by Claude Haridge:
Microcontroller-based products sometimes require rotary switches. As many microcontrollers have an onboard ADC, it is easy to replace the rotary switch with a low cost potentiometer, when a rotary switch is too expensive or unavailable.
Although digitizing a potentiometer setting to act like a switch requires only a few instructions, an immediate problem is that instabilities in value occur at the switching threshold between one value and the next due to electrical or mechanical noise. The solution is to introduce upper and lower hysteresis thresholds about each transition so that the potentiometer needs to move beyond a threshold before another switch state is validated. For every updated switch state, another pair of thresholds replaces the previous. In this manner, the hysteresis provides clean switching between states.
Replace a rotary switch with a potentiometer - [Link]
Over a week ago I’ve got a notice that Texas Instruments (TI) is giving away a 50% coupon for MSP430_FRAM related devices. Without hesitation ordered their MSP-EXP430FR5739 TI experimenters board that price went down to $14.50 including free shipping.
MSP EXP430FR5739 FRAM based microcontroller board is interesting piece of hardware. It features FRAM memory instead of Flash which is claimed to withstand almost unlimited number of Reads and Writes. It is also faster. It can substitute an EEPROM on board. But it is not very popular technology due to different manufacturing. On this development board there is MSP430 microcontroller which has 16KB FRAM, 1KB of SRAM. It carries eight LEDS, MTC thermistor, 3 axis digital accelerometer, optional LDR, couple buttons. So this is great for many uses.
Experiment with MSP430 FRAM board via web interface - [Link]
Microchip Technology Inc today announced from EE Live! and the Embedded Systems Conference in San Jose the PIC16(L)F170X and PIC16(L)F171X family of 8-bit microcontrollers (MCUs), which combine a rich set of intelligent analog and core independent peripherals, along with cost-effective pricing and eXtreme Low Power (XLP) technology. Available in 14-, 20-, 28-, and 40/44-pin packages, the 11-member PIC16F170X/171X family of MCUs integrates two Op Amps to drive analog control loops, sensor amplification and basic signal conditioning, while reducing system cost and board space. These new devices also offer built-in Zero Cross Detect (ZCD) to simplify TRIAC control and minimize the EMI caused by switching transients. Additionally, these are the first PIC16 MCUs with Peripheral Pin Select, a pin-mapping feature that gives designers the flexibility to designate the pinout of many peripheral functions. The PIC16F170X/171X are general-purpose MCUs that are ideal for a broad range of applications, such as consumer (home appliances, power tools, electric razors), portable medical (blood-pressure meters, blood-glucose meters, pedometers), LED lighting, battery charging, power supplies and motor control.
Microchip Releases 8-bit PIC Micros with Intelligent Analog and Core Independent Peripherals - [Link]
bgyroscope @ www.instructables.com writes:
This instructable will show you how to build your own stopwatch to record multiple splits using an ATmega328 programmable microcontroller. When one presses the start button (or slaps the metal band in my watch), the screen displays the last lap for a second then continues the time on the next lap. It’s great for all you runners out there doing an interval workout.
Lap Stopwatch with ATmega328 Microcontroller - [Link]
bogdan informed us about his latest post on electrobob.com. It’s about a level translator for WS2812 LEDs. He writes:
WS2812 LEDs are one of my favourite toys. Apart from all the things that you can do with them in terms of lighting, displays or even light painting you can also use them for your projects as indicator lights.
The great advantage comes from the fact that you can use a single pin to drive so many of them and it takes just 3 wires ran across the whole box for practically any number. This in turn comes with the disadvantage of more complex control and problems driving them (5V devices) from a 3.3V microcontroller.
WS2812 level translator - [Link]
This soldering station controls a 24v 50W solder. Based on ATmega328p microcontroller, with combination of IRL3103 or IRFZ44 MOSFET, 5v 0.5A and 24v 3A power supplies,1500uF 35v capacitor, DS1307 – Real Time Clock, MAX7219 – 4 digit 7 segment LED driver, LEDs and other electronic components. Hakko 936 soldering iron handle with thermocouple control. A LM358 amplifies signal from thermocouple with gain 101.
DIY Soldering Station - [Link]
Here is a very nice build of a LED heart that creates incredible animations. Check it out.
Today we present the perfect Valentine gadget: just shake it and it will turn on and crate incredible light animations. That will be cool for sure!
We know that, as it’s Valentine’s Day, looking at the device described in this post you’ll be inclined to think that this is the usual heart-shaped Valentine gadget: in reality this is something much cooler as it’s capable to create beautiful and complex light games. Is based on the smallest microcontroller manufactured by Atmel: the ATtiny85.
Hack your Valentine with HeartThrob - [Link]
It consists of a power supply, the basic components for running the microcontroller (i.e. crystal, reset pin, …) and ICSP connector for In-Circuit programming. All pins are available on a header strip, so it is ideal for rapid prototyping.
PIC16F/18F Experiment Board - [Link]
DigiPot is a digital potentiometer using a rotary encoder as input along with a 7 segment display that show the current pot value.
The “potentiometer” is actually a rotary encoder (TW-700198) connected to a microcontroller that reads the signal from it and convert it to a value that is displayed on 7-segment displays. The value also is sent via i2c/spi/serial/usb to the host. Also 3 LED and included for status indication.
DigiPot – Rotary Encoder Potentiometer - [Link]
The solution is an embedded module. Swedish company Embedded Artists will help you in tit by their top-class modules with NXP processors.
Embedded modules are still more used in many products, where so far a classic microcontroller was sufficient. As requirements for functionality of devices are increasing, including audio/video output, network- and USB connectivity, as well as a possibility to be programmed by a user, to change firmware, etc, the development is more and more demanding. For small and middle-sized companies it can easily happen, that in respect to a supposed sale, the expenses will never return. In the most cases, it´s better and at the end of the day even cheaper to rely on some of so called embedded modules. An embedded module (depending on a type) usually provides all necessary for controlling of our device and it is usually easily programmable thanks to a standard OS implemented (Linux, Android, Windows,…).
Embedded Artists products are based on top-class NXP processors LPC with Cortex M0, Cortex M3 and Cortex M4 cores, but also on older ARM7. As Embedded Artists have a closed cooperation with NXP (they are an NXP certified partner), they have an excellent knowledge of these perspective chips. Among
Embedded Artists can be found:
- development kits
- OEM boards suitable for direct usage in products
- “quick-start” boards
- education boards
- display boards
- various accessories for development support
From a final product and production point of view, the most interesting are the OEM modules. Embedded Artists provides a wide support to their products and for example notes for usage of OEM modules in praxis can be found in the OEM Integration guide. An example of a price calculation – decision “own development or an embedded module” is illustrated in the attached picture. Many Embedded Artists products are in our stock ready for immediate shipment. We´re able to deliver you any other Embedded Artists product with a short leadtime.
Long development or better a short time to market? - [Link]