OVERVIEW
Nowadays we see oled display being used everywhere be it the phones , TVs , laptops or PCs , smartwatches . They sure are better than old chunky CRT TV displays that were bulky and didn’t deliver the desired picture quality , with the introduction of the LCD and backlight LEDs the things sure got better with the chunkiness of the display gone but the picture quality still wasn’t what one desired of but with the release of the OLED display all these problems became a thing of past. OLED or organic light emitting diode were invented in 1987 by Ching Tang and Steven Van Slyke from Kodak but it was until 2004 when SONY released a OLED TV. In fact in CES 2019 , there were some innovative inventions that were released in the OLED domain with the companies trying to come up with foldable display and some exceptional picture quality.
TYPES OF OLED
Passive Matrix Oled (PMOLED)
Pmoleds have strips of cathode , anode and organic layer. The anode strips are perpendicular to cathode strips it is their intersection that makes a pixel . External circuitry applies current to the cathode and anode strips to decide which pixel to light up. They are used in MP3 players , cell phones etc.
Active Matrix Oled(AMOLED)
Amoleds have full layer of anode and cathode and organic molecules . The anode layer overlaps the TFT matrix array . The TFT array is the matrix circuitry that decides which pixel gets turned on form the image. Since they consume less electricity they are used in TV screens , BillBoards, Computer Monitors.
Transparent Oled
A Transparent Oled has all the components cathode, anode, substrate transparent and when off the display is 85 percent transparent. When switched ON the display allows the transfer of light in both the directions.
Top Emitting Oled
The Top Emitting Oled is have substrate that is either opaque or transparent . They are best suited for active matrix design . They are used in smartcards
Foldable Oled
They are substrate that made of flexible metallic foil , plastic . They are durable and are easier to replace in case of damage . They are used in smart clothing , GPS receivers , IC computers.
White Oled
They are made of white light that is more uniform and energy efficient rather than fluorescent lights. They posses true color of incandescent lights
BESIDES THESE OLEDS ARE ALSO CATEGORIZED ON THE BASIS OF
- Monochrome Blue
- Monochrome white
- Yellow Colour
- 3 Pins (supports only I2C)
- 7 Pins(supports both I2C and SPI)
- SSD1306
- SSD1331
- 0.91 inch(128×32)
- 0.96 inch(128×64)
HOW OLEDs WORKS
- Both the LCD and OLED have similar display mechanism . The difference lies in the fact that OLED has the smallest display unit made of pixels that are usually 0.3mm x 0.3mm . Inside each pixel they are 3 different type of color filters . When the size of the color filter is reduced then human eye losses its ability to view each color individually and sees them as a mixture. Next each pixel is converted into digital form for future reproduction of the image.
- Earlier the image reproduction was done using backlight white , colour filters, glass , diffuser . When the light would glow each color filter would light up too. Behind the filters a polarizer lcd sheet is used which reproduces the image , the problem with this was the black colour produced wasn’t exactly black due to the back light being ON constantly .
- This issue was rectified using tiny light sources for each pixel due to which organic led was used . If we apply positive voltage to the anode termina the electrons would combine with the holes in the LUMO layer producing light. Work is also being done to remove the need for light source and add doping material in the emission layer which will release light of the certain color due to the energy difference in the conduction and valence layer corresponding to their wavelengths
FIG -1 SIZE OF A SINGLE PIXEL
FIG-2 RGB COLOR FILTERS INSIDE A PIXEL
FIG -3 CONVERTING EACH COLOR INTO BINARY
FIG -4 CROSS SECTION VIEW OF OLED
FIG-5 CHANGING THE ORIENTATION OF THE POLARIZER TO GENERATE DIFFERENT COLORS
FIG -6 ELECTRON HOLE PAIR COMBINATION TO GENERATE LIGHT
FIG – 7 DOPING OF SUBSTRATE TO GENERATE LIGHT OF VARIOUS WAVELENGTH
USE CASES OF OLED DISPLAY
HOW TO CONNECT THE DISPLAY WITH THE MICROCONTROLLER
WE WILL BE COVERING THE DETAILS ON HOW TO CREATE AN EMBEDDED DRIVER FOR THE DISPLAY IN THE NEXT BLOG . IN THIS WE’LL BE COVERING A BRIEF OVERVIEW OF THE 2 METHODS THAT CAN BE USED TO COMMUNICATE WITH THE DISPLAY.
Using I2C we’ll be communicating with the microcontroller by the help of SCL the clock pin that will keep the data transfer in synchronization and SDA the bus on which the data will be communicated.The speed in this case will be less but the no of pins required for communication is less and can be shared by other displays or sensors.
In SPI we’ll be communicating with the microcontroller using the pins CLK which is the clock input to the microcontroller . MOSI is used for displaying the data sent by microcontroller , Reset pin Resets the internal buffer of the OLED driver, DC this pin is used to separate the commands such as cursor position , clear screen from the data buffer, CS chip select is used to select the SSD1306 Oled display.
