IrDA Interface for Portable Devices

IRDA

The circuit uses a SC16C650 to implement an IrDA interface. Infrared Data Association (IrDA) has defined a group of short-range, high speed, bidirectional wireless infrared protocols, generically referred to as IrDA.

The hardware section is composed of SC16C650 which is electrically hooked-up to an IrDA transceiver module. The electrical connection between the SC16C650 and an IrDA transceiver module is very straightforward, no external component is required except an inverter to invert the IrDA output signal. Besides the power supply noise-filtering components, the only other component required is a 14 Ω resistor. This resistor sets the current through the IR emitter, hence the power output of the transceiver.

IrDA Interface for Portable Devices – [Link]

Automation Board

automation_board

Thinking about using Arduino to automate your home? Do it easily with our compatible board!

The Automation Board is 100% compatible with the Arduino Uno. This way it allows the enjoyment of all the easy programming and libraries that Arduino provides. It’s a strong and versatile board, with multiples resources to develop a fully automation system. The Automation Board dispenses the use of power sources.

Automation Board – [Link]

Pocket Voltage Supply: A USB Powered Variable Voltage Supply

usb_psu

The Pocket Voltage Supply plugs into any 5V USB hub & allows the user to output 5V,3.3V,2.5V,1.8V,&1.5V. Use it for all your projects!

The Pocket Voltage Supply is a USB powered variable voltage supply. It can be powered with any 5V USB hub and can supply up to 1.5A. 5V USB hubs can be found almost anywhere; desktop computers, laptops, cell phone chargers, even portable USB battery banks. Pairing the Pocket Voltage Supply with a portable USB battery bank allows the user to test circuits and prototypes outside of a lab setting and even bring testing to the field!

Pocket Voltage Supply: A USB Powered Variable Voltage Supply – [Link]

High Voltage Buck-Boost Regulator

8056

The LTM8056 from Linear Technology is a 58 VIN, buck-boost μModule® (micromodule) regulator which requires just a few external passive components to complete the regulator design. Included in the package are the switching controller, power switches, inductor and support components. The basic external components needed are a single resistor to set the switching frequency, a resistor divider network to set the output voltage together with input and output capacitors. Other features such as input and output average current regulation may be implemented with just a few additional components. The LTM8056 operates with an input voltage ranging from 5 V to 58 V and can supply a regulated output voltage between 1.2 V and 48 V. The SYNC input and CLKOUT signal output provide clock synchronization options.

High Voltage Buck-Boost Regulator – [Link]

Tiny real-time clock consumes only 240 nA

Micro Crystal RV8803C7

by Susan Nordyk @ edn.com:

Furnished in a ceramic surface-mount package that is just 3.2×1.5×0.8 mm, the RV-8803-C7 real-time clock module from Swiss manufacturer Micro Crystal consumes 240 nA and operates from a supply voltage as low as 1.5 V to increase the life of backup supplies. The device gives designers the option to replace expensive batteries and supercapacitors with low-cost multilayer ceramic capacitors for battery backup.

The temperature-compensated real-time clock is accurate to within ±3.0 ppm (±0.26 seconds/day) over a temperature range of -40°C to +85°C. In addition to low current consumption and high accuracy, the RV-8803-C7 has one of the smallest ceramic packages in the industry with an integrated 32.768-Hz quartz crystal. It operates from a supply voltage ranging from 1.5 V to 5.5 V and employs an I2C interface.

Tiny real-time clock consumes only 240 nA – [Link]

With MCP73831 you’ll charge lithium cells easily and safely

obr1695_uvod

 

And it can be added that also simply and cheaply. MCP73831 from company Microchip is „all-in-one“ solution for charging a single Li-ion/Li-Po cell.

Li-Ion a Li-Polymer cells are becoming a No.1 choice for many applications, where they persuade by high energy density, low weight, low self-discharge and for majority of applications also by their favorable flat shape (Li-Po). Their price is also affordable (in regard to their properties) and so there´s usually only one “difficulty” – to solve charging, or more exactly – overall management of these cells. Basic principles were highlighted to you in our article “Try the most favourite types of batteries”. To reach a maximum cell lifetime, it´s also advisable to use initial (preconditioning) slow charging and also important is a proper charging termination as well as repeated recharging after reaching a certain degree of discharge.It´s obvious, that to construct such a circuit from discrete components would be possible, but impractical, bulky and expensive. That´s why there are various charging controllers on the market and in many cases a single chip solution is an ideal solution. This is also a case of MCP73831 chip – a fully integrated linear charging controller. If you use only a single cell and maximum charging current of 500mA is sufficient for you, then MCP73831 will meet all requirements for a quality and safe recharging solution. MCP73831 has integrated output (FET) transistor, current sensing and reverse discharge protection.

