#pic16f88

[jayakody2000lk]

This post describes our initial attempt to design an automatic Zener diode tester. This tester is designed using well-known ICs such as MC34063 and PIC16F88.

This unit is capable of identifying Zener diodes up to 27.5V. Apart from that, it can be used to recognize leads of the diodes/Zeners and detect damaged diodes.

For this project, we use components that are already in our inventory. Most of these components can be replaced with more accurate and modern substitutes.

This unit provides approximately 5% to 15% accurate readings. Based on our observations, the accuracy of this unit can increase by using resistors with 1% tolerance, stable booster circuit, accurate sampling method(s), and with a more optimized PCB layout.

The schematic, PCB design and firmware of this project are available to download at github.com.

[jayakody2000lk]

If you are an audio enthusiast and if you have multiple audio systems and speakers, you may definitely need to have a speaker selector switch. These switches allow you to route a audio signal through a switching system and distribute it to various speakers. Using this listener can select single amplifier – speaker combination through the switch. We mainly design this switch to share our speaker system with multiple audio amplifiers. We design this switch to handle 6 stereo audio channels.

This switch is based on PIC16F88 – 8bit MCU, ULN2803 Darlington transistor arrays and 12 DPCO relays. MCU is the core component of this switch and it control all relays, seven-segment display and store last channel in E2PROM memory and restore it during next power-up.

This speaker selector is an open hardware project, all it’s source codes and schematics are available to download at google drive and github.com. All it’s content are released under the terms of MIT and CC BY-SA licenses.