Forget about Weak Signal with Mobile Phone Signal Booster

Have you ever had the situations in the office when you desperately needed to call your client and agree on a deal, but your mobile phone kept breaking saying that there was not connection?

The Old Story of the Old World

The story when people complain that their mobile phone is always out of coverage is not new and quite typical all over the world.

This very problem is rather painful for workers whose work efficiency depends on calls.

Unfortunately, it can be a typical problem of many multistoried building, where most office plankton works. Continue reading


How hard can it be to build Linux mini computer

Today this is not a problem to get a Linux based development board really cheap. Raspberry Pi or Beagle Bone are the first that come to mind. Having those on your desk you wouldn’t think about building one by yourself. Unless you want to challenge yourself. Henrik thought it would be fun to build a Linux board with BGA processor. We all know that soldering BGA at home can be tricky, but doable. So he’s chosen cheap ARM processor with memory management – AT91SAM9N12. It comes in 217 BGA package with 0.4mm balls and distance between 0.8mm. Next to it he added DDR2 RAM which also comes in BGA package.


Another challenge was to find PCB manufacturer which would make small pads and vias reliable and cheap. OSH Park seemed to be right choice. Once boards has arrived, next step was to solder chips and other SMT parts. He applied soldering paste with stencils and placed chips. He had to be careful because even 0.4mm error would cause row offset of ball array. Obviously soldering was done with reflow oven which did job pretty good. Other components like NAND flash and large components were soldered by hand. Then he configures Linux system which had to be loaded in to memory and magical screen appeared. This is amazing what can be done with home conditions and some knowledge today.


Product Design Services

Many times people have ideas in their head for a unique or even revolutionary product that has never been and have dreams of producing and selling the item, or even trying to license the idea to another company to produce.  There are many steps along the way when going from an idea in one’s head then a rough sketch on the back of a napkin to making a commercially viable product.  To bring an idea to market, the idea needs to be protected, the design refined and developed to be manufacturable, and then produced and marketed.

The first step with any idea is to address any intellectual property concerns.  For most products, the first step is to do a patent search to see if there is any existing intellectual property.  If the product is to be sold in the United States, the United States Patent Trademark Office is the first place to start.  There is a search function available at  If there is no evidence of an existing patent then the new idea should be protected via the patent process.  This can be very complex and is outside of the scope of this article.  If budget allows, it is best to consult an attorney or other legal professional that has expertise with intellectual property. Continue reading


Testing stepper motors with pulse generator

This is a quick portable circuit used to test stepper motors. It is based on small PIC 12f675 microcontroller. The pulse speed is changed with potentiometer. It allows smoothly variate between 20Hz and 3kHz.


It has couple jumper bridges to select enable and dir pins. Servo tester is powered with four NiMh rechargeable batteries that give total 4.8V.  This circuit can also be used as general purpose pulse generator if needed.