Developing for the Atmel AVR Microcontroller on Linux
Program space is a contiguous block of Flash memory, 16-bits wide that can be erased/rewritten 10,000 times. You can design your circuit to allow firmware upgrades in-circuit, using in-system programming.
All AVRs have some EEPROM, and most have SRAM; both are 8-bits wide. The EEPROM is designed to withstand at least 100,000 erase/write cycles. EEPROM is useful because it can be written from within your embedded program to retain data, even without a power supply, or during programming, such as for production-line calibration.
All AVRs, from the tiny 8-pin DIPs to the 44-pin Megas, have at least one data port. Data ports allow for input or output of logic-level data. The AVR ports are bidirectional, allowing you to set them for input or output on a pin-by-pin basis.
Many of the AVRs include additional hardware peripherals, such as UARTs for serial communication and calibrated RC oscillators used as internal system clocks. The external pins often serve two or more purposes, and how they are used depends on how you've configured the microcontroller. For instance, Figure 1 shows that certain I/O lines from both ports can be used with the multiplexed A/D converter.
The set of tools described here isn't the only one available, but it allows you to do basically anything, and the tools function well together. The toolkit is comprised of Binutils, GCC, AVR Libc and our Makefile template to write and build programs for the AVR microcontrollers; GDB and simulavr to debug your software; and avrdude as well as a hardware programmer to transfer your software to the microcontrollers. See the on-line Resources for download URLs for all software.
Fortunately, the recent versions of all these tools include support for the AVR platform, so installation is straightforward. We assume you've chosen to install everything under /usr/local/AVR.
Download a fresh copy of the current binutils source by following the link in the Resources. Untar the source, move into the binutils-X.XX directory and run:
$ ./configure --prefix=/usr/local/AVR --target=avr $ make # make install
The /usr/local/AVR/bin directory now contains AVR versions of ld, as, ar and the other binutils executables. Add the /usr/local/AVR/bin directory to your PATH now. You can apply the modification system-wide by adding:
to the /etc/profile file. Make sure the directory is in your PATH and that the change has taken effect before proceeding.
After retrieving a recent release of the Gnu Compiler Collection from a mirror, run the following commands from within the unpacked top-level source directory:
$ ./configure --prefix=/usr/local/AVR \ --target=avr --enable-languages="c,c++" \ --disable-nls $ make # make install
This builds C and C++ compilers for AVR targets and installs avr-gcc and avr-g++ in /usr/local/AVR/bin.
The AVR Libc package provides a subset of the standard C library for AVR microcontrollers, including math, I/O and string processing utilities. It also takes care of basic AVR startup procedures, such as initializing the interrupt vector table, stack pointer and so forth. To install, get the latest release of the library and run the following from the top-level source directory:
$ unset CC $ PREFIX=/usr/local/AVR ./doconf $ ./domake # ./domake install
The Psychogenic team has created a standard Makefile template that simplifies AVR project management. You can customize it easily for all your assembly, C and C++ AVR projects. It provides everything for a host of make targets, from compilation and upload to the microcontroller to debugging aids, such as source code intermixed with disassembly, and helpful gdbinit files. A detailed discussion of the template is available, and the Makefile template is available as Listing 1 on the Linux Journal FTP site (see Resources). Store the template with the other AVR tools, moving it to /usr/local/AVR/Makefile.tpl.
Fast/Flexible Linux OS Recovery
On Demand Now
In this live one-hour webinar, learn how to enhance your existing backup strategies for complete disaster recovery preparedness using Storix System Backup Administrator (SBAdmin), a highly flexible full-system recovery solution for UNIX and Linux systems.
Join Linux Journal's Shawn Powers and David Huffman, President/CEO, Storix, Inc.
Free to Linux Journal readers.Register Now!
|Fancy Tricks for Changing Numeric Base||May 29, 2016|
|Working with Command Arguments||May 28, 2016|
|Secure Desktops with Qubes: Installation||May 28, 2016|
|CentOS 6.8 Released||May 27, 2016|
|Secure Desktops with Qubes: Introduction||May 27, 2016|
|Chris Birchall's Re-Engineering Legacy Software (Manning Publications)||May 26, 2016|
- Tips for Optimizing Linux Memory Usage
- Working with Command Arguments
- Secure Desktops with Qubes: Introduction
- Secure Desktops with Qubes: Installation
- Download "Linux Management with Red Hat Satellite: Measuring Business Impact and ROI"
- Fancy Tricks for Changing Numeric Base
- CentOS 6.8 Released
- Linux Mint 18
- The Italian Army Switches to LibreOffice
- Chris Birchall's Re-Engineering Legacy Software (Manning Publications)
Until recently, IBM’s Power Platform was looked upon as being the system that hosted IBM’s flavor of UNIX and proprietary operating system called IBM i. These servers often are found in medium-size businesses running ERP, CRM and financials for on-premise customers. By enabling the Power platform to run the Linux OS, IBM now has positioned Power to be the platform of choice for those already running Linux that are facing scalability issues, especially customers looking at analytics, big data or cloud computing.
￼Running Linux on IBM’s Power hardware offers some obvious benefits, including improved processing speed and memory bandwidth, inherent security, and simpler deployment and management. But if you look beyond the impressive architecture, you’ll also find an open ecosystem that has given rise to a strong, innovative community, as well as an inventory of system and network management applications that really help leverage the benefits offered by running Linux on Power.Get the Guide