Dilshan R Jayakody’s Web Log

Couple of months back we decided to create our own media server to store our MP3s and digital photographs. But it gets postpone several months due to unavailability of main-boards and other resources. Finally, after reviewing several prototypes we decided to build our media server using Banana Pi (BPI) and MiniDLNA . Before finalize BPI we checked several main-boards which including Raspberry Pi B+ , Orange Pi One and BeagleBone Black . Out of all above main-boards we choose BPI M1 because of its inbuilt SATA2.0 interface, Gigabit Ethernet port and availability in local market. Final view of DLNA media server setup. As an operating system we use Bananian Linux , which is Debian derivative for BPI platform. To sore all our content, we use Seagate 1TB SATA 3.5 inch hard disk drive. Bananian OS and other packages are loaded into 8GB SD card. To power both BPI and SATA disk drive we design PSU using LM2576-5.0 step-down switching regulator IC. Also during the prototyping sta...

This is 5V 3A power supply to drive two USB based devices simultaneously. This power supply is design around LM2576-5.0 switching regulator IC and the main reasons to choose this IC is its low parts count, small heat sink requirements and its inbuilt current limit protection feature. Prototype version of 3A USB power supply We specially design this power supply to work with development boards / single board computer (SBC) platforms such as Raspberry Pi , Banana Pi , BeagleBone , etc. This power supply can also be used to provide power to USB OTG peripherals over USB Y cables. We test this setup and got successful results with Huawei Ascend P6 mobile phone.

This is another configurable PIC microcontroller development board with E 2 PROM base storage and RS232 interface. Purpose of this development board is to emulate simple computation platform with storage, processing unit and control terminal. This development board contain LM2576-ADJ base 3A switching voltage regulator (with external power terminals), E 2 PROM base storage (AT24C04) with 512words × 8bit space and standard RS232 serial interface. All the peripherals of this development board can be isolated using onboard jumpers which include crystal oscillator, MCU reset line, E 2 PROM I 2 C interface and UART interface. This development board supports most of the 40pin 5V PIC microcontrollers which include PIC18F4550, PIC18F452, PIC18F4620, PIC16F877, PIC16F887, etc. Schematic diagram of this development board is available in Circuitbee with Creative Commons Attribution-ShareAlike 3.0 license.

In this post we introduce easy to build, full featured PIC16F877A/PIC16F887 microcontroller development board. This development board contains following core features: RS232 interface PS/2 host interface Battery backup - Real Time Clock with I2C interface Highly precision 1-wire thermometer interface 4 Digit Seven Segment Display module HD44780 compliant LCD module 4×4 Keyboard 4 button onboard joystick 8×2 LED driver 8bit peripheral driver interface 8bit Digital to Analog converter module 36kHz Photo module for Infrared base inputs Wide supply voltage range from 12V – 40V To reduce the form-factor we design this system in a double sided PCB. When constructing this project make sure to use exact component values for PSU module (especially for L1, R1 and R2). When constructing the circuit do not connect R4 and R5 wires to the PCB. Both these wire links are providing to isolate the PSU from main board. After constructing the circuit power on the PSU and check the v...