MPC 10C Labs for the Arduino Uno R3

Using C: Classroom Edition Fall 2024

Setup Files:

Setup files for env.make and VS Code

Introduction

This repository is for an introductory course on the C language using the Arduino Uno, the C tool chain (avr-gcc, avrdude etc) and the AVR C Library. The content is for students who desire understanding C using an embedded microcontroller, in this case the Arduino Uno R3. This content uses the avr tool chain via command line (also called the terminal), it doesn't use the Arduino IDE GUI nor does it use the Arduino software framework.

The directory, templates, contains the programs for labs. Each template folder contains multiple folders, each folder is a specific programming exercise. Within each exercise folder is a file called main.c and a file called Makefile. The file main.c is the template for the exercise and the Makefile is the required file using make to compile/link/load it to an UNO. Think of the main.c file as the Arduino IDE sketch and the Makefile as a command-line version of the Arduino IDE. The files in Library are similar to those found in the Arduino framework library.

Dependencies

The approach this class follows is to use a standardized platform running the C tool chain. This removes the pain of having to maintain documentation and support for each of the major computing platforms, macOS, Windows and Linux. Instead, the platform will be an inexpensive Raspberry Pi (RPi) running Raspberry Pi OS Bookworm with all of the required programs pre-installed.

In order to use this content you need to have the following installed on your computer or a computer you will be using in class:

• VS Code - Code editor, able to connect remotely to the RPi
• Terminal - command line interface, part of each operating system

Additional Sources of Information

• Developing in C on the AVR ATmega328P A series of web pages explaining in detail how to use specific aspects of the AVR C software framework.
• AVR LibC This library is the basis for the Clanguage for the AVR. From GNU "AVR Libc is a Free Software project whose goal is to provide a high quality C library for use with GCC on Atmel AVR microcontrollers."

Directories

Note: Library and examples will be maintained identical to the AVR_C versions

• examples - contains code demonstrating how to use specific functions in the Library
• Library - AVR C Library, specific Arduino functions rewritten in C such as analogRead(), analogWrite(), digitalRead(), and pinMode()
• templates - template directories for each of the lab execises. This directory must be duplicated to be used and called dev. This directory is tracked by git and could be over-written in the next clone operation.
• dev - the student's version of the templates directory, where the students will make changes to the lab files. This directory is not tracked by git and won't be overwritten.

Installation

For this class, all of the content will be pre-installed on the RPi. If you wish to create a similar RPi from scratch, here are the instructions.

Usage

The recommended method to develop code using this repository is to use VS Code and your terminal program, side-by-side. This allows you to quickly and easily perform functions in either window.

To start:

1. Connect the Uno to the Raspberry Pi via the USB cable.
2. Put the Raspberry Pi power supply into an outlet and connect the USB-C cable from the power supply into the USB C connector on the Raspberry Pi.
3. The Raspberry Pi red light will come on and the green light will blink sporadically. Allow the RPi to run for a few minutes on initial boot.

Terminal Steps

1. Open the Terminal application:
   • Windows, enter Terminal in the Windows search bar, click on either Terminal or Command Prompt
   • macOS, press Cmd-Space to pull up the search and enter Terminal then return
2. Make the Terminal window fill the right half of your monitor screen.
3. At the command prompt (this is the name of prompt in Terminal), enter *ssh [email protected], using your RPi username and hostname. The username will always be pi10C, your hostname will be labeled on the Raspberry Pi and follow it with a ".local".
4. If this the first time, you have connected, you will need to respond "yes" to "...continue connecting (yes/no/[fingerprint])?".

For example, it will look similar to this:

ssh [email protected]
The authenticity of host 'pi10c01.local (192.168.1.75)' can't be established.
ED25519 key fingerprint is SHA256:1xivnuODhnLQR0VzTC4JIlHzYzZ9/6zm9R/gjh6/TIo.
This key is not known by any other names.
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added 'pi10c.local' (ED25519) to the list of known hosts.
[email protected]'s password:

This will connect your computer to the RPi via a secure connection (SSH) and you will now be in the command line interface (CLI) of the Raspberry Pi.

VS Code Steps

In the steps below, Ctrl/CMD means press Ctrl on Windows/Linux or Command on a Mac.

1. Open VS Code on your computer.
2. Press Shift-Ctrl/CMD-P, to Show All Commands in VS Code.
3. Enter "remote" and click on "Remote-SSH: Connect to Host..."
4. Enter your RPi username and hostname like this: [email protected]
5. Enter your password when prompted
6. It will take a few minutes for VS Code to connect, then it will prompt for a folder to open.
7. Click on the blue box Open Folder then click on Labs_10C_Class in the selection dropdown. ALWAYS OPEN THE FOLDER AND NOT INDIVIDUAL FILES, it will make your life much easier!
8. If prompted, click on "Yes, I trust the Authors".
9. Make the VS Code window fill the left half of your monitor screen.

Your screen now similar to this, with VS Code on the left and Terminal on the right:

Confirm Working System

Confirm in Terminal

To confirm everything is setup correctly, please perform the following steps in your Terminal:

# change directories to the Labs folder
cd Labs_10C_Class/
cd examples/blink
make complete

If everything is successful, you will see the end of the screen printout look like this:

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.00 s

avrdude: device signature = 0x1e950f (probably m328p)
avrdude: Note: flash memory has been specified, an erase cycle will be performed.
         To disable this feature, specify the -D option.
avrdude: erasing chip
avrdude: reading input file main.hex for flash
         with 1698 bytes in 1 section within [0, 0x6a1]
         using 14 pages and 94 pad bytes
avrdude: writing 1698 bytes flash ...

Writing |                                                    | 0% 0.00 s avrdude: padding flash [0x0680, 0x06ff]
Writing | ################################################## | 100% 0.36 s

avrdude: 1698 bytes of flash written

avrdude done.  Thank you.

And your Uno will be blinking quickly (2.5 times per second).

Confirm in VS Code

Now switch to the VS Code window.

1. Make sure the top icon in the left-side panel is selected to view your files. The second panel will show EXPLORER at the top.
2. Click on the ">" to the left of examples, to show the folders.
3. Click on the ">" to the left of the folder blink to show the files.
4. Click on main.c to show the file in the main Editor window
5. Go to line 10 and change 200 to 1000
6. Press Shift-Ctrl/CMD-b and press return (compile and upload code (upload): flash)
7. After a small delay to compile and upload the code, the Uno will be blinking much slower (once per second).

If both tests worked, you are now ready to code!!!