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]
When i saw simpleavr’s implementation of usbtiny on attiny45 , i thought it would be cool if i make a kit version of this with a minimal form factor. Then i designed a PCB and sent for first prototype. Later on i thought, if i want to sell this, it would be much cooler ,and more suitable with “Open Source Hardware” concept, if i bring this project one step ahead. So i tried to fit anything extra to the device and this project came out.
Little Wire – tinyAVR based multi-tool - [Link]
If you spend any time playing with Arduinos, ATtinys or looking at AVR spec sheets, you soon encounter a bewildering smörgåsbord of acronyms for various communication protocols. With examples such as I2C, LIN, SPI, TWI, USI, etc., it can get pretty confusing. What do these terms mean? How do you choose the chip that meets your needs? How do you make use of these protocols? This guide will take the mystery out of all these acronyms, and provide a brief overview of what they mean and how you use them in your projects.
Guide to Arduino Communications - [Link]
AvrPhone is a simple mobile phone with a touchscreen. His brain is AVR microcontroller ATmega128 (128 kB flash, 4 kB SRAM) and user interface provides 2.4 “LCD display with touch foil and controller ILI9325B , equipped with 16-bit bus. The communication module provides GSM SIM100S čísnkého manufacturer Simcoe. The whole system is powered by a 3.7 V/1000 mAh Li-Pol cells.
AVRphone - [Link]