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haas:fall2020:common:projects:led0 [2020/08/25 15:10] – [(1) breadboard] wedgehaas:fall2020:common:projects:led0 [2020/09/18 13:28] (current) – [The Circuit to Construct] wedge
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 =====Objective===== =====Objective=====
-To create a program that generates a unique pattern of lit LEDs on your pi based on constraints+To successfully interface an LED to your pi and control it via software (commands, provided program)
  
-{{page>haas:fall2020:common:projects:abstract}}+We also further utilize enforced time constraints, tying project credit to your starting on the project before the deadline (so be sure to plan accordingly!) 
 + 
 +=====Abstraction===== 
 +{{page>haas:fall2020:common:projects:abstraction&noheader}}
  
 =====Locational Awareness===== =====Locational Awareness=====
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 <cli> <cli>
-yourpi:~/src/c4eng/led0$ gpio readall+yourpi:~/src/desig/led0$ gpio readall
  +-----+-----+---------+------+---+---Pi 4B--+---+------+---------+-----+-----+  +-----+-----+---------+------+---+---Pi 4B--+---+------+---------+-----+-----+
  | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |  | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
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  | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |  | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
  +-----+-----+---------+------+---+---Pi 4B--+---+------+---------+-----+-----+  +-----+-----+---------+------+---+---Pi 4B--+---+------+---------+-----+-----+
-yourpi:~/src/c4eng/led0$ +yourpi:~/src/desig/led0$ 
 </cli> </cli>
  
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 {{ :haas:fall2020:common:projects:breadboard.jpg |}} {{ :haas:fall2020:common:projects:breadboard.jpg |}}
 +
 +<WRAP round info>We will be inserting the metal legs of various components in various holes on the breadboard, to connect our circuit together.</WRAP>
 +
 +On the breadboard, there are 2 different pathways of connectivity. If you look along the top and bottom of the breadboard, do you see the red and blue strip running horizontal across the board? That means that ALL pins in that row are hooked together (all the pins along the blue line are hooked together with each other, all the pins along the red lines are hooked together with each other). We will be using that to to provide things like a common voltage (+) or a common ground (-) to components that need such things.
 +
 +In the middle of the breadboard, separated by the valley in the plastic molding, are columns of connected pins (unique columns, also separate from the other side of the valley). Each group of those 5 pins is hooked together.
 +
 +You'll notice occasional "by 5" counting off silkscreened on the breadboard, which can be used to try to keep things organized.
 +
 +Here's a logical diagram of the breadboard layout:
 +
 +{{ :haas:fall2020:common:projects:breadboardlogic.png?400 |}}
 +
 +Here's a good video overview of the functionality of a breadboard:
 +
 +  * https://www.youtube.com/watch?v=6WReFkfrUIk
 ====(1) T-cobbler and data cable==== ====(1) T-cobbler and data cable====
 In your kit should be a T-shaped device (known as the "T-cobbler" with some aspect of pin names silkscreened on it, and a 40-pin ribbon cable). Colors may vary, but essentially it looks like this: In your kit should be a T-shaped device (known as the "T-cobbler" with some aspect of pin names silkscreened on it, and a 40-pin ribbon cable). Colors may vary, but essentially it looks like this:
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 <WRAP round info>Unlike the LED, where the direction of connection matters, it does not matter which way you plug in a resistor. Its purpose is simply to resist.</WRAP> <WRAP round info>Unlike the LED, where the direction of connection matters, it does not matter which way you plug in a resistor. Its purpose is simply to resist.</WRAP>
-====male to male connector wire, as needed====+====male to male jumper wire, as needed==== 
 +As a final piece of equipment you will need, locate and have a few male-to-male jumper wires handy for use in our circuit:
  
 +{{ :haas:fall2020:common:projects:male_male_jumper.jpg?400 |}}
  
 +=====The Circuit to Construct=====
 +With those components, you will want to place them onto your breadboard in a manner similar to this:
  
-=====Program===== +{{ :haas:fall2020:common:projects:led_circuit.png?400 |}}
-It is your task to write a program to interface with an LED (light emitting diode), a nice software-hardware connection, on your raspberry pi.+
  
-====On your pi==== +Take note of how everything is being plugged in, and what connection on the T-cobbler is being utilized.
-Develop, test, and run this program on your pi. When done, submit it on lab46.+
  
-To utilize the needed functionality for this project, you will need to ensure you have the following packages installed:+Notice how the circuit runs from ground to LED to resistor to pin "GPIO17/Physical pin 11/Wiring Pi pin 0"
  
