The Compact-Sized Zero Pin Loader

Zero Pin Loader, do you have any idea what this stuff for? To be honest, some of you here might haven’t hear or use it before. Actually, the Zero Pin Loader is a bootloader for the PICmicro 18F series. Its main function is to avoid the use of I/O pins, by simply exploiting the /MCLR pin as the only interface between the host PC and the PICmicro. It uses the PIC16F877 microcontroller as the main part, where is having the ability to write to their own code memory. The Zero Pin Loader is unique, as the interface between the PC serial port and the target uses six components! The standard /MCLR is one of the six components. The interface circuit can be put in a common DB9 shell and with a DIP clip for the connection to the target. There’s some downfall for this Zero Pin Loader and you have to get it solved. Most of the development environments have the transparent bootloader, but the limitation being that the highest 384 instructions are not available to the application. Hence, you… Continue reading

The LM317 Regulator Mini Lighthouse LED Circuit

Do you know why this project named as “Mini Lighthouse LED circuit”? It’s because the LED circuit has a shape like a lighthouse and that’s the reason it got the name here! Basically, this is a simple “lighthouse” that when it’s powered up, it will rotate the beam around the 12 LEDs. This Mini Lighthouse LED Circuit is a very useful tool, especially for a model railway. For your information, this Lighthouse has several interesting features. The first feature is a full size ICSP connector, while the second is a socketed DIP version of the PIC12F683. Those 12LEDs is the maximum numbers of you can charlieplex from four tri-state pins. The PIC12F683 is an eight pin device that has five GPIO plus the MCLR pin, where it can be used as an input. You can keep one GPIO spare, GPIO four where it also happens to be an analog port that allow you to add a light sensor that turns the lighthouse on when it gets dark. Furthermore, this version has an LM317 regulator on the back so it can… Continue reading