about // doc

AVR & Arduino Notes

Created: Feb, 2014

Last modified: Oct, 2015

AVR characteristics

Max voltage, current and CPU frequency:

AVR CPU freq 1

AVR CPU freq 2

AVR registers

IO stuff: DDRx sets the direction, 0 for input and 1 for output for each bit; PORTx sets the output of each pin, 0 for low and 1 for high for each bit; PINx reads the digital input, 0 for low and 1 for high for each bit. Example:

DDRB = (1<<DDB0)|(1<<DDB4)|(1<<DDB5)|(1<<DDB7);
PORTD = (1 << PD0)|(1 << PD3)|(1 << PD6);
if (PINC == 0x01) {...};  // input is usually used in condition statement

Arduino General

How to install an Arduino library on Linux

Make Arduino low power

Some posts below may help:

How to program Arduino Pro Mini from Arduino IDE

Connect VCC(VBUS), GND, TX and RX pins to another USB to serial converter (such as CH340) correctly.
Open IDE, “Tools” –> “Board” –> choose “Arduino Pro or Pro mini”, and “Tools” –> “Processor” –> choose “Atmega328, 3.3V, 8MHz”.
When ready to upload code, kee pressing the reset button on Arduino pro mini, and then click “upload” in IDE. Release the button until “uploading” shows up in the IDE.
One can use Arduino IDE to write AVR C code directly (don’t need to be restricted to setup() and loop() Arduino style functions).
Haven’t been successful in downloading code to AVR using Arduino ISP approach. Use USB-serial adapter to do that for now.
The AVR libraries headers can be found at “C:\Program Files (x86)\Arduino\hardware\tools\avr\avr\include”.

Troubleshooting

Problem: Arduino IDE cannot connect to serial “/dev/ttyACM0” (Arduino Uno)

Solution: After trying various things, it works after I changes the connection from a USB 2 to USB 3 port.