When Texas Instruments (TI) introduced their new value line 16-bit microcontroller complete with the programmer and development board named MSP430 Value Line LaunchPad in the mid of 2010 for only USD 4.30 include the shipping cost, this make it as the cheapest programmer and development board platform that you could ever find in the market. Therefore the introduction of the MSP430 value line LaunchPad development board make a tremendous impact especially among the electronics hobbyist, students, and enthusiast because now the big boy (TI) is seriously taking part in the electronic hobbyist market and directly compete their 16-bit class value line microcontrollers to the 8-bit class microcontrollers which are mostly dominated by Atmel and Microchip.
The MSP430 Value Line LaunchPad development board is come with the eclipse based Texas Instruments integrated development environment (IDE) called Code Composer Studio (downloadable from the TI website) and equiped with the professional grade C compiler and debugger, which make the development of MSP430 microcontroller based embedded system become easy and fun.
As you know most of the electronics hobbyist used the popular 8-bit class microcontroller to most of their embedded project such as AVR microcontroller from Atmel and PIC microcontroller from Microchip. Now you might wonder why we have to learn another type of microcontroller as most of the modern microcontroller has already provided all the necessary features that we need. Why not, learning another type of microcontroller is one of the fascinating and challenging topics to be learned especially for the true electronics hobbyist as this will broaden our knowledge and utilize what is the best on each of the microcontroller types to support our future embedded system project.
The MSP430 Microcontroller Project
After many considerations of what is the attractive way to introduce this MSP430 microcontroller, instead of just started with a common blinking LED, I decided to built a simple and yet most popular robot,…yes,…is another Line Follower Robot (LFR) using the Texas Instruments 14 pins 16-bit MSP430G2231 microcontroller that come with the MSP430 Value Line LaunchPad development board. Because I think building a robot will give you the basic knowledge and understanding you needs to start explores many of the advance features offered by this 16-bit MSP430 value lines microcontrollers by yourself.
If you notice on the above picture this Line Follower Robot (LFR) used a similar CD chassis, DC geared motor, and sensors found on my previous articles “The LM324 Quad Op-Amp Line Follower Robot with Pulse Width Modulation“. Therefore this project also serves as a good example of the “digital” version of the analog LFR we’ve built before.
The following is the complete electronic schematic of the Line Follower Robot:
Now let list down all the necessary electronic components and other supported materials to build this LFR:
1. Resistors: 220 (2), 470 (1), 10K (3), 22K (2), and 47K (1)
2. Light Dependent Resistor (2)
3. Capacitors: 0.1uF (3), 1uF (1) and 47uF/16v (1)
4. Diodes: 1N4148 (2)
5. High Intensity 3 mm blue Light Emitting Diode (3)
6. N-Channel MOSFET: BS170 (3)
7. IC: ACS 1722A 3.3 volt voltage regulator or equivalent
8. Texas Instruments MSP430 Value Line LaunchPad Development Board
9. DC Motor: Solarbotics GM2 Geared DC motor with Wheel (2)
10. One reset push button switch
11. Perforated PCB: 70 x 55 mm for the main board and 50 x 15 mm for the sensors board
12. 4 x AA Battery holder
13. CD/DVD ROM (2)
14. Plastic Beads and Paper Clip for the castor (the third wheel)
15. Bolt, Nuts, Double Tape and Standard Electrical Tape for the black line
16. Texas Instruments Code Composer Studio Core Edition version 4.2.1.00004 (used in this project)
17. Texas Instruments MSP430G2231 microcontroller datasheet SLAS694 and SLAU144F.
The Line Follower Robot Working Principle
This Line Follower Robot design used the photocell sensor known as a Light Dependent Resistor (LDR) made from Cadmium Sulphide (CdS) to detect the black track line, when the LDR is above the black track line it will give a high resistance value while above the white background and it will give a low resistance value. Together with the 22K resistor, they will form what’s known as the voltage divider circuit. This voltage divider circuit sensor will provide the varying voltage according to the amount of the light intensity reflected back to the LDR. The blue Light Emitting Diode (LED) will provide a constant light source for the sensors.