Friday, January 23, 2015

TLV320AIC23B Audio Codec Breakout Board

to get audio capability to my Raspberry pi / beaglebone / Aduio DSP(TMS320) projects i found my self making this little breakout board i hope you find useful.

PIC18F14K50 USB Breakout Board with RS232

 quite a some time ago i worked on this little pcb for PIC18F14K50 microcontroller , the good thing about this microcontroller is that it has  USB capability so i did this tiny pcb to utilize USB. the board made out of two kid of separate  sections as shown in the 3D rending blow, you can use this board a proper USB to RS232 converter or cut through the black line and it become simple USB I/O board.

Tuesday, January 6, 2015

12 Channel Relay + 2 Channel Dimmer control by IR Remote and keyboard

as extension to IR(infrared) Remote Control Relay Board with PIC 12F675 Microcontroller i have done this quite a useful project after too many requests. by using this hardware user have option to turn up to 12 relay on and off and two loads (like fan or motor) can be controlled with adjustable speed in case of motor , or adjustable intensity in case of a bulb.

this project is directly involved with high voltage AC which may cause sever damage. proceed with caution.
i will not be responsible for any risk involved,  you are on you own.

IR protocol 

IR protocol is same as previous projects . we use NEC protocol please refer to this link to know more about NEC protocol


Friday, January 2, 2015

Measuring True RMS Mains Voltage and Frequency using MSP430 microcontroller

To practice DSP algorithm on MSP430 microcontroller, i am working on a project "Mains Monitor" which is basically a spectrum analyser which will monitor AC mains voltage using Fast Fourier Transform (FFT) and show spectrum frequency domain on a graphical LCD , the spectrum can be used to view if any harmonics present in the mains voltage which will ultimately determines the quality of the supply.

measuring True RMS voltage and frequency is part of that project, alongside of spectrum the LCD screen will display True RMS Voltage and frequency of AC mains line. most of the normal AC mains voltage meter measure average/peak voltage and then adjust the voltage a little considering sine wave input waveform. average measurement technique works well till input is pure sine wave but as soon as you input other waveform  like square wave from backup UPS, normal meter will not read them correctly. so if you want real effective voltage level you have to calculate true RMS voltage. but calculating true RMS is not very easy it need a decent amount of calculation to be performed. small microcontroller are not generally meant for these calculation but MSP430 is mixed signal microcontroller , it has few very advanced peripherals to support some light weight DSP operations. we will see in a minute how to calculate True RMS of a signal and what are the challenges doing this on a small microcontroller.