xbox 360 controller is now also supported via a Wireless receiver. For more information see the blog post.

Hi everyone. I just wanted to let you know, that I just added support for the Xbox 360 controller via USB to the USB Host Library. The code can as always be found at github: https://github.com/TKJElectronics/USB_Host_Shield_2.0.

Categories: Arduino, TKJ Electronics, USB Tags:

mikroElektronika ARM development tools

May 28th, 2012 No comments

Recently mikroElektronika has been so kind to send us a couple of samples of their latest ARM development tool series.

The latest mikroElektronika ARM development tool series


mikroElektronika is known for their broad range of development boards especially in the PIC series where the most common board is their EasyPIC board. Now they have done it again and come up with a new product line – the ARM series.
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Categories: ARM, Development boards, Reviews, Tools Tags: