Hardware Description for

ARDUINO™ & AeroQuad© Shield V 1.8/1.9

By Paolo Lavacchini 11/06/2011

Ver. 0.1

Questa è una breve guida all’uso di ARDUINO interfacciata con la “shield” AreoQuad in versione V 1.8/1.9. Il manuale

contiene una cross reference tra i vari connettori e segnali; dal microprocessore Atmel AVR verso il resto dei circuiti e

le terminazioni esterne. Questo in previsione di scrivere una intera libreria di funzioni per l’uso di questo hardware.

Foto e schemi sono di proprietà di ARDUINO™ e AeroQuad© (Carancho Engineering) mentre il resto del materiale è liberamente distribuibile.

Here is a small manual for installation of custom software on hardware ARDUINO and AeroQuad V 1.8/1.9 adapter

board. The manual contains the signals reference between the controllers chip, connectors boards, and the respective

sensors or external wiring. This is for the idea of writing a whole library of functions for using this hardware.

Photos and schematics are property respectively of ARDUINO™ and AeroQuad© (Carancho Engineering), others (my) data are freely distributable.

Board layout ARDUINO™ UNO

View of assembled Arduino PCB

This notes are distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

ARDUINO™ schematics

Features summary of the board with ATmega328 (Atmel)

Operating Voltage 5V

Input Voltage (recommended) 7-12V

Input Voltage (limits) 6-20V

Clock Speed 16 MHz

Digital I/O Pins 14

Analog Input Pins 6

DC Current per I/O Pin 40 mA

DC Current for 3.3V Pin 50 mA

Flash Memory 32 KB

SRAM 2 KB

EEPROM 1 KB

For other data view manufacturer site: http://arduino.cc/en/Main/ArduinoBoardUno

Chip ATmega328

Quick pinout of the “brain” for the quadcopter.

For characteristic and data view Atmel datasheet: http://www.atmel.com/dyn/resources/prod_documents/doc8271.pdf

Arduino UNO connections board layout

Shied AeroQuad V.1.9 (see the new 2 resistor for battery monitor)

USB

PWR

IOH IOL

7 0 7 0

POWER

1 6

ANALOG

1 6

ICSP

1

6

ON

TX

RX

LED

PB5

Board adapter AeroQuad Shield Ver 1.8/1.9

Schematic

Red show the connections to the Arduino board.

The green squares show the embedded sensors.

The pink squares indicate the, likely, user external connections.

For more characteristic and data view: http://www.aeroquadstore.com/default.asp

Isn’t ready yet a new schematics for V 1.9, with two resistor more, to detect the battery level.

Board AeroQuad Shield V 1.8 layout

Red doesn’t mount for quadcopter use.

Blue mount only if you use an ICSP external probe.

ICSP connector

Here the pinout of ICSP connector for the debugging and test.

Warning: reverse of the connector can damage the hardware of Arduino and / or the probe.

My development system

Warning: if you use ATMEL original probe the edge of the connector hits the breakout board (too near).

To avoid to file the connector Atmel bend the pins of the ICSP connection on the Shield to pcb external side.

Cross reference

Cross reference between Arduino to Shield.

IOL connector

Pin shield Processor 328 name Function on Arduino Connect to

1 PD0 RXD RX

2 PD1 TXD TX

3 PD2 INT0 AILERON

4 PD3 INT1 FRONT ESC

5 PD4 T0 THROTTLE

6 PD5 T1 ELEVATOR

7 PD6 AIN0 RUDDER

8 PD7 AIN1 GEAR

IOH connector

Pin shield Processor 328 name Function on Arduino Connect to

1 PB0 ICP AUX1

2 PB1 OC1 BACK ESC

3 PB2 SS RIGHT ESC

4 PB3 MOSI LEFT ESC

5 PB4 MISO LED2 (RED)

6 PB5 SCK (ARDUINO LED) LED1 (GREEN)

7 - - GND

8 AREF (input or output high impedance) A/D reference AREF (don’t use)

ANALOG connector

Pin shield Processor 328 name Function on Arduino Connect to

1 PC0 ADC0 AI 1

2 PC1 ADC1 AI 2

3 PC2 ADC2 AI 3

4 PC3 ADC3 AI 4

5 PC4 ADC4 SDA

6 PC5 ADC5 SCL

POWER connector

Pin shield Name

1 RESET (to Arduino)

2 +3.3V

3 +5V

4 GND

5 GND

6 VIN (connected to VIN Arduino board supply)

I2C explanation of the Shield

Level translator I2C

Sensor communicate with the processor due a I2C serial connection.

I2C, is a serial synchronous link that can be reach a 400 Kbps speed.

In normal application there is a single master that generate the clock for all targets.

Physical connection is based on two wire, the data SDA end the clock SCL.

They are open collector (or drain) and require a pull up resistor to maintain the right value, typical vale are between

4.7K to 10K ohm.

The problem is when the power supply of the target and master are different and they are not tolerant with the

difference.

AeroQuad Shield use a simple breakout board to adapt the level with a resistor divider for the clock and mosfet isolator

for bidirectional line (SDA).

In the BB just only one channel (the channel 1) is used for the conversion.

In the picture master and target are reverse respect the schematic.

LV (3.3V)

HV (5V)

LV (3.3V)

SCL

SDA

SCL

SDA

SCL

SDA

HV (5V)

Master 328

Target 1

Target 2

Soldering shield

Start of building board: the pieces are on the table.

First mount the analogical component and NOT the connectors to Arduino. In this case is very probable a damage of

the plastic case connector with the solder due the low space remaining during the other operation.

To solder the break board use this trick.

Mount the assembly as was soldered and insert the pin in PCB.

Than solder the upper connection, as you view in the photo, with the pins aligned correctly.

Now you have the level translator soldered and you must solder before the ICSP connector until the translator.

Is quite impossible to do the reverse without a damage connector.

ICSP soldered: remember, this is the unique connector mounted up down respect the PCB. View with care the picture

of the connector layout.

Here ICSP soldered on the PCB.

For the other sensor is not possible the previous technique.

They are just one line pins only: you should use other system.

A crocodile is the right instrument to block the pieces and then to solder it.

Board near to be complete.

Use a brush to clean the surface soldered to clean the rest of the flux past with alcohol.

Last connector to mount is the I/O connector.

Will be the communications with the other hardware, receiver and motor.

Is better to use a 90 degrees connector (edge connector) rather than the right type, the cabling will be more slim.

Clean also after this operation with abundant alcohol and brush.

This avoid current leak between adjacent pins of the chips.

Your Shield is now build.

The board under testing: so far so good….