by MIKE BARELA @ adafruit.com:
Trinket lends itself very well to building clock projects, its small and easy to hide behind a larger display. And clocks don’t need a lot of logic, this example only has maybe 20 lines of code. Adding a digital display via I2C is possible using seven segment or character-based displays (with the library code posted for other projects).
This project interfaces Trinket to the the Adafruit DS1307 real-time clock (RTC) breakout board to form a clock. But in a twist, the display is done using two analog meters. One for hours, one for minutes.
The Trinket can output to a meter without digital to analog converters. Trinket has pulse width modulation (PWM) on three of its pins. The meter uses a moving coil inductance movement, acting to average the indication of current flowing through it. If you have narrow pulses, the average voltage it sees is lower, thus the current is lower for the fixed resistance attached to it. For wide pulses, the meter sees nearly the supply voltage and will stay around the full scale. This circuit varies the pulse width sent to the meters proportional to the hour of the day and the minutes after the hour.
Meter Clock using a DS1307 RTC and Trinket Microcontroller – [Link]
by Steven Keeping @ digikey.com
The wearables market is booming. Statistics aggregator web portal Statista, notes that the global market will be worth over $7 billion this year and $12.6 billion by 2018.
Although the potential rewards are high, this is not an easy market to enter. Designing smart watches or fitness bracelets is tough; consumers expect lots of functionality, smartphone connectivity, compact form-factor, light weight, and long battery life. The introduction of highly integrated, ultra-low-power microprocessors and wireless chips has eased the design process, but squeezing out all of the battery’s power remains key to a wearable product’s success.
This article takes a look at how silicon vendors help wearables designers extend battery life by offering power-frugal displays, microcontrollers (MCU), silicon radios, and power-management chips designed specifically for ultra-low-power applications.
Extending Battery Life in Wearable Designs – [Link]
This project is a versatile, configurable, and cost effective development board available for the 16F628A or other 18 PIN Microcontroller from Microchip. The board has simplest form with all the Port pins terminating in a Relimate connector (Header Connector) for easy connection to the outside world.
16F628A Microcontroller development board – [Link]
LAPIS Semiconductor has recently announced the development of a low power microcontroller that has an integrated 8-bit low power MCU core, speech synthesis circuit, highly efficient Class-D speaker amp, non-volatile memory and oscillator circuit on a single chip, making audio playback possible by simply wiring up a speaker.
The ML610Q304 has a typical audio power output of 450 mW operating at 3 V or 1 W at 5 V. The controller includes four 8-bit counters which can be combined to make two 16-bit timers, a three channel 10-bit A/D converter, a two channel SSIO, UART and I2C peripheral interfaces. The memory capacity of the ML610Q304 includes a 96 KB program flash, 2 KB data flash and 1 KB RAM. The dedicated hardware-based audio playback helps reduce CPU loading. Two suggested audio playback formats are 16 kHz 16-bit PCM and 16kHz HQ-ADPCM. The Class-D amp reduces current consumption during audio playback by approx. 40% compared to conventional solutions, making it a good choice for incorporation into mobile battery-powered devices. In recent years a growing number of electronic products are adding voice playback functionality, particularly battery-driven devices that require increased miniaturization and lower power consumption for longer operating life.
8-bit MCU with built-in 1 W Audio Amp – [Link]
Praveen from CircuitsToday has written up an article on interfacing PIR sensor to 8051 microcontroller:
PIR sensors are widely used in motion detecting devices. This article is about interfacing a PIR sensor to 8051 microcontroller. A practical intruder alarm system using PIR sensor and 8051 microcontroller is also included at the end of this article. Before going in to the core of the article, let’s have a look at the PIR sensor and its working.
Interfacing PIR sensor to 8051 microcontroller – [Link]
As any beginner electronics hobbyist I have recently came to conclusion that using Arduino (or even Mega328) for small projects is neither cost-effective or educational (I’ll explain why later).
Another reason for writing this article is that I came across few ATTiny13A-SSU chips @ less than $0.90 each, which is even lower the official retail price, so I just had to buy 5 of them, although I didn’t know at the time whattahellamigointodowithit what is it really capable of.
Starting with ATTiny13 – [Link]
by silentbogo @ instructables.com:
If you previously worked(or currently working) with small 8-bit microcontrollers, like ATTiny or PIC12, you’ve probably encountered a fundamental problem of not having enough GPIO pins for your needs or project requirements.
Upgrading to a larger MCU is only one of the options, but as usual there is an alternative. In this article I will explain how to use shift registers in some common situations in order to expand the I/O capacity of your microcontroller. As an example I will use an ATTiny13A and a 74HC595 shift register.
Getting more I/O pins on ATTiny with Shift Registers – [Link]
This is a versatile, configurable, and cost effective Development Board designed for the 18F 28 pin series of Microcontroller from Microchip. The board is simplest form with all the Port pins terminating in a header connector for easy connection to the outside world.
PIC 18F – 28 PIN PIC Development Board – [Link]
This project provides you a simple and easy solution to connect / convert your Microcontroller input/output to be connected to the serial port of the Computer.
This projects build around popular MAX232 level shifter IC to do the Level Shifting (Voltage) between 5 V and 12 V DC.
An Onboard 9 pin female D connects this PCB to the Serial Port cable (not supplied with the Kit). Connector J1 connects to the Host for power supply and serial In/Out signals.
A Provides data from the Computer to the Host (RXD)
B Provides data to be sent to the Computer from the Host (TXD)
RS232 – MAX232 Interface Module – [Link]
by Richard Quinnell @ edn.com
Texas Instruments has launched the MSP-432, a Cortex-M-based microcontroller that aims at providing developers with a higher-performance upgrade path for MSP-430 users while still retaining low-power operation. The 32-bit processor uses an M4F core with FPU and DSP extensions, achieving a CoreMark score of 3.41/MHz and a certified ULPBench score of 167.4, among the highest in its performance class.
The device can operate at full speed down to a supply of 1.62V, simplifying direct sensor interface. It specs an operating current of 95 µA/MHz and a sleep mode current of 850 nA with its real-time clock running. The device also contains a number of architectural features that support reduced power consumption while boosting performance.
MCU blends low power and high performance – [Link]