Monthly Archives: February 2013
This project is an Application/extension of Digital Pulse Counter.
Transmitter Part: The transmitter circuit (see Fig. 1) is built around timer NE555 (IC1), which is wired as an astable multivibrator producing a frequency of about 38 kHz. The infrared (IR) beam is transmitted through IR LED1.
HERE A is +9V and B is GND.
Receiver Part: There are two 7 segment displays driven by two CD4026B (CMOS DECADE COUNTER/DIVIDER) used here to count up to 99. Seven Segment display used are common cathode type(see fig below).
Moving ahead when the transmitted signal is cut, Pulses are generated by the IR receiver TSOP1738. The output of TSOP1738 is then fed to monostable multivibrator circuit made using NE555. Then the controlled stable pulse of 250ms (T=1.1*R*C) is fed to CD4026B which will drive the unit place display to make it count from 0 to 9. When it overflows, carry is generated by this IC and this carryout is fed to another CD4026B driving Tens Place display . Thus making the whole circuit count 0 to 99. Similar CD4026 circuit can be added to increase the number of counts.
This Circuit has various applications such as spring oscillation counting, Counting no of people entering through door(one way), as a bugular alarm, etc.
Here you can download the PDF Schematic of the receiver part.
Finally! The news that Nokia has decided to cut the apron strings from its beloved Symbian OS just was a long time coming. It seemed like Nokia was simply flogging a dead horse, expecting it to go faster. It had its run, it survived this long and that’s something in itself. The time to let go was, well, a long time ago.
It is great news to hear that Nokia is finally putting the Symbian OS to rest. This was simply some baggage that needed to be shrugged off in a hurry. For any Nokia fan it’s great to see it picking itself up, dusting itself off and donning a new avatar with Windows Phone, all in a bid to re-establish itself as a major player in the market. What I find truly heartening is that it’s taking the best of the old ideas, updating them and incorporating them into its new products. This is what it should have done a long time ago, but as the cliché goes, better late than never. Anyway, no one was really looking forward to the next Nokia Symbian handset, but I know, I’m looking forward to the next Nokia Windows Phone.
Symbian was just not the OS it used to be. Belle or Anna might have brought some measure of innovation to the ailing operating system, but it was never enough to tear the crowds away from the Android and iOS. With dwindling market share, it was dying a slow and dreary death.
Nokia’s focus should now be a little more streamlined in terms of what it wants to achieve from the mobile OS market. If it’s going to stick to Windows Phone as a primary OS, then it should push the developer community to start taking more interest. That being said, Nokia’s efforts have been valiant and it’s time now to see a whole new Nokia.
The time has come to say goodbye
Symbian served us well. It was my first love with the mobile phone, the jazzy colours, cool icons, smart functions—it was what ushered in the age of smartphones. Nokia has always had plenty to offer, but for some reason, there seemed to have been some hiatus in Nokia’s think tank and as a consequence, Symbian’s evolution remained relatively stagnant with only a few minor tweaks incorporated over the last couple of years. The mobile OS got smarter and Nokia, for some reason, chose to stay in the past.
While it got our attention by adding a few relevant technologies to the great hardware and trying desperately to push the OS as far as it would go, the hook was never the OS. Devices like the E7 Communicator or the Nokia N8and PureView 808 were great innovations, but only in distinct and specific features like design, hardware and, of course, their cameras. However, the complete package was just not good enough. We’ll never forget the handsets and will probably still compare them to some of the new devices whenever they try and up the specs, but all we’ll really be talking about is the camera and design again. But any such comparison or discussion gets derailed the moment we start talking of the operating system.
So, we finally bid adieu to the OS that got the ball rolling. Symbian, you showed others the way and will always be rembered as the pioneer, as far as I’m concerned, but it’s time we let go and move on. We salute you as we say goodbye.