Arduino Notes

Prime Links

Arduino - official home page
Arduino Playground
Arduino Source - GitHub

Timers and Pins

Timer0 - Used for millis and delay; also analogWrite on pins 5 and 6
Timer1 - analogWrite functions on pins 9 and 10; also driving servos using the Servo library
Timer2 - analogWrite functions on pins 3 and 11

Tone library

On a standard Arduino board, the first tone will use timer 2 (so PWM on pins 9 and 10 will not be available);
the second tone uses timer 1 (preventing the Servo library and PWM on pins 11 and 12 from working).
On a Mega board, each simultaneous tone will use timers in the following order: 2, 3, 4, 5, 1, 0.”

Servo Library

The Servo library uses the same timer as analogWrite on pins 9 and 10, so you can’t use analogWrite with these pins when using the Servo library.

Arduino Pro Mini

Official Arduino Pro Mini site
Arduino USB-to-Serial Tutorial - Programming the Pro Mini - great in-depth tests with various USB to serial devices by Julian Ilett.

USB-to-Serial Programming

Pin Connections as described on weworkweplay:

Connect USB DTR to Arduino GRN, aka DAW on some boards
Connect USB RXD to Arduino TXD
Connect USB TXD to Arduino RXI
Connect USB 3.3V to Arduino VCC
Connect USB Ground to Arduino BLK, aka GND on some boards

Arduino Nano

See the Official Arduino Nano site for board details.

Power

Specs:

Operating Voltage (logic level) 5 V
Input Voltage (recommended) 7-12 V
Input Voltage (limits) 6-20 V

The power source is automatically selected to the highest voltage source from one of:

the Mini-B USB connection
6-20V unregulated external power supply (pin 30)
5V regulated external power supply (pin 27)

Pins

Getting Arduino Nano to work on a Mac

see the offical MacOSX setup notes
if necessary, install the FTDIUSBSerialDriver_v2_2_18.dmg
see the arduino forum - general discussion and updates on the issue

Arduinos using the CH340G serial chip

Examined Arduino Nano and confirmed it is using the CH340G serial chip, which MacOSX Yosemite and later does not recognise by default.

See "How to use cheap Chinese Arduinos that come with with CH340G / CH341G Serial/USB chip" - a great guide.

Updated driver (Sierra-compatible) is available at github.com/adrianmihalko/ch340g-ch34g-ch34x-mac-os-x-driver

There also seems to be a professional drive kit available (at cost) from https://www.mac-usb-serial.com/