Charging current can be easily adjusted by a single resistor, what´s also associated with other parameters like preconditioning current and charging termination. MCP73831 also contains a thermal regulation, which decreases output current in case of increased chip temperature (for example because of higher ambient temperature).

MCP7383x is available in four versions with factory-set regulation (max. charging) voltage. In our store can be found “the safest” first version with 4.20V regulation voltage – MCP73831T-2ATI/OT. In datasheet (p. 25) we can also read that this is the “AT“ version, which starts repeated charging at 94% Vreg (i.e. at approx. 3.95V), in a SOT23-5 package. Supply voltage can be in a range of 3.75-6V, while in respect to a thermal stress of a chip it´s better to supply it by a voltage close to max. output voltage (4,20V).

The chip can be easily supplied by a standard 5V voltage, but in cases of increased risk of overheating (operation at higher ambient temperatures, densely populated PCB,…), a common Si diode in series can be helpful. This will decrease supply voltage in 0.6-0.7V (and takes a portion of thermal loss on itself).
Charging status can be found at the “Charge status output” pin, which can drive an indication LED or can be connected to a host microcontroller.

With MCP73831 you’ll charge lithium cells easily and safely – [Link]

Electronic Mosquito Repeller

 

Mosquito_Repeller

This circuit is built to repel mosquito using high frequency sound. The design is comprised of LM555 timer which provides the pulse generation and precision timing. It is also a stable controller capable of monostable or astable operation. The 74HCT4017BQ device is a Johnson decade counter with 10 decoded outputs. It provides the signal to be fed into the 555 timer which is connected to the output piezo speaker. The piezo speaker generates the sound. The Bipolar Junction Transistors(BJT) BC337 and BC327 acts as the amplifier of the output sound. It forms the push-pull amplifier that is more efficient than a single-ended Class A amplifier.

Electronic Mosquito Repeller – [Link]

Solar self-rechargeable Battery

DSC01788

This is a prototype model Battery (type C ) for electronic devices. The battery has the ability to be recharged by the sun and don’t need any battery charger. It is necessary for climbers, explorers, soldiers, free camping and general for humans who attempt in areas without infrastructure electricity. The standard can also be applied to other types of batteries and the current technology allows their development with much greater energy capacity.

Specifications of the prototype:

  • Battery 1.2v 700 mAh
  • Solar cell 1.5v 70mA

Solar self-rechargeable Battery – [Link]

Raspberry Pi Compact Camera

FFGMEUVI7KB9KMZ.MEDIUM

by PiJuice @ instructables.com:

I’m so excited about this new project! A truly compact and portable Raspberry Pi Camera and it’s easy as anything to build!

I first thought about building a Raspberry Pi Camera after seeing the SnapPiCam instructable guide. This is a clever little project, which uses a LiPo battery to power a Raspberry Pi model A. But it got me thinking could I do something even more compact which is even simpler to build?

The real challenge is powering this little baby. Where the SnapPiCam is using a separate battery, converter and charging unit I’ve used the PiJuice. It’s basically an all in one battery module for the Raspberry Pi and it’s an ideal integrated power solution for a DIY Compact Camera.

I’ve also decided to use the Raspberry Pi a+ as it’s the cheapest and smallest available Raspberry Pi so it’ll fit nicely with PiJuice and make this camera supper compact!

Raspberry Pi Compact Camera – [Link]

GPS Tracker for Alzheimer’s Patients

FGRIG3CI92LT354.MEDIUM

by LoganP2 @ instructables.com:

The GPS tracking device is composed of a microcontroller, GPS module, cell module, and batteries all housed in a 3D printed case. The microcontroller is programmed to communicate with both the cell module and GPS module. When the GPS module is not within a user-specified boundary, the device will send a text message alert. We made a device that can track people suffering from Alzheimer’s and Dementia could greatly benefit the quality of life of both that person suffering and the caretaker.

GPS Tracker for Alzheimer’s Patients – [Link]