Saturday, March 25, 2017

E-Ink Table Clock and indoor ,Outdoor Temperatur Monitor With PIC32MX

This is an follow up For the previous post in which i demonstrated how you can drive kindle E-ink display with a microcontroller. 

previously i was using a MSP430FR5739 , which is really low power mcu but has very little RAM and a bit low speed to do anything related graphical on it.E-ink has 800x600 pixel resolution so it required minimum 60Kbyte of RAM to store Frame Buffer. although you can easily getaway without frame buffer by directly doing incremental drawing on to screen but there are few issue in that because of the way E-ink display works. one more issue with there with MSP430 , it has very low program memory so we need some sort of external memory to store font data and icons. 

so i have decided to use PIC32 microcontroller , PIC32MX795F512H to be exact. which has enough of ram and flash  can go up to 80Mhz. which is more than enough for our purposes. 

Thursday, March 16, 2017

Simple Kindle E-ink Display Driver with MSP430

i have trying to get Kindle 6 inch e-ink display to work with Microcontroller quite some time because i really like the way e-ink display looks. Although many people have done it before but for some reasons there code was not working for me.  i have already tired with a my WireFrame FPGA Board but failed for unknown reason.  So i decided to give it try i designed a new board to give it Second Shot and i finally managed to get it "work" . this time i am using MSP430FR5739 microcontroller for no particular reason. i just needed a part so i used MSP430FR5739 Because i have used this before in my solar LED project.

This this just quick demo of concept to test if i got waveforms right. as MSP430FR5739 is quite slow and does have only 1KB of sram ,Controlling a 800x600 pixel display is really  pain. so i will use some powerfull microcontroller to display rich graphical content on this display.

Sunday, March 5, 2017

Low Power Outdoor Wireless Temperature Sensor with MSP430 NRF24F01+ DS18B20 , 6 month Battery Life on Single 1200mAh li-Ion

In this post i am going to quickly describe , how to make really low power Wireless Temperature sensor for Outdoor Temperatur Monitoring. Though in this demonstration i am only having Temperature sensor but in theory you can have any type of sensor connected to processor and get in transmitted over RF.

Monday, November 7, 2016

Smallest Audio Spectrum analyzer "TI TMS320 DSP FFT Implementation" 96x16 OLED display

In this quick little demo i will show you real time 256 point audio band spectrum analyzer, i will be using ezdsp5502 board , which has TMS320VC5502 and for input signal sampling we are using onboard audio codec TLV320AIC3204B to sample input signal at 48Khz sampling rate. its  post is not going to be tutorial for FFT , the scope of this post is only to show how to get contentious input sampling ,FFT calculation and display on the little FFT Display.
with 48khz sampling  256 point FFT, we can see up to 22Khz singal in our 128 point FFT result ,  with resolution of 171 Hz for output point each point.

Monday, October 31, 2016

Moving average Digital Filter implementation TI TMS320 DSP

In post , i am going to show you how to implement the simplest possible digital filter "moving average filter". though it is very easy to implement but still in many applications this is more than good enough. for example reducing random noise from signal. ofcourse when it is very simple it does have issues like , it does no have very sharp filter Response.
Channel 1 input , sweep from 20Hz to 6Khz, Channel 4(Green) 15 point filtered output, M (Red) output in freq domain

Saturday, October 1, 2016

Solar LED Light ,20000mah Li-ion battery , 24V solar panel with MPPT charge Controller

This project is the final part in Making a really powerful Solar Light , in this project we intigrate LTC3478 Based philips lumileds Driver and BQ24650 Based MPPT Solar Li-Ion charge Controller.
We will be using total 3 9 Watt each LED Driver boards and One charge controller to charge 6 Cell 7.6V 20000mah li-lion battery,

There is 4 LED bar graph display to show estimate battery level and a single button to control On/off, Different Level of Brightness , and Select one , all or few of LED boards to litup.
there is not much to describe in term of schmeatic and firmware as all the Firmware and Schmeatic aer already on my github account.User interface panel is made out of PCB with 4 battery status LED a port for solar panel Connector and a control switch.
when battery is chargin LED status displayed accordingly and when battery is discharging led status updated accordingly.

Friday, September 30, 2016

BQ24650 Based MPPT li-ion Battery Charger Controller With MSP430 Microcontroller, MPPT adjust and 3 Channel LED PWM dimming.

In the addition to the little solar lighting project that i was working on i have created this little solar charge controller to charge lithium ion battery (li-ion).

Circuit Utilize Texas Instrument BQ24650 at the heart of loop to control charge. as circuit has external mosfet so maximum  charge current can be adjusted to really high values.  Circuit accept Solar Panel Values from 5V to 28V . i have tested it with 12V nominal (17Volts open circuit)  . and 24 Volts nominal Solar panel at Battery Charge current up to 4A. Currently installed in my house since few months Charging a 20000 mah li-ion battery.
Circuit has large 4 pin high current capacity Molex connector for solar panel , 6 pin connector for Battery and load switch.
it is also possible to connect NTC for battery temprature monitoring. BQ24650 can automaticalley monitor temprature of the battery. Microcontroller has dedicated 3 PWM output for LED dimming and 6 gpio pin header for bettery status led and a user interface key.