The Raspberry Pi is one of the most acclaimed inventions of our days – a credit card sized computer with the potential to improve our lives in an incredible variety of ways, and educate a whole new generation of hardware and software engineers. In honor of the recent Pi Day (March 14th, or 3/14) and the recent launch of Raspberry Pi 2, here are five of the most interesting (and sometimes weird) innovations we could find that were built using the microcomputer of the future (strong enough, but hopefully not used to play awesome slots at Platinum Play).
1. Picrowave by Nathan Broadbent
According to his website, Made by Nathan, the web and mobile developer Nathan Broadbent first thought of a smarter microwave after reading a post on Reddit about how food should come with QR codes that tells the microwave what to do with them. He built a better microwave using the Raspberry Pi, with better sounds and a redesigned keypad, automatically updated clock – with voice commands, a bar code scanner, and the possibility to control it remotely using a smartphone. Continue reading
Microcontroller timers are meant to count clock cycles in hardware and there are many ways and configurations where timers are handy. First of all timers are meant to work purely in hardware without utilizing CPU, secondly timers help generate waveforms like PWM, trigger events, count time between events and so on. But there is one use that in most cases is missed and not documented – precise single shots that allow to generate only single pulse shot with precise length. And this method doesn’t require CPU to be involved – just set and forget.
The idea of this method lies in using fast PWM (refer to datasheet for more info) mode a bit differently. Normally in this mode timer works by counting to TOP value, somewhere in between there is a MATCH value where timer outputs HIG and drops to LOW when TOP is counted. This way there is a PWM signal generated. Josh came up with idea that in this case we can generate only single pulse by setting MATCH value above the TOP and set initial timer counter value above TOP. This way timer counts and when finds MATCH value it triggers pulse to HIGH level and keeps it until counter reaches MAX value and pulse drops to LOW. Next time when timer counts from zero to TOP it never reaches MATCH value and so no more pulses are generated. This way you get total control of your single shots that length can vary depending on initial settings. Pulse length can be as short as 63ns and there is no CPU involved. There is a C demo for that if you would like to experiment.
Raspberry Pi version 2 has changed playing rules between Linux boards. With raspberry Pi 2 here came faster CPU with four cores, RAM jumped to 1GB, so naturally we would expect faster speeds everywhere including GPIO. Joonas have ran several benchmarks to show the increase in numerical values, so we could make conclusions.
He run several common tests with available software libraries and GPIO access methods. Results actually look very promising as for almost all methods speed increased twice and more. For instance Python Rpi.GPIO based raw speed increased from 70kHz to 243kHz. Shell command driven IO became also 2.5 times faster. So this is great news for everyone who was struggling to the limits. For more info and benchmark tests go to GitHub.
It seems that ESP8266 WiFi module is successfully building a community around itself. And there are dozens of reasons for that. First of all – module is really cheap, then it can connect things to internet via WiFi and lastly it can be programmed as stand alone microcontroller by using Lua language. So it dives quite some opportunities.
Ray recently discovered its potential. In the beginning he was playing with this module like with any other unit which accepts AT commands from host controller and does bring WiFi connectivity. But then he gave a try to its programming capability. Of course there is an initial hustle to flash it with Lua firmware that enables it to be programmed with scrips (there is even an Arduino IDE for scripting). Then he thought that this module could be wrapped with some hardware to make things much easier for starters, so he built ESPToy board which plugs ESP8266 module with programmed Lua firmware, then it carries USB to serial converter for easier interfacing to PC, additional there are button and RGB LED.