Have you ever been curious about the power consumption of an appliance? For example did you wonder how much it will cost you to leave your television in standby mode whole night? Or did you want to learn how much change your refrigerator settings will make on your electric bill? If your answer is yes, you can use a wattmeter to measure the power consumption of a device. In this project we are building one.
This is an AC Watt Meter which can measure the real power consumption of a device connected to the 230Vrms/50Hz mains line. The PIC microcontroller collects the voltage and the current information with the help of ADCs and then calculates the RMS voltage of the mains line, RMS current drawn by the device and the resulting average power consumption. All these information is then displayed on the dot matrix LCD.
DIY Digital AC Watt Meter - [Link]
Teensy-LC (Low Cost) is a powerful 32 bit microcontroller board, with a rich set of hardware peripherals, at a very affordable price!
Teensy-LC delivers an impressive collection of capabilities to make modern electronic projects simpler. It features an ARM Cortex-M0+ processor at 48 MHz, 62K Flash, 8K RAM, 12 bit analog input & output, hardware Serial, SPI & I2C, USB, and a total of 27 I/O pins. See the technical specifications and pinouts below for details.
Teensy-LC maintains the same form-factor as Teensy 3.1, with most pins offering similar peripheral features.
Teensy LC – Coming March 2015 - [Link]
Davide Gironi writes:
The PWM frequency have to be selected in the way that the switch frequency is much higher than the dynamics of the motor.
To avoid noise from the motor, the choosen PWM frequency is 20Khz. Which is a know to know frequency.
So, with this one, you can drive up to 4 motors independently controlling:
*slow start / stop
Setup parameters are contained in dcmotorpwm.h
This library was developed on Eclipse, built with avr-gcc on Atmega8 @ 8MHz.
Driving a DC motor using PWM with AVR ATmega - [Link]
Toshiba has added two new products to their ARM® Cortex®-M4F based TX04 series microcontrollers. The TMPM470FDFG and TMPM475FDFG are both capable of operating two brushless DC motors simultaneously.
The new microcontrollers aim to satisfy ever-increasing demand for more energy efficient motors and incorporate vectoring technology to ensure efficient motor control. The TMPM475FDFG also integrates a CAN (Controller Area Network) controller which is required for use in specialist factory automation systems. Both chips are ideal for a wide range of uses ranging from industrial applications to use in home appliances, such as washing machines, fridges and air-conditioning units.
The TMPM470FDFG and TMPM475FDFG are based upon the high-performance ARM® Cortex®-M4F and can operate at up to 120MHz. They incorporate two modules, each containing a programmable motor drive, 12-bit AD converter and vector engine, ensuring the efficient and simultaneous operation of two brushless DC motors from a single chip.
Toshiba Announces Two New ARM Cortex-M4F Based Microcontrollers - [Link]
An autonomous AVR ISP programming device with SD-Card, Nokia display, ZIF socket and standard 6-pin ISP interface:
From project to project the number of hex files on our PC was increasing. Many people send us their virgin ATMegas to get them flashed. And last not least distributing PCB’s and pre-flahed chips via agile-hardware forced us to burn many, many AVRs. In principle this is a work an ape should do but reality was different. So we spend munch time in this boring job. To much time …
Thus it was just consequent to think about a device that would do the job for us. Here is the result, the SolderLab Easy Auto Programmer V1.0. An All-in-one AVR programmer with SD-card, Nokia Display, a ZIF-Socket and a 6-pin ISP interface. With this device the programming of an AVR is done in seconds including the setting of fuse bits (before AND after flashing), flashing the chip, verifying the flash. And all this without any connection to the PC and by pressing just one single button. You just have to put all your hex files into a folder called “hex” on a standard FAT32 formatted SD card, put the card into the programmer an supply it with some voltage (7-20V). That’s it the rest is done by the “ape”.
Stand Alone AVR Programmer - [Link]
Shawon M. Shahryiar @ embedded-lab.com writes:
In embedded systems, oftentimes it is needed to generate analog outputs from a microcontroller. Examples of such include, generating audio tones, voice, music, smooth continuous waveforms, function generators, voltage reference generators, etc. Traditionally in such cases the most common techniques applied are based on Pulse Width Modulation (PWM), resistor networks and external Digital-to-Analog Converter (DAC) chips like MCP4921. The aforementioned techniques have different individual limitations and moreover require external hardware interfacing, adding complexities and extra cost to projects. XMega micros are equipped with 12 bit fast DACs apart from PWM blocks and again it proves itself to be a very versatile family of microcontrollers. In this post we will have a look into this block.
XMega DAC - [Link]
Jason Bowling writes:
Over the last year I’ve been working towards an underwater sonar system for ROVs and surface boats. In order to learn the basic signal processing required to detect the echoes, I initially got a simple sonar working in air with a desktop conferencing USB speaker/mic running on Windows. A writeup, including source, is here. That article describes the algorithms used in detail and would be a good read if you want the details of how this works.
The next logical step seemed to be to get it working on a microcontroller. There are plenty of low cost ultrasonic sonar modules available that work really well in air, but the idea was to work towards getting a sonar that worked in water. There are currently no low cost sonar modules for hobby use in water.
Audible Frequency Chirp Sonar with the Stellaris Launchpad - [Link]
Joe @ hobbyelectronics.net:
Here you will find complete construction details including circuit diagrams, PCB layouts and PIC firmware (and the source code). The code was written in Proton PIC BASIC but the good news is that there is now a free version of this compiler available for download; AMICUS18.
PIC Digital Thermometer & Clock - [Link]
ARM PRO MINI is a small barebone open source ARM M0 microcontroller board that is great for quick prototyping and as a starting point for your own ARM based custom designs. It was designed and named after the venerable Arduino Pro Mini and it is an excellent stepping stone for makers and hobbyists ‘graduating’ from Arduino to the ARM architecture.
ARM PRO MINI - [Link]
Ralph Doncaster writes:
Since the release of V-USB, dozens of projects have been made that allow an AVR to communicate over USB. USB data signals are supposed to be in the range of 2.8 to 3.6V, so there are two recommended ways to have an AVR output the correct voltage. One is to supply the AVR with 3.3V power, and the other is to use 5V power but clip the USB data signal using zener diodes. Most implementations of V-USB, like USBasp, use the zener diodes. I’ll explain why using a 3.3V supply should be the preferred method.
USB interfacing for AVR microcontrollers - [Link]