So, the Texas Instrument’s Summer Internship Workshop on Embedded Product Design began with great gusto this season and an overwhelming response for both the MSP430 and the BeagleBone Black platforms. The day commenced with registrations followed by photo clicking of each participant for ID card purposes and backpack distributions along with the components and tools kit. The participants assembled in the auditorium and the event was formally kick started by Electronic Lamp lighting ceremony. (A project patented by CEDT, NSIT)
Inauguration using Electronic Lamp
Professor Dhananjay V. Gadre, Director TI CEPD, NSIT briefed the audience about the internship program and Centre for Electronic Design and Technology (CEDT) Laboratory at NSIT followed by introduction of eminent Professors, Dr. Raj Senani and Dr. Tarun Kumar Rawat. Dr. C. P. Ravikumar, Director ,Technical Talent Development at Texas Instruments, India also had a small session with the audience wherein he gave a briefing about Texas Instruments and how it has evolved over the years. The session here broke for tea post which, Dr. Ravikumar again took the stage to discuss the commercial applications and feasibility of embedded products such as the Electronic Lamp itself. This was followed by demonstration of various completed projects at CEDT, an exercise that saw keen attention from the participants as they watched the projects work flawlessly. The session then broke for lunch at 1pm succeeding which Professor Gadre commenced Talk 1 wherein he gave an overview of the Embedded Systems and some typical applications.
Dr. C. P. Ravikumar briefing the participants
Esteemed professors of NSIT gracing the ocassion
CEDT/TI-CEPD Projects Description
- Battery less TV Remote: A remote which does not require batteries. It runs on a faraday generator and just needs a few shakes for its operation.
- Battery less LED Dice: An electronic dice which generates numbers from 1 to 6 randomly. It uses a faraday generator for power.
- Birthday Blowout Candles: Fireless programmable birthday candles that go off when blown and also play a happy birthday song!
- Electronic Hourglass: A MSP430 puppy based LED hourglass with a novel orientation sensor. Also equipped with timeout buzzer.
- Cricket and 1D Pong: Implements two player 1-D Pong and Cricket games based on LFSR.
- Internal and external temperature sensor and Mux’ed SSD: Displays the ambient as well as CPU core temperature in both Celsius and Fahrenheit scales on 7- segment displays.
- LED Inauguration Lamp System: An inauguration lamp that doesn’t involve fire. It has a 3-D printed fake fire flames, along with an electronic matchstick.
- LED Spinning Top: A top which prints messages as it spins.
- Hacked Toy Laser Gun: Electronic laser target shooting practice game with LED targets.
- Electronic visiting card: A visiting card printed on a PCB that can be plugged into a USB port redirecting the user to the website of the person who owns it.
- Customized Memento: A personalized electronic memento, which shows the use of LED as a sensor.
- 2 and a 1/2-digit Charlieplexed Display: A display made using 20 charlieplexed LEDs using an 8 pin microcontroller.
- Hearty: A wearable interactive LED heart. The heartbeat speeds up if anyone comes close to it and displays interesting patterns.
- Smart egg tray: An egg tray which notifies when the numbers of eggs kept in it falls below a threshold number. Based on the IoT paradigm.
- RGB color mixer: Controls the intensity of red, green, blue colors to make millions of new colors.
- RGB LED Pen: A pen which can make 7 colors using the RGB combinations.
- Spectrum analyzer: Classifies audio frequency spectrum into different bands and displays it in the form of bar graphs on a LCD screen.
- Illuminated eye loupe: A lens with LEDs supporting it, for better vision in dark also.
- CPLD based game Race of Gladiators: A CPLD based game which uses LEDs arranged in a circular pattern, switches and random number generator.
- GAMMA: A smart device that can be attached to a toothbrush and can tell if the person has brushed their teeth well, using an app.
- LED Tengu: A device which takes audio input and lip syncs it using LEDs.
- Talking Thermometer: A multi-lingual thermometer that speaks out the current temperature in Celsius or Fahrenheit scales. A useful device for the visually impaired.
Display of the projects under CEDT/ TI CEPD and books by Prof. Dhananjay V. Gadre
Prof. Gadre giving a demonstration of birthday blowout candles
The morning session began with the demonstration of speaker as a microphone, showing how a moving coil (attached to the diaphragm of the speaker) in a magnetic field could produce a voltage. Next, a dc motor was made to work as a generator and the generated voltage was used to power an LED. Then, an experiment showing the working of a Peltier module was shown. Peltier module is a thermocouple which responds to the voltage applied across it in the form of a temperature difference by making one side hot and the other side cold. On the other hand, in another experiment, a temperature difference applied across a peltier module was used to generate power.
Response of a speaker working as a microphone recorded on an oscilloscope
Motor made to work as a generator to power up an LED
Heating of a peltier module to generate potential difference across its ends
Following this, an introductory talk on ‘Embedded System Design’ was given. It started with a discussion about ‘What are embedded systems and where are they found? Some examples of embedded systems being used at home like the refrigerator, AC, TV remote were discussed Following this, some observations were drawn, enlightening the participants about the size of the Embedded Systems Industry and microcontroller/microprocessors with the software’s running on them as the core of this entire system. It is estimated that for India alone, this industry requires an input of about 32 lakh crore rupees by 2020.
Then a comparison was drawn between ‘Embedded Systems’ and ‘Desktop Computers’, discussing each of them at levels like cost involved, reliability and accuracy constraints, task specifications, real time use, resources involved and programming needs.
