Ceci est une ancienne révision du document !
For a few challenges at home, I thought I could make some projects with a microcontroller. A microcontroller is small, affordable, and it seemed fun to learn something new. I chose the attiny13a from ATMEL Corp for my first few projects because this microcontroller is not too complicated (with a low pinout), but has enough functions for the first projects, and the attiny13a can operate under low power conditions. First, I tried the obvious for a beginner, and installed Arduino and the smeezekitty-core. But, after some experiments, the compiled code got too big and I had to often refer to the Help to look up the Arduino syntax. Thus, I was looking for a BASIC compiler for AVR for Linux – to flatten the learning curve and eventually get smaller hex files. After research, it shows that, unfortunately, most available products are for MS Windows. In the first place, I thought this was the case for Great Cow Basic - no Linux distribution. The Integrated Development Environment (IDE) or the Graphical Programming Tool are not (yet) available for Linux. However, the Great Cow BASIC compiler can run natively on Linux. And, to edit the source user programs in Linux, you could use any text editor you like. The result… a native Linux compiler, with an editor of my choice, and support for the microcontroller I had chosen.
Pour quelques défis à domicile, j'ai pensé que je pourrais faire des projets avec un microcontrôleur. Un microcontrôleur est petit et abordable, et il semblait amusant d'apprendre quelque chose de nouveau. J'ai choisis le attiny13a de ATMEL Corp pour les tout premiers projets car ce microcontrôleur n'est pas trop compliqué (avec peu de bornes), mais il a assez de fonctions pour les premiers projets ; le attiny13a peut fonctionner sous de conditions de puissance réduites. D'abord, j'ai essayé l'évidence pour un débutant et j'ai installé Arduino et et les fonctions centrales de « smeezekitty » (NdT : le développeur). Mais, après quelques essais, le code compilé devenait trop gros et je devais me référer souvent à l'aide pour vérifier la syntaxe d'Arduino. Ainsi, j'ai cherché un compilateur BASIC pour « AVR for Linux » - pour réduire la courbe d'apprentissage et éventuellement obtenir des fichier hexa plus petits. Après une recherche, il apparaît, malheureusement, que la plupart des produits disponibles sont pour MS Windows. Au début, j'ai cru que c'était le cas du compilateur Great Cow Basic - pas de distribution Linux. L'IDE (interface de développement intégré) ou l'outil de programmation graphique ne sont pas disponibles sous Linux. Et, pour modifier les source des programmes de l'utilisateur dans Linux, vous pouvez utiliser n'importe quel éditeur de texte que vous préférez. Le résultat… un compilateur natif Linux, avec l'éditeur de mon choix, un support pour le microcontrôleur que j'ai choisi.
GreatCowBasic Overview GreatCowBasic comes with a syntax similar to QBASIC/FreeBASIC, and supports flow control statements, math operators and data type, subroutines, functions, data tables, and inline assembler. On the hardware side, things like PWM, SPI, ADC and timer handling are handled via an extensive set of libraries. With GreatCowBasic, you can produce portable, reusable code for most 8-bit PIC and AVR microcontrollers (actually the project lists around 1100 supported chips); due to some hardware differences, one would have to change the code slightly if one changes from AVR to PIC and vice versa. In addition, the code is, as far as I can say, highly optimized both in speed and size aspects. Recently, a new version (v0.98.01) was released, for this article I used the former version (v0.97). I recommend using the newest release.
Présentation de GreatCowBasic
GreatCowBasic arrive avec une syntaxe similaire à celle de QBASIC/FreeBASIC, et supporte les déclarations de contrôle de flux, les opérateurs mathématiques et les types de données, les sous-routines, les fonctions, les tables de données et un assembleur en ligne. Du côté matériel, des choses comme PWM, SPI, ADC et la gestion d'un timer sont gérées via un ensemble étendu de bibliothèques.
