Turn-key PCB assembly services in prototype quantities or low-volume to mid-volume production runs

The Tiny and Powerful Frequency Counter

How often you get involved with the frequency counter? Do you know that the frequency counter is designed for radio frequencies (RF) are common and operate on the same principles as lower frequency counters did? Normally, they have more range before they overflow and for very high frequencies, many designs are use a high-speed prescaler to bring the signal frequency down to a point, where normal digital circuitry can be operated. The frequency counter that you’re about to build here is a basic and low cost frequency counter circuit, where it can measure from 16Hz to 100Hz signals with a maximum amplitude of 15V. The sensitivity is very high and the resolution is 0.01Hz. For the input signal, it can be a sine, a square or a triangle waveform! The accuracy of a frequency counter is strongly dependent on the stability of its time base. Those highly accurate circuits are normally used to generate this for instrumentation purposes, and it is usually using a quartz crystal oscillator within a sealed temperature-controlled chamber known as crystal oven or Oven controlled crystal… Continue reading

Interfacing RFM12 transceiver module

RFM12 is a transmitter and receiver module in single board. It can be powered by using 2.2V to 5.4. it makes ideal module for embedded systems. Module communicates via SPI interface.   Wigbert Picht and Dirk Milewski have made simple Atmega8 tesboard, where RFM12 module is soldered as SMD element and can be configured with jumpers. There can be any sensors connected to this board like temperature. Schematic and sample Bascom AVR program are available for download. Continue reading

RF mail messenger

Is your mailbox standing away from your house? Maybe you would like to know exactly when mail arrives? No problem at all. The guy called newbie123 in AVRfreaks have build a nice system which rings a buzzer when mailbox is opened.   System consist of two parts. Transmitter and receiver. Both parts are controlled by AT90S2313 AVR microcontroller, that can be easily replaced by Attiny2313. Messenger uses the TLP434A transmitter and the RLP434A receiver from SparkFun. The transmitter is mounted inside a small plastic radio shack box. Transmitter is placed at the back of the mailbox so it does not interfere with anything. The antenna is routed down through the bottom and just sticks down under the mailbox. When the mail man opens the door to the mailbox, the ground wire is connected to the circuit and the transmitter powers up, transmitting the 4 byte packet to the receiver mounted inside the house. Cool Toy. Continue reading