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9 Apr 2014


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]

8 Apr 2014


A beginner’s guide to AVR programming on instructables. It cover the basic setup to light up some leds.

Beginner’s Guide – AVR Programming - [Link]

5 Apr 2014


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]

31 Mar 2014


ARPix has posted this instructable on constructing an external serial monitor device using the Atmega328 MCU and a graphic LCD. It allows a user interface to set the serial baud rate and start/stop functions using tact switches.

Sometimes I needed an external serial monitor like the Serial Monitor in the Arduino Editor, to see what is going on. So I made one. For the ESM I used an Atmel Atmega328 because it have an internal SRAM with 2KBytes. It’s necessary for the big data processing. So you need more than 1KByte SRAM.


Constructing an external serial monitor - [Link]

19 Mar 2014


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]

24 Feb 2014

3d_pcb_1_thThis project is a controller for a dual pulse spot welder that has some nice features that are controlled using a LCD interface. Hercules Trapierakis writes:

I always wanted a spot welder, so I decided to built one. I wanted to build a capacitance discharge one but I couldn’t afford for the capacitors at this time. So this is a controller for a dual pulse spot welder with some few extras:

– It has a zero cross detector. You could power the transformer at zero cross or dim the transformer if you like
– The transformer is triac controlled
– It has an hd44780 interface
– An spi interface for single thermocouple
– Peak detector of a current transformer
– Isolated foot switch
– Voltage monitor with opmaps
– An attempt to sense when the user tries to weld
– Single rotary switch for operation and single rotary encoder for setting up

MCU Controlled Spot Welder - [Link]

20 Feb 2014


This project is a 7 segment LED display module that can be driven using SPI protocol, so it needs only 3 pins of your mcu to drive 4 x LED displays. It’s based on MAX7219 LED display driver.

Seven segment LED displays are very popular for displaying numeric information because they are very attractive and readable from a far distance and wider viewing angle.

The downside is they are resource-hungry. For example, it requires 12 I/O pins of a MCU to drive a 4-digit seven segment display using a standard time-division multiplexing technique.

Here I present a serial seven segment LED display module that can be used with any MCU using a 3-wire SPI interface. This particular display has four digits (0.40” size) and two colon segments (to support time display) display.

Serial 4-digit seven segment LED display - [Link]

16 Feb 2014


Exar have announced the 5 mm square SP335 transceiver chip which supports RS-232, RS-485 and RS-422 serial standards. It is a single chip solution between the serial comms port and the UART or MCU allowing system designers to cater for multiple serial protocols over the same connector. The transceiver’s programmable end-of-line termination and multiple configuration modes allow all three protocols to be used interchangeably over the same cabling and connector without the need for additional switching components.

Built in protection tolerates direct shorts to DC or AC voltages as high as ±18 V and severe ESD events. The chip features a separate supply voltage for the logic interface pins, which can be as low as 1.65 V. This allows direct interface with low voltage UARTs and MCUs without the need for level shifters. It also supports data rates up to 20 Mb/s in RS-485/422 modes and 1 Mb/s in RS-232 mode and can be slew limited to 250 kb/s toggling a single control pin. With no inductors or magnetic components, the on-board charge pump generates the RS-232 bipolar voltage levels from a single supply (3.0 to 5.5 V) using just four external capacitors. [via]

Transceiver Chip Handles RS-232, RS-485 and RS-422 - [Link]


14 Feb 2014

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]

6 Feb 2014


I present the new module MOD-20.Z Xmega eXploreGO of Modułowo, with the microcontroller ATXmega128A4U and MP3 decoder VS1003B. The module has an DataFlash memory and a microSD card connector. You can connect a Bluetooth module and a radio module nRF24L01. The module can be programmed via USB or programmed/debugged using the connector PDI, derived on the edge of the platform. All signals from the microcontroller are routed to external connectors. Signals connected to VS1003B and DataFlash have SMD jumper and they can be disconnected at any time, in the case of using signals for other purposes. On the edge of the plate also put a small switch ON / OFF for USB power.

The module has two configuration jumpers for selecting the power supply from the USB connector or the VIN. Xmega eXplore GO has a connector’s compatible with the Arduino platform, enabling connection of Arduino shield’s. Microcontrollers ATXmega tolerate voltage +3.3 V, each signal has a built-in resistor with a value of 3.6 kR, allowing you to connect systems +5 V. In some cases they can interfere, so most of the resistors has a SMD jumper on the opposite side. The module is available in two basic versions: with the block VS1003B (MP3 version) and without. A cheaper version will allow the use of the module as a development platform for microcontroller ATXmega128A4U. Below is a picture showing the contents of Xmega eXploreGO.

more info here: XMEGA EXPLOREGO ENG

Xmega eXploreGO – a new module with ATXMEGA mcu and mp3 support - [Link]





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