MPC 10C Labs for the Arduino

Using C: Classroom Edition

Introduction

This repository is for the classroom using the Arduino Uno, the C tool chain (avr-gcc, avrdude etc) and the AVR C Library. It includes directories for all of the lab assignments along with examples as to how to use the AVR C Library. The content is for students who desire understanding C using the Arduino Uno.

Each lab contains multiple folders, each folder is a specific programming exercise. Within each 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.

In order to use this content, one must either use the Arduino tool chain via command line or have the GNU C tool chain installed on their computer. This post advises how to do either of these tasks on all three platforms, Linux, macOS and Windows.

Dependencies

In order to use this content you must have the following installed on your computer:

• Arduino Legacy IDE (1.8.x) - C tool chain, instructions are below
• Cool Term - serial monitor, instructions below
• Terminal - command line monitor, part of operating system
• Sublime Text or Notepad++ - code editor, installed by user

The instructions will refer to specific capabilities such as a code editor or C tool chain, use the list above to identify the programs associated with the capability.

Sources

• This repository
• Developing in C on the AVR ATmega328P
• AVR_C Github Repository This link is provided as additional documentation, the Library and examples in AVR_C are included in this repository. It is included in case, someone wants to have a public version available of these files.

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

1. Copy repository

This step will add the lab programming content to your system. If you have git (or want to learn how to use git) install git on your system. You may also simply download the repository as a zip file, extract it and copy to your Documents directory.

To download and extract

1. Click on the green button <> Code on the repository page.
2. With the tab showing "Local", got to the bottom option, Download ZIP.
3. Once downloaded, right click to either "Open with Archive Utility" (macOS) or Extract All... (Windows)
4. Move the folder extracted to your Documents directory.
5. Duplicate the templates folder and call it dev

To use git

Clone this repository to your system, follow all of the steps EXACTLY:

# open a terminal window in your operating system
# change your directory to where you want to keep this lab
cd Documents
# clone this repository to directory Labs_10C_Class
git clone https://github.com/lkoepsel/Labs_10C_Class.git
# switch to the cloned directory
cd Labs_10C_Class
# copy the templates folder to the new dev folder
cp -r templates dev

2. Change Makefile to Use Arduino Tool Chain

The Makefile has a variable TOOLCHAIN = , which allows you to use either, a system-installed toolchain (default, GNU C tool chain) or the toolchain installed by the legacy Arduino (1.8.x) IDE.

In order to use the latter, perform the following steps:

1. In your code editor, open the Makefile in the root directory, as in Labs_10C_Class/Makefile.
2. Add arduino to the TOOLCHAIN variable as in TOOLCHAIN = arduino
3. Uncomment, by removing the leading # (this is pound sign AND the following space) from the lines BIN = ... and AVRDUDECONF = ... lines appropriate to your operating system

Below is an example of the directions, using a Windows PC:

# Change the line below to TOOLCHAIN = arduino, if you want to use the Arduino IDE tools
# And uncomment the appropriate block of code based on your OS
TOOLCHAIN = arduino
ifeq ($(TOOLCHAIN), arduino)
	# macOS lines, remove both the # and the following space
	# BIN = /Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/
	# AVRDUDECONF = -C /Applications/Arduino.app/Contents/Java/hardware/arduino/avr/bootloaders/gemma/avrdude.conf

	# Windows lines, remove both the # and the following space
	BIN = 'C:\Program Files (x86)\Arduino\hardware\tools\avr\bin\'
	AVRDUDECONF = '-CC:\Program Files (x86)\Arduino\hardware\arduino\avr\bootloaders\gemma\avrdude.conf'	
else
	BIN =
	AVRDUDECONF = 
endif

The BIN = ... and AVRDUDECONF = ... lines must be indented only with a tab at the beginning of the line for make to accept the lines.

3. Create env.make

As env.make isn't backed up by git, you will need to create one. Again, use your code editor. Copy the contents then paste them into a new file. Save that file as env.make at the root level of your Labs_10C_Class folder (same level as the templates/ and dev/:

# This file contains the environmental variables to compile/link/load AVR_C
# Only one section may be used at a time, each section describes a specific board
# Comment out the sections which won't be used
# After switching boards, Library must be re-compiled
# Use "make LIB_clean" to force a re-compile of the Library

# Possible Serial Ports on Mac
# /dev/cu.usbserial-01D5BFFC
# /dev/cu.usbmodem5101
# /dev/cu.usbmodem14101

# Possible Serial Ports on Windows
# COM3
# COM4
# COM9

# Options for TOOLCHAIN are 'arduino' or blank
# Options for OS are 'mac' or 'windows'

# Arduino UNO and compatible boards
MCU = atmega328p
SERIAL = /dev/cu.usbmodem3101
F_CPU = 16000000UL
BAUD  = 250000UL
SOFT_RESET = 0
LIBDIR = $(DEPTH)Library
PROGRAMMER_TYPE = Arduino
PROGRAMMER_ARGS = -F -V -P $(SERIAL) -b 115200
TOOLCHAIN = arduino
OS = mac

## Microchip 328PB Xplained Mini environmental variables
# MCU = atmega328pb
# SERIAL = /dev/cu.usbmodem14102
# F_CPU = 16000000UL
# BAUD  = 9600UL
# SOFT_RESET = 0
# LIBDIR = $(DEPTH)Library
# PROGRAMMER_TYPE = xplainedmini
# PROGRAMMER_ARGS = 
# TOOLCHAIN = 
# OS = mac

You will need to set the following:

• SERIAL = to the serial port you found using the Arduino IDE
• TOOLCHAIN = arduino delete the word 'arduino if you wish to use the locally installed GNU C tool chain'
• OS = mac replace 'mac' with 'windows' if on a Windows PC

4. CoolTerm

Install or confirm CoolTerm is installed on your system. It is a Multi-platform serial monitor, for free and has phenomenal scripting capabilities as well.

ONLY DOWNLOAD FROM THIS SITE:

https://freeware.the-meiers.org Confirm the URL in your browser!

AND after downloading CoolTerm and before installing, please take one more step to confirm the image is the proper one. Roger Meier has done a great job in providing the checksums for the latest releases.

Changing Board Types

As the comments in the env.make file state, if you switch boards i.e; Uno to Xplained Mini (not Uno to different Uno) then the Library must be re-compiled. Use "make LIB_clean" to force a re-compile of the Library followed by a "make flash" or copy and paste below into your terminal:

make LIB_clean && make flash

This is also true if you change the MCU or F_CPU. This only needs to be performed once upon changing boards, MCU or F_CPU.