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23 Jun 2015

obr1719_uvod

A possibility to read an RFID card even on a longer distance is usually highly appreciated at its everyday usage.

As we know, RFID module range is expressively depending on a size and shape of the RFID antenna (coil). That´s why the module with a big antenna has a potentially bigger chance to reach a long range. This is exactly a case of the ID3LA module – working in a wider operating voltages range (2,8-5V) than its predecessor – the ID2 module. This enables its usage even with a 3.3V logic and also for example in battery-operated devices (3-4x NiMH, or 1x Lithium cell, …) not requiring DC converters or a precise voltage regulation.

ID3LA belongs to the „ID3/ID12/ID20“ family with very similar electrical parameters and a way of usage. All modules of this family function as readers sending data – a unique ID of a given RFID tag. The most favourite type – ID12(LA) has a very decent range (approx.. 12cm) sufficient for majority of applications. However, if the space in your application allows you to use ID3LA, you´ll reach a significantly longer range. ID3LA requires an external antenna – included in the package, as illustrated on the attached pictures.

Detailed information will provide you the ID3LA datasheet.


With the ID3LA RFID module it´s possible to read a tag up to 30cm – [Link]

16 Jun 2015

obr1715_uvod

Modern spread spectrum modulation enables HopeRF LoRa modules to communicate on a long distance or in severe environment.

Extraordinary price-attractive modules from company HOPERF Micro-electronics specializing to RF modules and a wireless signal transmission were introduced to you in our article HOPERF – universal RF modules for surprising prices.This time we come with a novelty – module RFM95SW with a „LoRa“ suffix, indicating membership with a „Long Range“ family of modules. Long range of HopeRF LoRa modules is reached by usage of a modern efficient modulation with a spread spectrum, able to transmit data even on a noise floor level. RFM95W solves a traditional compromise among range, immunity (selectivity) and a power consumption while conforming to limits for usage in free bands.

LoRa modulation is quite complex and a user has a possibility to adjust all three main modulation parameters in order to fully meet requirements of a given application. These parameters are spreading factor, modulation bandwidth and error coding rate. For example if don´t need maximum transmission speed, we can set parameters so as to gain the highest possible quality and reliability of connection. By setting these three parameters we can choose an optimal combination for a given application.

RFM95W is ideal for OEM products with higher production series, where development costs usually get quickly refund also thanks to a very affordable price of these modules.

Detailed information will provide you the RFM95SW datasheet. To make a development easier, the RFDK_RFMxx starter kit is also available (upon order).


LoRa = RF modules with a long range – [Link]

26 May 2015

IMG_20150525_190458536-600x436

Marcus Jenkins blogged about his radio frequency amplifier project:

In building QRP HF radios, having an RF signal level amplifier building block is handy. You want 50 Ohm output impedance, some reasonable gain, supply voltage of the usual 10-14V and ease of building using standard parts from your parts bin. Some searching around the interwebs came up with a good idea for circuit from Aaron Parks, KC8FQD, who did a YouTube video on a WWV receiver.

A signal amplifier module for HF – [Link]

25 May 2015

obr1706_1

High mechanical stability is one of benefits of a new „SMT“ version of the popular Lantronix xPico WiFi module.

Lantronix xPico WiFi module may be already familiar to you from our articles, for example: xPico WiFi is a dream come true for producers and customers where we also mention the HW compatibility with the xPico module ( wired, serial-to-Ethernet modul). New version – xPico WiFi SMT brings the same functionality as xPico WiFi and as the name saysm it´s intended for a direct soldering by an SMT (reflow) process, together with other components on a PCB. In contrast to original version which has an SMT (board-to-board) connector, SMT version is designed similarly like many GSM/GPS modules, i.e. as a module on a carrying PCB with soldering pads on PCB sides (half-vias, plus gnd on a bottom).

At the same time, SMT version is also available with integrated small ceramic antenna, so no external antenna is required. Just this version XPCW1003100B we keep as a standard stock item. Perhaps the biggest advantage of SMT version is this possibility of a direct soldering bringing a very high mechanical stability – also suitable for applications with a higher risk of vibrations.

xPico WiFi SMT is the same powerful („device server“) as a previous version and offers easiest way how to add WiFi connectivity into a target device, practically without a necessity to write a single line of code.

Simultaneous AP (Access Point) with a DHCP server and Client mode also enable a direct access – communication with other WiFi device, for example with a tablet or a smartphone.

Detailed information will provide you the xPico WiFi SMT brochure, xPico WiFi SMTi datasheet and the xPico WiFi SMT integration guide.


xPico WiFi SMT doesn’t require connector neither antenna – [Link]


19 May 2015

In digital electronics, fan-out is defined as the number of gate inputs that the output of a single logic gate can feed. It is very important in digital systems for a single logic gate to drive other gates or devices. In this case, a buffer can be used between the logic gate and the devices it will drive. Clock buffer is also called as fan-out buffer. The IDT clock buffer clock divider and clock multiplexer portfolio includes devices with up to 27 outputs. Differential outputs such as LVPECL, LVDS, HCSL, CML, HSTL, as well as selectable outputs, are supported for output frequencies up to 3.2 GHz and single-ended LVCMOS outputs for frequencies up to 350MHz.

