Prescaller devide by 10 with IC CMOS 74HCT390

By using IC CMOS 74HCT390 we can make the cheap prescaller.
Datasheet IC can download here.

Figure above is 74HCT390 logic symbol

This Prescaller I have tried and use the Frequency counters that measure the ability for HF Frequency counter (0-30MHz) can also be used to measure the frequency VHF (30-300MHz).
To measure the small signal circuit will be added buffer / pre-amp before the signal is inserted into prescaller.
Design construction can use PCB assembly or perforated with ugly style that all these prescaller circuit can be added to the box Freq counter and switches can be added to the measurement of the input frequency HF or VHF.
Need to be careful in the construction, make sure the connection is especially true in the provision of the CMOS voltage must be stable 5V. I've ruined this IC because there is over-voltage.

An Autonomous Wheeled Climbing Robot

An innovative off-road wheeled mobile robot ,named Octopus, able to deal autonomously with obstacles in rough terrain without getting stuck. To achieve such a perfomance. the robot is equipped with tilt sensors and tactile wheels. The sophisticated locomotion mechanism of octopus has 8 motorized wheels and a total of 15 degrees of freedom (14 of them are motorized).
A two dimentional static model and a controller are proposed. The inputs of the controller are the contact points with ground, the geometric angles of the articulations, and the direction of the gravity field. The output of the controller are the torquest for the wheels, the torques for forearms, and the position set point for the body. For read more see here

Homebrew 30Mhz Frequency Counter

Design tools that I created is based on an amateur radio OM3CPH, the site he was actually there are 2 kind of design are Seven segment display and LCD display. To save money so I select the design that using Seven segment display.
Construction: For Schematic, PCB and PIC source programs I use OM3CPH original design or can download here , for the power supply is very easy to make that could provided a stable 5V voltage to the PIC microcontroller, for box case can be made according to our tastes, of this I use acrilig formed sheet and the box cover use material from PCB sheet. Front panel of the box we can print with our personalizing , printing is made by computer and I stick with double-sided tape.



Peripheral: For the purposes of measurement must have a suitable probe, using probes with a length of cable as needed. To probe Conector ground used for the crocodile and measuring probes use the osiloscope probe but with a cheaper version.
Have Fun...

How to Interface a Microchip PIC MCU with a hobby R/C Servo

Servo motors can be used with success in several different robotic applications. The have a very simple electrical interface and are available in a great assortment of specifications and prices. Usually one can get started with a very cheap one. This paper will show how to control one of these servos using a PC and a microchip PIC microcontroller. For read more see here.