ALInfrared Tutorial

NAOqi Sensors - Overview | API | Tutorial

See also

Note

This chapter explains how use a robot with remote controls, not the use of the infrared communication between two robots.

Send and receive infrared

The robot as a remote control

To use the robot as a remote control:

  1. Make sure the remote control and the Key name you want to use are declared in the robot web page (Settings), as explained in the section: Set a remote control.
  2. Call the following bound methods with the remote device name and the remote button name as parameters.
/\**
* Function sendRemoteKey is used as an IR remote control.
* @param pRemote: string containing the remote control name
* @param pKey: string containing the button name
\*/
void sendRemoteKey(const std::string& pRemote, const std::string& pKey );

Python example to switch ON your TV:

import naoqi
from naoqi import ALProxy
lirc=ALProxy("ALInfrared","127.0.0.1",9559)
lirc.sendRemoteKey("My_TV_name", "KEY_POWER")

After sending a remote key, the following data will be saved in ALMemory:

Event / Data Type ALMemory Description
Data string “Device/SubDeviceList/IR/LIRC/Remote/Remote/Actuator/Value/” Last remote name sent
Data string “Device/SubDeviceList/IR/LIRC/Remote/Key/Actuator/Value/” Last button name sent

Initialize infrared reception

To be able to receive infrared data you should call the following bound method:

/\**
* Function initReception
* is called to initialize receiving IR information from a remote control or a robot
* @param pRepeatThreshold: number which set the repetition threshold of buttons
\*/
void initReception(const int& pRepeatThreshold);

Python example:

import naoqi
from naoqi import ALProxy
lirc=ALProxy("ALInfrared","127.0.0.1",9559)
lirc.initReception(10);

The parameter pRepeatThreshold is only useful with some remote controls. It avoids thousands of event receptions if the remote control sends the same button frame several times with only one tap! If you don’t care about it, just set it to -1 and the default value will be set or it will keep the previous value if you already called this method:

lirc.initReception(-1);

Control the robot with a remote control

When ALInfrared receives a remote control button, it raises an event containing all information about it. The event name is InfraRedRemoteKeyReceived.

All information about the event are also kept in ALMemory.

The event array and the related data are described in the following table:

Event / Data Type ALMemory Description
Event array “InfraRedRemoteKeyReceived” Contains the 5 following data
Data string “Device/SubDeviceList/IR/LIRC/Remote/LircCode/Sensor/Value/” LIRC hexa code ( online LIRC documentation)
Data int “Device/SubDeviceList/IR/LIRC/Remote/Repeat/Sensor/Value/” Same frame of the button receive in one shot
Data string “Device/SubDeviceList/IR/LIRC/Remote/Key/Sensor/Value/” Name of the button
Data string “Device/SubDeviceList/IR/LIRC/Remote/Remote/Sensor/Value/” Name of the remote (device model)
Data int “Device/SubDeviceList/IR/LIRC/Remote/IrSide/Sensor/Value/” 0 means received on the left eye, 7 means on the right eye.

Python example to receive and display remote buttons event:

alinfrared_receiveremotekey.py

# -*- encoding: UTF-8 -*-

"""
Receive and display remote buttons event:
"""
import naoqi
import time

# create python module
class myModule(naoqi.ALModule):

    def pythondatachanged(self, strVarName, value, strMessage):
        """callback when data change"""
        print "Data changed on", strVarName, ": ", value, " ", strMessage

# call method
try:
    lircProxy = naoqi.ALProxy("ALInfrared")
    lircProxy.initReception(repeatThreshold = 10)
    pythonModule = myModule("pythonModule")
    memProxy = naoqi.ALProxy("ALMemory")
    memProxy.subscribeToEvent("InfraRedRemoteKeyReceived", "pythonModule",
             "pythondatachanged")
except Exception, e:
    print "error"
    print e
    exit(1)
time.sleep(10)
exit(0)

Send data to a robot

It is possible to send 3 kinds of data:

  • a 8 bits unsigned integer (0-255)
  • a 32 bits unsigned integer (0-4294967295)
  • an IP address (e.g. “192.168.0.56”)

To do that use respectively the 3 following bound methods:

