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29 May 2015

This project demonstrates how to design a wireless electronic notice board using SST89E516RD-40-C-PIE microcontroller. The notice boards are important in public places like railway stations, parks and airports. Presently almost all electronic notice boards are designed using wired system. One of the drawbacks of the design is the system’s flexibility in terms of placement. The aim of this project is to develop a wireless notice board that can be installed in any public areas and will display the latest information sent from the user’s mobile.

The above circuit consists of Microchip Technology’s SST89E516RD-40-C-PIE microcontroller, GSM module, level converter and 16×2 LCD. The LCD is connected to P1.0 and it is used to display message. The GSM module is connected to the SST89E516RD-40-C-PIE microcontroller through the MAX232 IC. Only four data lines are required to display the data, which are connected to P1.4, P1.5, P1.6 and P1.7 respectively. In order to communicate with GSM, some AT commands are sent through the serial connection (UART Protocol). The module requires 9600-baud rate. The GSM modem is duly interfaced through level shifter IC for establishing RS232 communication protocol to the microcontroller. The message received is sent to the microcontroller that further displays it on electronic notice board, which is equipped with a LCD display. It is interfaced to a microcontroller from 8051 family duly powered by a regulated power supply.

This GSM based e-notice board has various applications used in several domains including banks, stock exchanges, traffic control, public advertisements, and educational sectors. Further development to this project can be done by providing message storage facility by non-volatile memory i.e. EEPROM attached to the microcontroller for retrieval of old messages if required. It can also be expanded to a bigger LCD screen.

Wireless Electronic Notice Board using GSM  – [Link]

29 May 2015


by elektormagazine.com:

The PAM8905 is a new audio amp chip from Diodes Incorporated measuring just 1.5 x 2.0 mm. The design operates in class D mode, achieving a total harmonic distortion of 1% (plus noise) and delivering a maximum of 1.9 W into 8 ohm using a power supply in the range between 2.8 V to 5.2 V. The PAM8905 features an integrated boost converter powering the output stage to achieve the rated output power and maintaining volume with falling battery voltage. The boost converter is a fully synchronous design, ensuring a low external component count and high efficiency.

Tiny audio amp produces 1.9 W from 5 V – [Link]

29 May 2015


Nuimo is a universal controller for the internet of things. Control your music, lights, locks and more.

Nuimo is an intuitive and natural way to interact with your connected devices. Nuimo works with any bluetooth device or application including Sonos and Philips Hue.

Nuimo is a freely programmable controller and wireless so you can take it anywhere. Using the nuimo you can control all of your devices through our simple and seamless physical controller.

Unlike the touch screen, nuimo has a number of touch based inputs that feel familiar and suit your needs. It incorporates capacitive touch, gesture recognition and a 360 degree analog ring that gives you precise control over everything from the volume of your music to switching off your lights. These inputs are easily mappable to the devices and applications you care about most.

Nuimo: Seamless Smart Home Interface – [Link]

29 May 2015


Mohamed Afzal has written an article detailing how to send data to Thingspeak.com with ESP8266 + DS18B20 temperature sensor:

The stock Firmware in the ESP8266 supports AT commands and for communicating with this need an micro-controller like Arduino. But i want to make a simple solution for that without using external micro-controller. NodeMCU firmware was the best thing i found. To upload the NodeMCU firmware please do a google search, there are tons of video’s and supporting documents out there. I am not going to explain the flashing in this post.
NodeMCU is Lua based firmware and i hope most of the people will know it. Most router GUI also built by Lua.
If you are done with the flashing the ESP8266 module, lets connect the DS18B20 to GPIO 0. If you are not aware of pin mapping please check it before connecting anything to the module.

ESP8266 + DS18B20 Temperature sensor sends data to Thingspeak.com – [Link]

29 May 2015


Steve made this 6 volt 5 watt solar charge controller project, that is available at Github:

Here is a 6 volt 5 watt solar charge controller project using a dedicated printed circuit board from dirtypcbs.com and an Arduino pro-mini.
The board uses sot-23 low RDSon P channel mosfets (Si2369). It has voltage and current sensing, and 3 configurable switched or unswitched outputs.

Additionally, using a Bus Pirate you can grab charge controller voltages, currents, and other variables at 5 times a second using a Python3/tkinter program I wrote to go with this project. This program uses uses I2C to connect to the Arduino.

6 Volt 5 Watt solar charge controller – [Link]

28 May 2015


Desoldering braid makes an invaluable service at development or rework.

Everyone who´s ever tried to suck off a solder from a solder pad by means of a solder absorbing braid (wick) will probably confirm, that this tool belongs to a “must have” equipment of every professional or amateur workplace. What´s the charm of a desoldering braid? Above all in the fact, that it´s able to absorb almost all the solder from a given place, thus the most of components can be loosened very easily. Hand (pneumatic) pump surely has its place, mainly when working with bigger components, but at comparison with a desoldering braid it´s similar like if we compared a broom with a vacuum cleaner.

A quality desoldering braid is usually able to absorb a solder so thoroughly, that only a microscopic layer of a solder will remain on a PCB – as if a board was new, unused. It is very advantageous even at a hand rework of SMT components, because it´s desirable the component to lay directly on a board – not askew in a thick solder layer causing a mechanical tension and able to cause even a malfunction of a component (often at SMT capacitors).