A graph was plotted between ‘Probability of Failure’ and the ‘Age of a product’, which described how prone a product is to failure at various stages of its life span. This curve came to be known as the ‘Bath tub curve’.
Post Lunch – EAGLE CAD
This session was about using a CAD software named ‘EAGLE’ to make schematics and board layouts headed by Abhishek Kapoor and Arun Kumar (currently pursuing B.E., 7th semester, ECE division, NSIT). It stands for Easily Applicable Graphical Layout Editor. During this session, the participants were explained the various tools used to make a schematic diagram in EAGLE and as an exercise, the schematic diagram of a common emitter (CE) amplifier circuit was made and the code practice oscillator (CPO) circuit was given as homework for practice.
A CE amplifier schematic practiced during lecture
The morning lecture was taken by Prof. Gadre continuing with TALK -1: Introduction to Embedded System Design. At first, emphasis was laid on understanding the different terminologies involved such as microprocessor, microcomputer, microcontroller and SoC (System on chip) and how we differentiate one from the other. The associated development tools such as assembler, compiler, debugger, emulator and evaluation kit were introduced.
Next in line were the two different types of instruction set architecture for the processors – CISC and RISC. CISC stands for Complex Instruction Set Computer whereas RISC for Reduced Instruction Set Computer. The advantages and drawbacks of one over the other were discussed.
The evolution of the microcontrollers beginning from 4 and 8 bits to as it stands today (16, 32 and 64 bits) was discussed.
Then Professor introduced a very fascinating idea of Six Box Model of an Embedded System in which he categorized every element of an embedded system into these under mentioned six boxes. Numerous input and output peripherals were discussed in great detail.
Six-Box Model of an Embedded System
Post lunch – EAGLE CAD
Post lunch session was taken by Abhishek Kapoor. He continued with the lecture on various tools necessary for making a schematic in EAGLE. After tea break, participants were introduced to the most interesting aspect of this CAD tool-Routing the board layout of a schematic.
The day began with a talk on optocoupler and optoisolator. The application of optocoupler in printer heads and optoisolator in isolating two systems using light, by providing two different grounds seemed very fascinating to the participants . For keeping a track of time, the RTC (Real time clock) was explored. A task, to find a solution for the battery backup of the RTC, in case of power failure, was also given . A simple solution to this, using two diodes was explained.
The processor, host, the power supply to the system, the communication links within the system and with the outside world were introduced. After reviewing all the six boxes, sir went on to describe how to form a union of these elements with the “electronic glue”. Electronic glue could be any analog circuitry which would measure, filter, amplify signals or process these 6 boxes.
Prof. Gadre involved in a discussion about optocoupler
Post lunch – EAGLE CAD
Post lunch, the EAGLE session was continued. The participants were taught the various tools associated with making the board layout. The board layout of the common emitter was completed by each participant. The routing of the Code Practice Oscillator (CPO) that they would be fabricating soon, was given as an exercise. Their mistakes were corrected and their doubts were attended by the mentors. Also, a separate EAGLE lecture was arranged for those participants who had joined late, so that they could catch up with the rest of the class.
A glimpse of the schematic and board file of the CPO board
Common lecture- EAGLE CAD
Sometimes for your project you find a new component for which a suitable library does not exist. Then what do you do? Create your own library. Yes, this lecture was about creating your own library in Eagle.
Creating a new library is a simple and engaging process. A representative symbol of the component is created followed by designing of an appropriate package using the dimensions given in the datasheet (or sometimes dimensions have to be measured using a vernier callipers and screw gauge). Then the pins on the symbol are mapped on to the pins of the package to create the new device.
After the lunch break the participants got an opportunity to learn the nitty-gritties of fabricating a printed circuited board (PCB).
The board layout for the code practice oscillator (CPO) circuit was prepared by the participants themselves. The schematic and board layout were then verified by their mentors before the commencement of the fabrication process.
The entire fabrication process took 3 days for completion which involved several steps as listed below:
- Printing the board layout on a glossy paper
- Preparing the surface of the copper clad board using a sand paper to remove the oxide layer which is non- conducting and has been deposited over time.
- Transferring the ink by pressing: The toner transfer method.
- Removing paper by washing.
- Etching the copper clad by using FeCl3 solution so as to remove the excess copper.
- Scrubbing off the ink to expose copper tracks.
- Using Acrylic spray film to prevent formation of copper oxide.
- Filing out the projections on the edges.
- Soldering the components on the PCB.
- Testing the PCB.
By the end of the day many participants had completed their boards till the drilling process.
Overview of the steps involved in DIY PCB Fabrication
Participant involved in etching process
PCB after scrubbing
The participants were introduced to the most crucial step in the fabrication process i.e. soldering. The entire process was demonstrated and the intricacies involved were discussed before the participants began soldering their boards. The completed circuits went through the testing process and were checked for errors by the mentors.
By the end of the day majority of the participants had their first completed and tested board in their hands.
Completed CPO board
Testing of the CPO board
An extra class was held by Professor Dhananjay Gadre for about 20 late joiners. It covered all the demos and project ideas that were demonstrated on Day 2. Sir also briefed them about embedded systems and the six box approach.
The theme of the lecture was to instill in the participants an undying love for electronics and to inspire them to start thinking creatively and converge innovatively towards their project ideas. After the lunch break, the leftover fabrication was completed under the supervision of the mentors.