Arduino/C3/Digital-Logic-Design-with-Arduino/English-timed
From Script | Spoken-Tutorial
| Time | Narration |
| 00:01 | Welcome to the Spoken Tutorial on Digital Logic Design with Arduino. |
| 00:07 | In this tutorial, we will learn to: implement and verify the AND, OR and XOR operations in assembly, |
| 00:17 | implement and verify simple Combinational Logic. |
| 00:21 | To follow this tutorial, you should have basic knowledge of electronics and Assembly language. |
| 00:31 | To record this tutorial, I am using: Arduino UNO Board |
| 00:38 | and Ubuntu Linux operating system version 14.04. |
| 00:44 | We also require some external devices such as:
Breadboard, |
| 00:51 | Arduino UNO Board, |
| 00:54 | Seven Segment Display, |
| 00:57 | 220-ohm Resistor, |
| 01:00 | Decoder (7447 IC) and
Jumper Wires. |
| 01:07 | We will use the same circuit setup as we did for the decoder, in the earlier tutorial. |
| 01:14 | Let us see the live connection setup. |
| 01:17 | Now, we will write an assembly program to verify the logical AND operations. |
| 01:24 | Open any text editor and type the following program. |
| 01:29 | m328Pdef.inc file and the source code are available in the code files link of this tutorial. |
| 01:38 | You can download and use it. |
| 01:41 | The highlighted code configures pins 2, 3, 4 and 5 of the Arduino as output pins. |
| 01:49 | We are considering only the first bit of r16 and r17 for our boolean operations. Here, both are 1. |
| 02:00 | This line performs bitwise AND operation on the bits of r16 and r17. The result is stored in r16. |
| 02:12 | The rest of the program takes care of displaying this output. |
| 02:17 | The LSB of r16 has our result. This has to be shifted by two positions to the left. |
| 02:26 | This line of code calls the loop named loopw. |
| 02:31 | This loop takes care of shifting the LSB of r16 twice. |
| 02:38 | The value in r16 is sent to PORTD. This displays either 0 or 1 on the Seven segment display. |
| 02:48 | Here, contents of r16 are left shifted once. Then the value of r20 is decremented by 1. |
| 02:58 | If the value of r20 is not equal to zero, the loop is repeated again. |
| 03:05 | I’ll save the code as boolean.asm in the home slash spoken slash Assembly folder. |
| 03:15 | Switch to the terminal. |
| 03:18 | Go to the folder where boolean.asm file is saved. Type: avra space boolean.asm and press Enter. |
| 03:29 | This will assemble the code and create a file boolean.hex. |
| 03:34 | Let us clear the screen. |
| 03:36 | Next, we need to upload the code to the Arduino. |
| 03:41 | For this, type: avrdude space hyphen p space atmega328p space hyphen c space arduino space hyphen b space 115200 space hyphen capital P space forward slash dev forward slash ttyACM0 space hyphen capital U space flash colon w colon boolean dot hex
and press Enter. |
| 04:17 | Now, you can see that the digit one on the seven segment display is glowing. |
| 04:23 | Pause the tutorial and do the below assignment. |
| 04:27 | Modify the values of r16 and r17 to verify the rest of the truth table of AND. |
| 04:35 | Replace the keyword and in the program with or to perform logical OR operation. |
| 04:42 | Replace the keyword and in the program with xor to perform logical XOR operation. |
| 04:49 | Next, we will implement and verify few simple combinational logics. |
| 04:55 | Let us see the live connection setup. It will be the same as the previous setup. |
| 05:02 | We are going to implement these equations in our program and verify their truth table. |
| 05:09 | This is the truth table for the equations shown above. |
| 05:14 | Here W, X, Y and Z are the inputs. |
| 05:19 | A, B, C and D are the outputs. Let us consider the first row of the truth table. Thus, all the inputs will be zeros. |
| 05:31 | As per the truth table, we can expect the output as 1. |
| 05:36 | We will display the output on the seven segment display. |
| 05:40 | Let us write an assembly program to implement and verify these equations. |
| 05:46 | Open any text editor and type the following program. |
| 05:50 | Let me explain the program. |
| 05:53 | This line configures pins 2,3,4 and 5 of the Arduino as output pins. |
| 06:00 | r30 is a dummy variable for storing the output. |
| 06:05 | The values of input variables W, X, Y and Z are stored in registers r17, r18, r19 and r20 respectively. |
| 06:16 | The values of r17, r18, r19 and r20 are stored in the dummy variables r0, r1, r2 and r3. |
| 06:27 | These values are used to restore the original registers after performing operations. |
| 06:35 | The 'comp' subroutine is used to find the complement of a variable. |
| 06:41 | The complement of W, X, Y and Z are calculated and stored in r21, r22, r23 and r24 respectively. |
| 06:52 | The values of r21, r22, r23 and r24 are stored in the dummy variables r4, r5, r6 and r7. |
| 07:04 | Note that A is nothing but the complement of W.
Now, we have implemented the first equation. |
| 07:12 | Next, we perform two left shift operations and store the value in r30.
Thus, the third bit of the r30 has the value of A. |
| 07:24 | The 'reload' subroutine reloads the values r0, r1, r2, r3, r4, r5, r6 and r7 from its copies. |
| 07:36 | They might have changed during previous operations. |
| 07:41 | The logic for B is implemented and the result is stored in r0. |
| 07:47 | The value in r0 is left shifted thrice and stored in r30. |
| 07:54 | Now, the fourth bit of r30 holds the result of B. |
| 08:00 | The logic for C is implemented and the result is stored in r0. |
| 08:06 | The value in r0 is left shifted four times and stored in r30. |
| 08:13 | Now, the fifth bit of r30 holds the result of C. |
| 08:19 | The logic for D is implemented and the result is stored in r0. |
| 08:25 | The value in r0 is left shifted five times and stored in r30. |
| 08:32 | Now, the sixth bit of r30 holds the result of D. |
| 08:38 | Finally, the value stored in r30 is sent to PORTD to be displayed. |
| 08:46 | Save the code as combination.asm in the home slash spoken slash Assembly folder. |
| 08:55 | Switch to the terminal. |
| 08:58 | Type: avra space combination.asm and press Enter. |
| 09:05 | This will assemble the code and create a file combination.hex.
Let us clear the terminal. |
| 09:14 | To upload, press the up arrow to get the previous command. |
| 09:19 | Now change the filename as shown and press Enter. |
| 09:26 | Now you can verify the truth table with the output shown on the seven-segment display. |
| 09:34 | Pause the tutorial and do the below assignment. |
| 09:38 | Change the values of W, X, Y and Z and verify different rows of the truth table. |
| 09:46 | This brings us to the end of this tutorial. Let us summarize. |
| 09:52 | In this tutorial, we learnt to: implement and verify the AND, OR and XOR operations in assembly, |
| 10:01 | implement and verify simple Combinational Logic. |
| 10:05 | The video at the following link summarizes the Spoken Tutorial project.
Please download and watch it. |
| 10:13 | The Spoken Tutorial Project team conducts workshops and gives certificates.
For more details, please write to us. |
| 10:23 | Please post your timed queries in this forum. |
| 10:27 | Spoken Tutorial project is funded by NMEICT, MHRD, Government of India.
More information on this mission is available at this link. |
| 10:38 | This tutorial has been contributed by FOSSEE' and Spoken Tutorial Project, IIT Bombay'.
This is Priya from IIT Bombay, signing off. Thanks for watching. |