To reach a good functionality of a desoldering wick it should be made of a fine gauge copper wires (without oil residues end similar) and it must be treated with a high quality flux. The cheapest braids usually contain only a rosin-based flux, the better ones have a synthetic flux based, which produce less fumes.

A novelty in our portfolio is the novelty from company CRC Industries – braid SOLDABSORB. We keep Soldabsorb in a width of 1.5 and 2.5mm, packed in a blister in 2 pcs (the price is for 2 pcs). Soldabsorb represents a top-level in this segment and is made of a highly pure copper, fine gauge wires and contains a synthetic NO-CLEAN flux. It means, that the flux residues are non-conductive and non-corrosive and they can be left on a PCB. Very fine wires contribute to a high wicking (absorbing) ability.

The usage of the wick is very simple and is based in 4 steps:

  • Place the Soldabsorb wick on the solder joint
  • place the tip of the solder iron on the wick and hold shortly
  • absorbed solder will change a color of a braid, showing that the process was successful
  • when a joint contains a big amount of solder, it may be necessary to cut off a used end of a braid (2-5mm) and repeat the process

In praxis it approves well to adjust temperature of a soldering iron to a slightly higher, than we´d normally need for a given pad and eventually also to use a thicker soldering tip. In especially difficult cases (vias at ground planes of a PCB) it helps to put a small amount of a new solder on a soldering tip, which will decrease an absorbing ability of a braid, it will significantly improve a heat transfer from a tip through a braid to a PCB, thus improving and speeding up an absorption. Before another use of a braid, it´s sufficient to cut off only a very end of a braid (a few mm) fully sucked by a solder.
At the end it´s worth to mention, that after desoldering, it´s good to apply a small amount of solder on a soldering tip to protect it from oxidizing.

Detailed information will provide you the Soldabsorb datasheet.

Desolder professionally with NO-CLEAN flux wicks – [Link]

28 May 2015

The IEEE 802.15.4 standard is the fourth task group of the IEEE 802.15 working group, which defines Wireless Personal Area Network (WPAN) standards. The IEEE 802.15.4 market has the following advantages; low power consumption, low cost, low offered message throughput, supports large network orders up to 65k nodes, low to no QoS guarantees, and flexible protocol design suitable for many applications. The purpose for this standard is to empower simple devices with a reliable, robust wireless technology that could last for years on standard primary batteries. It is designed to allow developers to effectively use and benefit from radios based upon the standard.

This reference design is a low cost System-on-Chip (SoC) solution for the IEEE 802.15.4 standard that incorporates a complete, low power, 2.4GHz radio frequency transceiver with TX/RX switch, an 8-bit HCS08 CPU, and a functional set of MCU peripherals into a 48-pin LGA package. This product targets wireless RF remote control and other cost-sensitive applications ranging from home TV and entertainment systems to medical and supports all ZigBee node types. The Freescale’s MC13237 is a highly integrated solution, with very low power consumption. The MC13237 contains an RF transceiver that is an 802.15.4 standard 2006 compliant radio that operates in the 2.4GHz ISM frequency band. The transceiver includes a low noise amplifier, 1mW nominal output Power Amplifier (PA), internal Voltage Controlled Oscillator (VCO), integrated transmit/receive switch, on-board power supply regulation, 12-bit ADC and full spread-spectrum encoding and decoding.

This design is not only limited for remote controls. It can also be used as the basis for wireless devices and other sensor-controlled application that used IEEE 802.15.4 standard. The IEEE 802.15.4 radios have the potential to be the cost-effective communications backbone for simple sensory mesh networks that can effectively carry data with relatively low latency, high accuracy, and the ability to survive for a very long time on small primary batteries.

SoC Remote Control Platform for IEEE 802.15.4 Standard – [Link]

28 May 2015


by RFduino @ instructables.com

The RFduino compass is a fully functional stand-alone compass which also transmits the current heading via Bluetooth low energy technology to phones, tablets, personal computers or any other equipped device. The RFduino compass is known as a Bluetooth Smart device.

RFduino Compass – [Link]

28 May 2015


Dan blogged about his Servo tester with OLED display project:

The problem is simple: I need to have a reliable and easy to use servo tester, that I can use to test/play with a standard RC servo or ESC or anything else that uses the same control protocol. This necessity has arisen again quite recently, while working on the 2nd iteration of my ball balancing device.

Double RC servo tester with OLED display – [Link]

28 May 2015


by João Vilaça @ vilaca.eu:

If you love classic games like Tetris (source code) and Breakout you can now build an Arduino console to play games on the go and in color. Youtube gameplay demo.

As most inexpensive LCDs work at 3.3v the Arduino for this project works at 3.3v too.

At only 8MHz the Arduino Pro Mini 3.3v is slow by today’s standards but fast enough for most classic games.

Other Arduinos or compatibles can be used in its place. If an 5v Arduino like the Uno is used you must use a Level shifter from 5v to 3.3v or you’ll risk frying the TFT.

Build an inexpensive handheld Arduino color console – [Link]





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