-  * **build-essential** (hopefully you took care of this in ntr0) +Before you seek to actually test your circuit, please get verification to proceed from the class channel on discord by posting a clear picture of everything. There are MANY moving parts, and especially as we have our first exposure, it is best to insert as many quality control checks as possible to ensure the greatest chances of mistakes are mitigated.
-  * **wiringpi**+
  
-===Installing wiringpi=== +====Testing connectivity==== 
-An exception to the usual package installation process, especially for those with a Raspberry Pi model 4B: when you install **wiringpi** the usual way, we may end up with errors when proceeding further, such as the following:+To verify whether everything is hooked up correctly (including the correct positioning of the LED), please try the following: 
 + 
 +===Set wiringPi pin 0 to OUTPUT mode=== 
 +Remember in that big readout of all the gpio pins above? Take a look at the settings for wiringPi pin 0:
  
 <cli> <cli>
-yourpi:~/src/c4eng/led0$ gpio readall + +-----+-----+---------+------+---+---Pi 4B--+---+------+---------+-----+-----+ 
-Oops - unable to determine board type... model: 17+ | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM | 
 + +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+ 
 + | ... 
 + |  17 |   0 | GPIO. 0 |   IN | 0 | 11 |
 </cli> </cli>
  
-What you will need to do is manually install an updated (and out of database) version of the **wiringpi** package, as follows (looking out for errors along the way):+Note that, currently wPi pin 0 is set to INPUT (with no voltage). We need to change that to OUTPUT, which you can do by doing the following:
  
 <cli> <cli>
-yourpi:~/src/c4eng/led0$ wget https://project-downloads.drogon.net/wiringpi-latest.deb +yourpi:~/src/desig/led0$ gpio mode 0 OUT
-... +
-yourpi:~/src/c4eng/led0$ sudo dpkg -i wiringpi-latest.deb +
-... +
-yourpi:~/src/c4eng/led0$ rm -f wiringpi-latest.deb+
 </cli> </cli>
  
-===The program (led0.c)=== +At which point that particular pin will be changed from IN to OUT:
-The program you will need is once again provided via a grabit on lab46, source code also included here for study:+
  
-<code c> +<cli> 
-#include <stdio.h>     // include support for C standard library input/output functionality + +-----+-----+---------+------+---+---Pi 4B--+---+------+---------+-----+-----+ 
-#include <stdlib.h>    // include support for general C standard library functionality + | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM | 
-#include <wiringPi.h>  // include support for wiringPi library functionality+ +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+ 
 + | ... 
 + |  17 |   0 | GPIO. 0 |  OUT | 0 | 11 | 
 +</cli>
  
-int main (void)        // every program has a starting point, for us in C, it is main() +Okay, output mode enabled, now to twiddle the bits off and on:
-{ +
-    ////////////////////////////////////////////////////////////////////////// +
-    // +
-    // Declare variables +
-    // +
-    int gpio_pin  = 17;   // set to GPIO pin we are hooking LED circuit into+
  
-    ////////////////////////////////////////////////////////////////////////// +<cli> 
-    // +yourpi:~/src/desig/led0$ gpio write 0 1      ## activate voltage on wiringpi pin 0 (turn on) 
-    // Initialize wiringPi subsystem and verify no errors occurred +yourpi:~/src/desig/led0$ gpio write 0 0      ## deactivate voltage on wiringpi pin 0 (turn off) 
-    // +</cli>
-    if (wiringPiSetup() == -1) +
-    { +
-        fprintf (stderr, "[error] wiringPi initialization has failed!\n"); +
-        exit (1); +
-    }+
  
-    ////////////////////////////////////////////////////////////////////////// +If your LED is hooked up correctly, the LED should light up, ideally during the ON line.
-    // +
-    // Display usage information to the user +
-    // +
-    fprintf (stdout, "Starting program, interrupt to terminate (CTRL-c)\n");+
  
-    ////////////////////////////////////////////////////////////////////////// +If you get no activity out of the LED, try reversing it and try again.
-    // +
-    // Initialize utilized GPIO pin to OUTPUT mode +
-    // +
-    pinMode (gpio_pin, OUTPUT);+
  
-    ////////////////////////////////////////////////////////////////////////// +=====Program===== 
-    // +It is your task to compile, run, and understand a program to interface with an LED (light emitting diode), a nice software-hardware connection, on your raspberry pi.
-    // Repeat until interrupted (CTRL-c to interrupt) +
-    // +
-    while (1) +
-    { +
-        digitalWrite (gpio_pin, LOW);   // set signal on gpio_pin LOW +
-        delay (1000);                   // delay for 1000ms +
-        digitalWrite (gpio_pin, HIGH);  // set signal on gpio_pin HIGH +
-        delay (1000);                   // delay for 1000ms +
-    }+
  