Automotive Microcontroller programming training session at DTU College
We have successfully conducted a 10-day training program on Automotive Microcontroller Programing at Delhi Technical University from 6th December to 15th December. The training program was attended by Btech Students of ECE branch and some students of Mtech branch. List of attendance as per dates are: 06/12/2024:25 07/12/2024:25 08/12/2024:23 09/12/2024:22 10/12/2024: Holiday by students 11/12/2024:23 12/12/2024: 22 13/12/2024:19 14/12/2024:15 15/12/2024:10 The 10 day training program session start by introducing students with the Microcontroller Technology. On day 1 of the training session students were made to taught microcontroller technology. General overview of what is semiconductor industry, how does semiconductor industry works and different kind of companies in semiconductor industry. Followed by in depth exploration of microcontroller technology, which is one of the kind of semiconductor chip. Diving into Building block, Functional block, Hardware Development Kit and Software Development Kit of Microcontroller Technology. In the end we conclude the day by discussing about Industrial Microcontroller like that of NXP, Renesas, Infenion giving students exposure to MCU’s apart from Arduino/ESP frameworks. We very much focus on NXP S32K144 MCU which is an automotive MCU and get handson feel with Its Development Board ElecronicsV3 and SDK of S32 Design Studio On Second day we followed by exploring and diving deep into automotive technologies. How Automotive Industry works, Different companies involved in it and overview of Automotive technologies like Functional Domain, E/E Architecture and Autosar Software Tech Stack. On this we very much deep dive into Autosar Software Tech stack and give stduents overview on how to start with it. We start by exploring the MCAL Layer technology of Autosar Software Tech Stack and set up its Software environment using S32 Design Studio IDE and its software package installation. On Day 3-4 we started with Handson experiment after getting initial overview of technologies. On Day 3 & 4 students explored the GPIO/PORT peripheral in Microcontroller technology, students were given in depth overview and understanding on how this peripheral works, why is it used, how to use it and its applications. Students were made to taught about this peripheral from Microcontroller datasheet and made to understand different specs/features of this peripheral from MCU documents. After that students were made to taught how to use this peripheral in Automotive Microcontroller by making them understand on its peripheral stack using Autosar MCAL Driver specs. Students were made to taught how to use Autosar Code configurator tool for GPIO/PORT peripheral. They were taught how to use Software API’s, what parameters to send on those API’s an in which chronology those API’s need to be used. In the end students were given time to learn and have Handson with Embedded Softwrae Debugging of microcontroller. They were made to develop different functional demo codes on GPIO/PORT peripheral and taught how to do embedded software debugging for it. Day 5 was holiday: After continous 4 days of technical learning and information, students asked for day off. Number of students on that day have interviews and assessments so day off on this day was taken. Day 6-7: we started with Handson experiment of ADC peripheral of microcontroller technology. We started by getting overview on what is ADC peripheral, how does it work, why is it needed and different specs/features of ADC peripheral in MCU’s. After that we deep dive into NXP S32K144 concentric ADC peripheral. We explored how ADC peripheral works in S32K144 MCU using its datasheet and exploring its peripheral register’s. After that students were made to taught how to use ADC peripheral in Automotive Microcontroller by making them understand on ADC peripheral Driver using Autosar MCAL Driver specs. Students were made to taught how to use Autosar Code configurator tool for ADC peripheral. Understanding and exploring its different menu sections, sub menu sections. Which sections to configure, how to configure and why to configure. They were taught how to use Software API’s of ADC Driver stack, what parameters to send on those API’s an in which chronology those API’s need to be used. In the end students were given time to learn and have Handson with Embedded Softwrae Debugging of microcontroller for ADC Peripheral. They were made to develop simple functional demo codes of reading POT values using ADC peripheral and taught how to do embedded software debugging for it. Day 8-9: On these 2 days students were made to taught PWM Peripheral of Microcontroller technology. How PWM signals are generated, how they work , different sepcs/features of PWM Signals. Students were made to introduce the concept of TIMER peripheral in MCU’s which is used to generate PWM signals via it. In these 2 days students were also made to get familarize with Logic Analzer tool which is used to capture PWM Signals. Students were made to understand TIMER peripheral of NXP S32K144 Automotive MCU, how it works and how to use it for generating PWM signals. Followed by theory and hardware overview of PWM signals, students were made to do Handson exploration by generating PWM signals of different frequency/duty cycle using PWM Driver stack of Autosar MCAL Layer. After that students were made to taught how to use TIMER peripheral in Automotive Microcontroller by making them understand on PWM peripheral Driver using Autosar MCAL Driver specs. Students were made to taught how to use Autosar Code configurator tool for PWM Driver. Understanding and exploring its different menu sections, sub menu sections. Which sections to configure, how to configure and why to configure. They were taught how to use Software API’s of PWM Driver stack, what parameters to send on those API’s an in which chronology those API’s need to be used. In the end students were given tasks to generate PWM signals of different frequencies and duty cycle. On the last day, students were instructed to do Integration of What all thinsg they have learned so far. They were given task to Combine all Peripheral of Automotive MCU which was taught as if now in a single project. They did a task of using GPIO, PORT, ADC & PWM Peripherals
SPI Peripheral in S32K144
Explore this blog to know about SPI peripheral in NXP S32K144 MCU
UART Peripheral in Microcontroller
Explore this blog to know about UART peripheral in Microcontroller for doing UART communication
SPI Communication in Microcontrollers
Explore this blog to know about SPI peripheral in Microcontroller for doing SPI communication
TIMER Peripheral in Microcontroller’s
Explore basics of TIMER Peripheral in Microcontroller!!
ADC Peripheral in Microcontroller’s
Explore about ADC peripheral in Microcontroller from foundational and functional level
Author: Kunal Gupta
