1-wire devices are commonly used in many applications. You probably are familiar with famous DS18B20 digital temperature sensor in TO92 package. They can be powered and interfaced using same single data line plus ground return of course. 1-wire originally was designed by Dallas Semiconductors Corp. which is also a major provider of 1-wire devices like temperature sensors, timers, real time clocks, memory and well known iButton.
1-wire interface is a bidirectional, half duplex slow serial communication standard. It doesn’t use any clock signal. When talking of speed, standard data rate is 15.4kbps. But there is possible to overdrive 1-wire communication to up to 125kbps. Continue reading
During time I’ve been purchasing or building various microcontroller boards. Most of them were used just to try things out or because they were cheap to get. So I thought, why not to blow dust away and see what we have here. Maybe there will be some fresh thoughts on where to use them.
Probably I should spare a few words about each of them. Continue reading
Recently I obtained a Samsung Galaxy Ace S5830 android mobile phone. It was released a year before but it seems to have enough power to run most of apps you can find around.
It is powered by Qualcomm MSM7227 ARM11 processor running at 832MHz. Has internal 158MB of internal memory and can support up to 32GB MicroSD flash card. Other features include GPS, WiFi, 320×480 TFT touch screen, 5MP camera and so on. Device is powered by Android OS v2.3. These are specs you can find on any mobile website. To get your own Samsung phone, check out phones4u.
Smart phone devices are as valuable as there are some useful apps there. So I started wandering if there are electronics/microcontroller related apps that could be useful in daily work. Lets see what can we find in app store. First of all we are interested in free apps. Search on AVR microcontrollers gave me coupe results: AVR Fuse Calculator and Using Atmega128 apps. Lets see what are they capable of. Continue reading
Some time ago we noticed that Cornel University ECE4760 project list started to build up. It seems that the project list is finished with 30 great projects built around AVR microcontrollers. Students as always prove to be creative and inspiring. Like each year they came up with new ideas and implementations. We like that they use free tools to build them. The compiler they use is WinAVR/GCC compiler. So everyone can replicate one or another idea if needed.
It is hard to go through whole project list as it would tike time and we still wouldn’t be able to tell the thing. Some of them really are worth attention like EEG Pong, where device reads brain waves and this controls computer cursor. Continue reading
In more complex projects where audio or video are involved, microcontrollers usually run out of internal RAM. The only solution that stands out is adding external RAM. Depending on platform and solution used there are many ways of doing this. But usually goes SRAM modules, latch register(s) and probably some other additional circuits. If you only need to add more RAM without planning all this you can use RAM module like this one made by [Wardy].
This is simple RAM module with 512Kbytes of static RAM. It only needs 13 pins for interfacing and can accept voltage levels 3.3V or 5V. PCB layout is designed so that pins are breadboard compatible – easy to play with any microcontroller or dev board like Arduino.