-    return (0); +The program files provided for this project are complete. You merely have to get it on your pi, compile it, and run it, with the appropriate circuitry hooked up to the specified places. You will want to make sure you UNDERSTAND what is going on.
-} +
-</code>+
  
-The program for this project is complete. You merely have to get it on your pi, compile it, and run it, with the appropriate circuitry hooked up to the specified places. In future projects you will start implementing more logic to attain further functionality. +In future projects you will start implementing more logic to attain further functionality.
-=====Specifications===== +
-Your program should:+
  
-  * have valid, descriptive variable names of length //no shorter than// 4 symbols +====Grabbing project resources (on lab46)====
-  * have consistent, well-defined indentation (no less than 4 spaces per level of indentation) +
-    * all code within the same scope aligned to its indentation level +
-  * have proximal comments explaining your rationale and what is going on, throughout your code +
-  * perform the intended operation, outputting the correct/accurate information in indicated format +
-  * at the end of your main() function, use a single return statement to conclude your code, return a 0 indicating successful operation +
- +
-=====Grabbing project resources=====+
 I have prepared a **grabit** for resources related to this project. To obtain: I have prepared a **grabit** for resources related to this project. To obtain:
  
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 At which point you can change into the newly created and populated **led0** directory. At which point you can change into the newly created and populated **led0** directory.
 +
 +====Getting project resources from lab46 to your pi====
 +Okay, you've snagged the project files on lab46. Now, how to get them to your pi?
 +
 +The same way you've been juggling project files already, by using your mercurial repository!
 +
 +Using the **hg** tool, be sure to **add**, **commit**, and **push** successfully on lab46.
 +
 +Then, over on your pi, use **hg** to **pull** and **update** the new changes into place. Then you can proceed.
 +
 +====On your pi====
 +Study and run this program on your pi in conjunction with testing and verifying operation of your properly hooked up electronics circuit. When done, submit it on lab46.
 +
 +To utilize the needed functionality for this project, you will need to ensure you have the following packages installed:
 +
 +  * **build-essential** (hopefully you took care of this in ntr0)
 +  * **wiringpi**
 +
 +===Installing wiringpi===
 +An exception to the usual package installation process, especially for those with a Raspberry Pi model 4B: when you install **wiringpi** the usual way, we may end up with errors when proceeding further, such as the following:
 +
 +<cli>
 +yourpi:~/src/desig/led0$ gpio readall
 +Oops - unable to determine board type... model: 17
 +</cli>
 +
 +What you will need to do is manually install an updated (and out of database) version of the **wiringpi** package, as follows (looking out for errors along the way):
 +
 +<cli>
 +yourpi:~/src/desig/led0$ wget https://project-downloads.drogon.net/wiringpi-latest.deb
 +...
 +yourpi:~/src/desig/led0$ sudo dpkg -i wiringpi-latest.deb
 +...
 +yourpi:~/src/desig/led0$ rm -f wiringpi-latest.deb
 +</cli>
  
 =====Compiling===== =====Compiling=====
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   * Track/version the source code in a repository   * Track/version the source code in a repository
   * Submit a copy of your source code to me using the **submit** tool.   * Submit a copy of your source code to me using the **submit** tool.
 +  * Post required images and obtain needed confirmation to proceed from me on class channel on discord.
  
 To submit this program to me using the **submit** tool, run the following command at your lab46 prompt: To submit this program to me using the **submit** tool, run the following command at your lab46 prompt:
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 <code> <code>
 26:led0:final tally of results (26/26) 26:led0:final tally of results (26/26)
-*:led0:post picture of unpowered layout to #desig and get approval [4/4] +*:led0:post picture of unpowered layout to #desig and get approval [6/6] 
-*:led0:post picture to #desig by Sunday before deadline [2/2] +*:led0:post picture to #desig by Sunday before deadline [4/4] 
-*:led0:post picture of powered LED to #desig [4/4]  +*:led0:post picture of powered LED to #desig [6/6]  
-*:led0:grabit the code on lab46 by Sunday before deadline [2/2]+*:led0:grabit the code on lab46 by Sunday before deadline [4/4]
 *:led0:code is pushed to lab46 repository [6/6] *:led0:code is pushed to lab46 repository [6/6]
-*:led0:no negative compiler messages for program [6/6] 
 </code> </code>
  
haas/fall2020/common/projects/led0.1598368200.txt.gz · Last modified: 2020/08/25 15:10 by wedge

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