Modern digital systems often require many high quality clocks at logic levels that are different from the logic level of the clock source. Extra buffering may be required to guarantee accurate distribution to other circuit components without loss of integrity. Many systems require low jitter multiple system clocks for mixed signal processing and timing. The circuit shown in interfaces the ADF4351 integrated phase-locked loop (PLL) and voltage-controlled oscillator (VCO) to the ADCLK948, which provides up to eight low voltage differential signaling (LVDS) outputs from one differential output of the IDT 8SLVD1208-33. The IDT8SLVD1208-33I is characterized to operate from a 3.3V power supply. Guaranteed output-to-output and part-to-part skew characteristics make the IDT8SLVD1208-33I ideal for those clock distribution applications demanding well-defined performance and repeatability. Two selectable differential inputs and eight low skew outputs are available. The integrated bias voltage reference enables easy interfacing of single-ended signals to the device inputs. The device is optimized for low power consumption and low additive phase noise.

Fan-out buffers and clock dividers are general-purpose clock building block devices that can be used in any number of applications. They are ideal for clock and signal distribution in a large variety of systems, from personal computers to consumer electronics or industrial systems, as well as high-performance networking and communications systems.

Increasing Outputs from a Clock Source – [Link]

14 May 2015

LDMOS

Nowadays, laterally diffused metal oxide semiconductor (LDMOS) transistors are widely used for RF Power Amplification and in many applications. A simplified circuit of an LDMOS amplifier bias circuit is shown in the schematic diagram above. The DC Bias on these amplifiers is set by applying a DC voltage to the gate (VGS) and by monitoring the Drain current (IDD). Ideally, this IDD will be constant over temperature, but since the VGS of LDMOS amplifier devices varies with temperature, some type of temperature compensation is required.

The ISL21400 features a precision voltage reference combined with a temperature sensor whose output voltage varies linearly with temperature. The precision 1.20V reference has a very low temperature coefficient, and its output voltage is scaled by an internal DAC (VREF) to produce a temperature stable output voltage that is programmable from 0V to 1.20V. The output voltage from the temperature sensor (VTS) is summed with VREF to produce a temperature dependent output voltage. The maximum voltage supply of the ISL21400 is 5.5V, and the LP2950 voltage regulator drops the LDMOS voltage to 5.5V for the ISL21400 supply. An LC filter is then added to the output of the voltage regulator to ensure no RF energy present on the supply line. The ISL21400 can be tied to a microcontroller or to any I/O connector for PC control and programming.

The RFPA bias control using the ISL21400 is very straightforward. The RFPA uses the Freescale AFT21S140W02GSR3. LDMOS are useful devices for many applications including commercial FM broadcasting and TV power transmitters, cellular and paging communication systems, and military RF and microwave hand-held transceivers.

LDMOS Transistor Bias Control in RF Power Amplifiers – [Link]

21 Apr 2015

CypressEZ-BLEPRoC

by elektor.com:

Following on from the release of their PSoC 4 BLE chip at the Electronica Exhibition last year, Cypress Semiconductor Corp are extending their play in the Bluetooth market with the introduction of their new EZ-BLE module. The module contains the PSoC 4 BLE chip together with two crystals, an on-board chip antenna, RF shielding and passive components, all in a compact 10 mm x 10 mm x 1.8 mm form factor so that designers using the module can apply to add the Bluetooth logo on their products by referring to Cypress’s Qualification Design Identification (QDID) 67366, a unique serial number assigned by the Bluetooth SIG. The module is compliant with wireless regulatory standards in the U.S., Canada, Japan, Korea and Europe and offers a significant saving for designers in development, testing and certification costs.

Cypress Bluetooth Module – [Link]

26 Mar 2015

IMG_20150326_09360122-600x450

Martin writes:

The rumors for RFM12B’s end-of-life two years ago seem to have been highly exaggerated now and the popular RF module is still available in abundance. HopeRF has introduced a pin-compatible upgrade, the RFM69CW. The module itself offers improved sensitivity and range compared to the RFM12B (+30%) at the cost of increased power consumption, making it probably a good choice for the receiving end (RFM2Pi), and probably less suited for low power battery operated nodes. The new module supports RSSI for those interested in measuring it.

The new module is more power hungry, and simply replacing a RFM12B on the RFM2Pi v2 or a Funky v3 with it didn’t work; The boards browned out so I had to swap C4 and C7 on the RFM2Pi with 10uF caps and populate the 0805 10uF on Funky v3’s boost regulator circuitry to get it to work. I’ll ship the boards with these refinements from now on so that they are compatible with both the RFM12B and RFM69CW.

[via]

Using RFM69CW instead of RFM12B – [Link]

17 Mar 2015

In this video Craig demonstrates his custom DIY RFID smart lock project:

The goal of this project was to design an inexpensive rfid door lock which could be opened via smart phone, and have all activity logged w/o utilizing any 3rd party servers or cloud hosting.

Custom DIY RFID smart lock – [Link]

14 Mar 2015

microchipRN2483

Microchip Technology Inc., has announced the first in a series of modules for the LoRa technology low-data-rate wireless networking standard. The system is designed to allow Internet of Things (IoT) and Machine-to-Machine (M2M) wireless communication offering a range of more than 10 miles (suburban), a battery life of greater than 10 years, and the ability to connect millions of wireless sensor nodes to LoRa technology gateways. The 433/868 MHz RN2483 is a European R&TTE Directive Assessed Radio Module measuring 17.8 x 26.3 x 3 mm and with 14 GPIOs to provide connections and control for a large number of sensors and actuators.

The RN2483 is also supplied with the LoRaWAN™ protocol stack, allowing connection with the LoRa Alliance infrastructure—including both privately managed local area networks (LANs) and telecom-operated public networks—to create Low Power Wide Area Networks (LPWANs) with nationwide coverage. This stack integration also enables the module to be used with any microcontroller with a UART interface. The RN2483 also uses Microchip’s simple ASCII command interface for easy configuration and control.

Microchip LoRa Network Module – [Link]



 
 
 

 

 

 

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