Admin at 23:30, 24 November 2012

2012-11-24T23:30:30Z

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Presentation Notes for the Microcontroller Introduction at Westlakes Amateur Radio Club

Data sheets

* [[Datasheets]] Link to various datasheets

Hardware setup:

* connection diagram
* batch/script files
* avrdude

Avrdude program script

* Windows

<pre>
@echo off

set PROJECT=blinkled
set SPEED=16000000UL
set PORT=\\.\USBSER000
set GCC_DEVICE=attiny85
set PGM_DEVICE=t85
set PGM_PROTO=avrispv2
set GCC_OPTIMISATION=-Os
set AVRTOOLS=C:\winavr-20100110\bin

echo compile program
avr-gcc -g %GCC_OPTIMISATION% -Wall -mcall-prologues -DF_CPU=%SPEED% -mmcu=%GCC_DEVICE% -c -o %PROJECT%.o %PROJECT%.c

echo create object file
avr-gcc -g %GCC_OPTIMISATION% -Wall -mcall-prologues -DF_CPU=%SPEED% -mmcu=%GCC_DEVICE% %PROJECT%.o -o %PROJECT%.obj

echo convert object file to hex file
avr-objcopy -R .eeprom -O ihex %PROJECT%.obj %PROJECT%.hex

echo write program to chip
avrdude -F -c %PGM_PROTO% -P %PORT% -p %PGM_DEVICE% -U flash:w:%PROJECT%.hex

echo avr-list output:
echo ----------------
%AVRTOOLS%\avr-size -C --mcu=%GCC_DEVICE% %PROJECT%.obj > %PROJECT%_avr-size.txt

type %PROJECT%_avr-size.txt

pause
</pre>

* Linux

Demo Programs for the ATtiny85:

* Blink led

<pre>

/*

Demo program: blinkled.c

This program continously loops, bringing PB4 high and low with one-second intervals.

ATtiny85

+--- ---+
(RST) PB5 -|1 |_| 8|- VCC
PB3 -|2 7|- PB2 (SCK)
+---|<|------ PB4 -|3 6|- PB1 (MISO)
| led +-- GND -|4 5|- PB0 (MOSI)
| | +-------+
+--/\/\/--+
1k

Pololu programming cable pinout (top view)

+---+
---------------- gnd |o o| rst
ribbon cable mosi |o o| sck
-----red-------- vdd |o o| miso
+---+

NOTE: The T85 must be externally powered with 5V (4.5V does NOT work!)
A t85 driving a standard 2x16 LCD without backlit LED on draws
about 8.5mA so with 100mA to spare on a USB port you could consider
grabbing 5V from the Pololu programmer. The 5V pin on the
programmer is labeled: 'VBUS (+5V)'

*/

#include <avr/io.h>
#include <util/delay.h>

#define LED PB4 // Define ext led pin on PB4
#define OUTPUT 0
#define INPUT 1
#define LOW 0
#define HIGH 1

void pinMode(int pin,int state)
{
if (state == OUTPUT)
{
(DDRB |= (1 << pin));
} else {
(DDRB &= ~(1 << pin));
}
}

void digitalWrite(int pin, int state)
{
// make sure port is set to output
DDRB |= (1 << pin);

if (state == HIGH)
{
(PORTB |= (1 << pin));
} else {
(PORTB &= ~(1 << pin));
}
}

int main( void )
{

pinMode(LED,OUTPUT); // Set output direction on LED

while ( 1 )
{

digitalWrite (LED,HIGH);
_delay_ms(1000);
digitalWrite (LED,LOW);
_delay_ms(1000);

}

return 0;

}
</pre>

* Read push button state
* Analog to Digital
* PWM (pulse width modulation)

Web links:

(AVR)
* http://www.atmel.com/products/microcontrollers/avr/default.aspx Atmel 8 and 32-bit microcontrollers
* http://www.pololu.com/catalog/product/1300 Pololu, a basic USB-based AVR ISP Programmer
* http://winavr.sourceforge.net/ WinAVR, AVR-GCC for Windows
* http://www.nongnu.org/avrdude/ AVRdude, ROM downloader/updater
* http://www.engbedded.com/fusecalc AVR Fuse Byte calculator
* http://www.rickety.us/2010/03/arduino-avr-high-voltage-serial-programmer/ ATtiny fuse byte resetter
* http://www.arduino.cc/ Arduino, prototyping platform
* http://www.avrfreaks.net/ AVRfreaks, forum for Atmel microcontrollers

(Other)
* http://www.raspberrypi.org/ Raspberry Pi, ARM-based Single Board Computer (SBC)
* http://www.sparkfun.com/ Sparkfun, USA-based electronics store
* http://littlebirdelectronics.com/ Littlebird Electronics, reseller (and more) for Sparkfun products
* http://www.robotgear.com.au RobotGear, reseller (and more) for Sparkfun products and Pololu programmer
* http://www.diptrace.com/ Diptrace, printed circuit board (PCB) design software
* http://oshpark.com/ OSH Park (previously dorkbotpdx), inexpensive manufacturer for low-volume PCB prototyping
* http://www.gabotronics.com/development-boards/xmega-xprotolab.htm XprotoLab, a tiny oscilloscope and wave form generator (AWG)

Mcu-notes-01 - Revision history

Admin at 23:30, 24 November 2012