Avec GreatCowBasic, vous pouvez produire du code portable et réutilisable pour la plupart des microcontrôleurs PIC et AVR (le projet liste actuellement à peu près 1100 puces supportées) ; du fait de certaines différences dans le matériel, le code devra être modifié légèrement en passant de AVR à PIC et vice-versa. De plus, le code est, pour autant que je puisse le dire, hautement optimisé à la fois en vitesse et en taille. Récemment, une nouvelle version(v0.98.01) a été publiée ; pour cette article, j'ai utilisé la version précédente (V0.97). Je recommande d'utiliser la plus récente.
Installation Because FreeBASIC and GreatCowBasic are not available through the package management, you have to install a binary tarball for FreeBASIC, and then compile GCB from source. To install FreeBASIC, the following commands (change x86 to x86_64 if using a 64 bit computer) should do. If it is more convenient for you, download the files with your browser of choice and omit the first lines. I assume you are in your home directory: wget ‘https://sourceforge.net/projects/fbc/files/Binaries%20-%20Linux/_ FreeBASIC-1.05.0-linux-x86.tar.gz' -O FreeBASIC.tar.gz tar xvf FreeBASIC.tar.gz cd FreeBASIC* sudo ./install.sh –i To get the compiler to work without the path prefix, make a softlink: sudo ln –s /opt/bin/fbc /bin/fbc
Installation
Parce que FreeBASIC et GreatCowBasic (GCB) ne sont pas disponible par la gestion des paquets, vous devez installer un tarball du binaire de Freebasic et, ensuite, compiler GCB à partir des sources.
Pour installer FreeBASIC, les commandes suivantes (modifiez x86 en x86_64 si vous utilisez un ordinateur 64-bit) feront l'affaire. Si vous préférez, téléchargez les fichiers avec votre navigateur Web préféré et sautez les premières lignes. Je suppose que vous êtes dans votre répertoire home :
tar xvf FreeBASIC.tar.gz
cd FreeBASIC*
sudo ./install.sh –i
Pour obtenir que le compilateur fonctionne sans chemin préfixé, faites un « softlink » (lien symbolique doux) :
sudo ln –s /opt/bin/fbc /bin/fbc
After that, the FreeBASIC compiler should just work; try with: fbc –version If you get an error message, or, later on, have issues with compiling, you may need some additional software in order to get the FreeBASIC compiler to run. With the following, you install the necessary libraries as stated in the FreeBASIC README: sudo apt install gcc libncurses5-dev libffi-dev libgl1-mesa-dev libx11-dev libxext-dev libxrender-dev libxrandr-dev libxpm-dev Get the archive from the GreatCowBasic project site, extract it with unrar (when prompted, enter the password “GCB”).
Après ceci, le compilateur FReeBASIC devrait marcher ; essayez avec :
fbc –version
Si vous obtenez un message d'erreur, ou, plus tard, si vous avez des problèmes en compilant, vous pourriez avoir besoin de logiciels additionnels pour permettre au compilateur FreeBASIC de fonctionner. Avc la ligne suivante, vous installez les bibliothèques nécessaires comme indiqué dans le README de FreeBASIC :
sudo apt install gcc libncurses5-dev libffi-dev libgl1-mesa-dev libx11-dev libxext-dev libxrender-dev libxrandr-dev libxpm-dev
Récupérez l'archive sur le site du projet GreatCowBasic et extrayez-le avec unrar (au prompt, entrez le mot de passe « GCB »).
Optional: sudo apt install unrar (maybe unrar-unfree depending on *buntu-Version) wget ‘https://sourceforge.net/projects/gcbasic/files/ _ GCBasic%20-%20Linux%20Distribution/GCB%40Syn_9801.rar/download’ –O GCB.rar sudo unrar x GCB.rar For building GreatCowBASIC, I just compile it without the installation script: cd Great*/Sources/ fbc –exx –v –arch native gcbasic.bas
The installation part works fine, so that you can use the script at least to copy the files to the right place: sudo chmod +x install.sh sudo ./install.sh install Make another softlink (to omit the path prefix later on): sudo ln –s /opt/GCBASIC/gcbasic /bin/gcbasic After that, test if it works: gcbasic /version The installation is done; you are ready to develop your first programs with Great Cow BASIC!
