Alexander Holler writes: [via]
This page describes how you can use a small AVR device and a real-time clock (RTC) to build a hot-pluggable USB real-time clock (I’ve named it just usb-rtc), mainly for usage with ultra-low-cost hardware meant to be used with Linux.
The overall cost for one of those thingies I’m describing here is about 15€-20€, which isn’t really cheap. But I find it a valuable thingy because the result is a hot pluggable RTC, usable by almost any device which has USB. So it’s very likely you will use it for much longer than the device you currently want to build or search it for. In addition you might want to use it as a (hot pluggable) USB-I2C adapter too. The software I’m describing below already supports that.
How to build an USB real-time clock - [Link]
XMEGA-A1 Xplain development kit provides a straightforward way to development of applications with Atmel XMEGA microcontrollers.
XMEGA a family of powerful 8/16-bit RISC microcontrollers with many built-in peripherials (DMA, RTC, LCD driver, 12 bit ADC,…) is ideally suited for relatively high performance applications, where we will with favor use its features – often without a need to add any other peripherials.
In order to get easily familiar with AVR XMEGA family features, ATMEL also produces fevelopment/ evaluation kits for these processors. From several types available, in our offer you can find on stock the XMEGA-A1 Xplain with the ATxmega128A1 processor. The development kit enables development and testing of applications including usage of ADC, DAC and I/O ports. The kit is power-supplied via a USB port, that´s why you can supply it from a PC but even from an external AC adapter with an USB connector output. A detailed description can be found in the Xplained user guide, Xplained getting started and Xmega basics training documents.
On the Atmel website you can find many documents about various processor´s parts and its usage in the concrete applications.
Atmel AVR Xplain will explain it to you directly - [Link]
Michael Holachek writes:
The Arduino is a great platform for rapid prototyping because it’s so easy to use, well supported, and has a huge online community. However, sometimes you might want to make a smaller, cheaper, and more minimalistic circuit that can be put into permanent projects. Or, maybe you are wondering how the Arduino works. In any case, you’ll just want the brain of the Arduino: the AVR microcontroller. This chip contains the program that runs the Arduino.
Once you have just the AVR, you might be wondering how to program it. Since you no longer have a USB connection, how do you upload code? It turns out that the Arduino can program AVR chips! Let’s get started.
Programming an AVR with Arduino - [Link]
DUE ARM-powered Arduino – [via]
Far removed from the legions of 3D printers featured at this year’s Maker Faire in New York was a much smaller, but far more impressive announcement: The ARM-powered Arduino DUE is going to be released later this month.
Instead of the 8-bit AVR microcontrollers usually found in Arduinos, the DUE is powered by an ATSAM3X8E microcontroller, itself based on the ARM Cortex-M3 platform. There are a few very neat features in the DUE, namely a USB On The Go port to allow makers and tinkerers to connect keyboards, mice, smartphones (hey, someone should port IOIO firmware to this thing), and maybe even standard desktop inkjet or laser printers.
ARM-powered Arduino - [Link]
One tool that I’ve been missing at my lab at home is function generator. They tend to be a bit expensive, so I haven’t bought one. I thought this might be a good opportunity to try and make one myself. I found a pretty common DDS (direct digital synthesis) chip, called AD9833. Then just strap a USB-enabled AVR micro there and maybe some analog electronics.
This board doesn’t do any of the special analog magic to allow for variable amplitude or offset for the signal. The output is fixed to 0-4v. I’m planning to make another completely analog board for adjusting amplitude and offset.
AD9833 – based USB Function Generator - [Link]
A little known feature of Arduinos and many other AVR chips is the ability to measure the internal 1.1 volt reference. This feature can be exploited to improve the accuracy of the Arduino function – analogRead() when using the default analog reference. It can also be used to measure the Vcc supplied to the AVR chip, which provides a means of monitoring battery voltage without using a precious analog pin to do so.
Secret Arduino Voltmeter – Measure Battery Voltage - [Link]
Controlling temperature has been a prime objective in various applications including refrigerators, air conditioners, air coolers, heaters, industrial temperature conditioning and so on. Temperature controllers vary in their complexities and algorithms. Some of these use simple control techniques like simple on-off control while others use complex Proportional Integral Derivative (PID) or fuzzy logic algorithms. In this project Shawon Shahryiar discusses about a simple control algorithm and utilize it intelligently unlike analogue controllers. Here are the features of this controller:
- Audio-visual setup for setting temperature limits.
- Fault detection and evasive action.
- Temperature monitoring and display.
- Audio-visual warning.
- System status.
- Settable time frame.
- Data retention with internal EEPROM memory.
Intelligent temperature monitoring and control system using AVR microcontroller - [Link]
Scanalogic-2 PRO is a 4 channel Logic Analyzer and Digital Signal Generator priced at 59€. At this cost it’s easy for a hobbyist to get one and make digital circuits debugging a breeze. It’s designed to capture, decode and analyze serial protocols like SPI, I2C, UART, 1-WIRE and CAN in a few clicks. Data is captured on PC using the free and efficient ScanaStudio software.
- 20 Million Samples Per Second
- 4 Input/Output channels
- 256K Sample per channel
- 2V, 2.8V, 3.3V, 3.6V and 5V logic levels support
- Serial protocols decoders (SPI, I2C, 1-WIRE, UART, CAN, LIN,Manchester)
- Various trigger options
> Download features PDF
What you can do with Scanalogic 2
- Capture and Analyze signals – Serial protocols sampling, decoding, debugging (UART, I2C, SPI, CAN, 1-WIRE, LIN, Manchester,…)
- Save captured data and playback them later or on the other side of world!
- Generate PWM, FM or UART signals
- Capture images of your signals for demostration.
- Digital PWM and FM signals analysis (FFT)
- Compare captured signals.
- Use “mixed” mode to play a signal and record response on another channel (at the same time!)
- Generate your own data (PWM, FM, Serial Data)
- ScanaStudio PC software offers smooth scrolling and navigation options.
The Akafugu LED Candle is an artificial candle that imitates the flickering of a real candle. Use it in place of a real tea candle: It will fit inside a tea candle casing or any holder made for tea candles.
- Randomly flickering LED: Imitates a candle
- Fits inside a tea candle casing
- Open Source Firmware (available at GitHub)
- Open Source Hardware: Eagle PCB design files available at GitHub
- On-board ISP header for upgrading firmware
LED Candle - [Link]
The AVR Stick is a simple data logging device that instantiates itself as an HID keyboard and reports the voltages, along with a ‘timestamp,’ from two pins on an ATtiny85. The device uses open source firmware availabe from Objective Development (http://www.obdev.at/vusb/) called V-USB to implement the USB 1.1 standard. The code that runs the application was based on the EasyLogger example application from Objective development.
AVR Stick – A simple USB data logging device - [Link]