/\**
* Function sendIpAddress is called to send an IP address
* @param pIP: string containing an IP address (e.g. "127.0.15.129")
\*/
void sendIpAddress(const std::string& pIP);
/\**
* Function send8 is called to send 1 byte
* @param pByte: Integer containing an byte
\*/
void send8(const int& pByte);
/\**
* Function send32 is called to send 4 bytes
* @param pData_IR: string containing a 4 byte value (be careful it's a string)
\*/
void send32(const std::string& pData_IR);
// OR
/\**
* Function send32 is called to send 4 bytes
* @param pByte1: 1st byte of the 32 bits value
* @param pByte2: 2nd byte of the 32 bits value
* @param pByte3: 3rd byte of the 32 bits value
* @param pByte4: 4th byte of the 32 bits value
\*/
void send32(const int& pByte1, const int& pByte2, const int& pByte3, const int& pByte4);

Python example to send successively the 3 kinds of data:

alinfrared_sendtonao.py

# -*- encoding: UTF-8 -*-

"""
Send an element of each of the 3 supported data type to nao
"""
from naoqi import ALProxy
import time

lirc=ALProxy("ALInfrared","127.0.0.1",9559) # change IP with NAO IP
lirc.sendIpAddress("127.0.0.1") # Send IP address
time.sleep(0.5) # Delay necessary for a reliable transfer
lirc.send8(42) # Send the number 42
time.sleep(0.5)
lirc.send32(0x42, 0x2A, 0x13, 0x0D) # Send one 32 bits number
time.sleep(0.5)
lirc.send32("36757575") # Send one 32 bits number

Warning

It takes around 0.5 seconds to send an byte and around 2 seconds to send 4 bytes or an IP address.

Warning

A delay (~0.5’‘) between every sending is necessary for a reliable transfer.

After having sent a value, the corresponding data will be saved in ALMemory:

Event / Data Type ALMemory Description
Data int “Device/SubDeviceList/IR/LIRC/Data/IP/Actuator/Value/” IP address
Data int “Device/SubDeviceList/IR/LIRC/Data/uInt8/Byte/Actuator/Value/” Unsigned 8 bits integer
Data int “Device/SubDeviceList/IR/LIRC/Data/uInt32/Byte1/Actuator/Value/” 1st byte of the 32 bits unsigned integer
Data int “Device/SubDeviceList/IR/LIRC/Data/uInt32/Byte2/Actuator/Value/” 2nd byte of the 32 bits unsigned integer
Data int “Device/SubDeviceList/IR/LIRC/Data/uInt32/Byte3/Actuator/Value/” 3rd byte of the 32 bits unsigned integer
Data int “Device/SubDeviceList/IR/LIRC/Data/uInt32/Byte4/Actuator/Value/” 4th byte of the 32 bits unsigned integer

Receive data from a robot

When ALInfrared receives data from an other robot, it raises an event containing the data.

All information about the event are also kept in ALMemory.

The event array and the related data are described in the following table:

Event / Data Type ALMemory Description
Event string “InfraRedIpAdressReceived” IP address
Data string “Device/SubDeviceList/IR/LIRC/Data/uInt8/Byte/Sensor/Value/” IP address
Event int “InfraRedOneByteReceived” 8 bits value
Data int “Device/SubDeviceList/IR/LIRC/Data/uInt8/Byte/Sensor/Value/” 8 bits value
Event array “InfraRedFourBytesReceived” array containing the 4 bytes
Data int “Device/SubDeviceList/IR/LIRC/Data/uInt32/Byte1/Sensor/Value/” 1st byte
Data int “Device/SubDeviceList/IR/LIRC/Data/uInt32/Byte2/Sensor/Value/” 2nd byte
Data int “Device/SubDeviceList/IR/LIRC/Data/uInt32/Byte3/Sensor/Value/” 3rd byte
Data int “Device/SubDeviceList/IR/LIRC/Data/uInt32/Byte4/Sensor/Value/” 4th byte

Python example to receive an IP address:

alinfrared_receiveanip.py

# -*- encoding: UTF-8 -*-

"""Receive an IP address"""
import naoqi
import time

# create python module
class myModule(naoqi.ALModule):

    def pythondatachanged(self, strVarName, value, strMessage):
        """callback when data change"""
        print "IP address = ", value, " ", strMessage

# call method
try:
    pythonModule = myModule("pythonModule")
    prox = naoqi.ALProxy("ALMemory")
    prox.subscribeToEvent("InfraRedIpAdressReceived", "pythonModule", "pythondatachanged")
except Exception, e:
    print "error"
    print e
    exit(1)
time.sleep(10)
exit(0)
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