First program Have a look at the recently installed folder /opt/Demos. There you can find plenty of examples of projects already done with GreatCowBasic. ‘First-start-sample.gcb’ is a good starting point for a first physical “hello world”, eg, blinking a LED. An attiny13a has an internal clock up to 9.6 MHz which is set at 1.2 MHz fresh from factory. To change this in order to get faster timing, you would have to change the fuses, which is not within the scope of this article. And unless you know what you are doing, do not change the fuses, because you could brick the chip and render it useless. #chip tiny13a, 1.2 Do Forever PulseOut PortB.4, 100 ms Wait 900 ms Loop This code infinitely lights up the LED for 100 milliseconds, after this period of time the LED stays off for another 900 milliseconds. Save the code in a text editor under blink.gcb. Then compile it, using GreatCowBasic with the integrated assembler, to a hex file that the attiny13a understands. Other supported AVR chips need other options, have a look at the datasheet for individual changes.
gcbasic /O:blink.hex /A:GCASM blink.gcb GreatCowBasic gives some information about the compilation: in blink.lst, there is info about used registers and ram usage, and, in blink.html, you get a comprehensive overview about the compile run. For this example, it shows Chip Model: TINY13A, Program Memory: 32/512 words (6.25%), RAM: 0/64 bytes (0.%). To program the microcontroller afterwards, you need: • 1 breadboard • 6 jumper wires, maybe some short wire bridges • 1 LED, a 5 mm red, yellow, green would suffice • 1 resistor, say 220 ohm • 1 Arduino with ISP-Sketch or any other AVR programmer • (1 10 µF capacitor if using Arduino as ISP, see references) If using an Arduino UNO as ISP; Put the capacitor between RESET and GND (please note the right polarity), then look at the table for how to connect from Arduino UNO to attiny13a.
After preparing the breadboard, the arduino, and the chip, use avrdude to get the hex file to the attiny13a. avrdude –p t13 –P /dev/ttyACM0 –c avrisp –b 19200 –U flash:w:blink.hex This command tells avrdude to flash the hex file with the ArduinoISP on /dev/ttyACM0 with a baudrate of 19200 to the attiny13a (if avrdude complains that the chip identifier does not match, try the –F parameter to force the flash operation, this normally does not brick the chip). After the hex file is written successfully, connect the resistor and the anode (the side with the longer lead) of the LED to PB4 (PIN3). Connect the cathode (with the shorter lead or the flat spot on one side) of the LED with GND. Note: you could write a small shell script which gets the name of the chip and of the hex file so that GCB has a more streamlined workflow of compiling and flashing the microcontroller. For example, see ‘\GreatCowBasic\flash.sh’ in the programs directory, and check the cli parameter section of the help file. I omitted this step and therefore flashing the microcontroller is an extra step for me.
Conclusion For me, the GreatCowBasic compiler offers a convenient and efficient way to program the microcontroller of choice. Additionally, it gives the option to quickly change the microcontroller between PIC and AVR. The project is active, and the developers (and also the community) seem to be very kind and helpful. There are plenty of device drivers and example code for an array of projects which can be built with it (there are drivers for EEPROM, LCD, RTC - too many to list them all). If this article has attracted your attention, try GreatCowBASIC yourself. In further articles, I will show what the attiny13a and GreatCowBASIC have to offer. Drop some comments at https://www.evil-publishing.de/fcm if you wish.
References GreatCowBasic Project http://gcbasic.sourceforge.net/ GreatCowBasic Release notes https://sourceforge.net/p/gcbasic/discussion/579125/thread/d86422f0/ GreatCowBasic help file http://gcbasic.sourceforge.net/help/ GreatCowBasic cli parameter http://gcbasic.sourceforge.net/help/_command_line_parameters.html FreeBASIC https://www.freebasic.net/ attiny13a datasheet http://www.atmel.com/images/doc8126.pdf ArduinoISP https://www.arduino.cc/en/Tutorial/ArduinoISP ArduinoISP > attiny13a https://gist.github.com/dwaq/8239080
BIO Boris holds a bachelor degree in business administration, and works for an insurance company. While not working, he is a family person and enjoys playing with his kids or tinkering with his personal projects.