Setting Up Wi-Fi Simple Configuration with NFC on Raspberry Pi

Posted on by max

This post shows steps to setup Wi-Fi Simple Configuration with NFC adapter on Raspberry Pi using nfcpy[1]. The goal is to enable “tap-to-connect” a NFC enabled phone with a Wi-Fi access point [2].

 

Prerequisites (parentheses indicate my environment)

 

Steps
1. Installation
1-1. Install nfcpy.

pip install -U nfcpy

1-2. Verify installation by running the module.

python -m nfc

The output should be like this:

$ python -m nfc
No handlers could be found for logger "nfc.llcp.sec"
This is the 0.13.5 version of nfcpy run in Python 2.7.13
on Linux-4.14.50-v7+-armv7l-with-debian-9.4
I'm now searching your system for contactless devices
** found usb:04e6:5591 at usb:001:004 but access is denied
-- the device is owned by 'root' but you are 'pi'
-- also members of the 'root' group would be permitted
-- you could use 'sudo' but this is not recommended
-- better assign the device to the 'plugdev' group
sudo sh -c 'echo SUBSYSTEM==\"usb\", ACTION==\"add\", ATTRS{idVendor}==\"04e6\", ATTRS{idProduct}==\"5591\", GROUP=\"plugdev\" >> /etc/udev/rules.d/nfcdev.rules'
sudo udevadm control -R # then re-attach device
I'm not trying serial devices because you haven't told me
-- add the option '--search-tty' to have me looking
-- but beware that this may break other serial devs
Sorry, but I couldn't find any contactless device

1-3. As the output suggests, copy line 11 above and execute it.

sudo sh -c 'echo SUBSYSTEM==\"usb\", ACTION==\"add\", ATTRS{idVendor}==\"04e6\", ATTRS{idProduct}==\"5591\", GROUP=\"plugdev\" >> /etc/udev/rules.d/nfcdev.rules'

1-4. Reboot the system.

sudo reboot

1-5. After reboot, run the module again.

python -m nfc

This time, the output should be like this:

$ python -m nfc
No handlers could be found for logger "nfc.llcp.sec"
This is the 0.13.5 version of nfcpy run in Python 2.7.13
on Linux-4.14.50-v7+-armv7l-with-debian-9.4
I'm now searching your system for contactless devices
** found SCM Micro SCL3711-NFC&RW PN533v2.7 at usb:001:004
I'm not trying serial devices because you haven't told me
-- add the option '--search-tty' to have me looking
-- but beware that this may break other serial devs

 

2. Setting up Wi-Fi Simple Configuration
2-1. Download example code [3].

git clone https://github.com/nfcpy/nfcpy.git

2-2. Create NDEF data [4] for Configuration token [5].

./nfcpy/examples/ndeftool.py make wificfg NETWORK_NAME --key PASSWORD -o cfg_token

Note: Replace “NETWORK_NAME” and “PASSWORD” based on your environment.

2-3. Write NDEF data to NFC adapter [6].

./nfcpy/examples/tagtool.py emulate -l cfg_token tt3

 

3. Test
3-1. Enable NFC on the phone.

3-2. Move the phone close to the NFC adapter.

3-3. Allow to connect if the phone asks for permission.

 

 

References
[1] Python module for near field communication – nfcpy
[2] WPS adds NFC “tap-to-connect” for simple set up – Wi-Fi Alliance
[3] nfcpy – GitHub
[4] NFC Data Exchange Format – nfcpy
[5] make wificfg – nfcpy
[6] emulate – nfcpy

 

 

Changing a Bluetooth Device Address on Raspberry Pi

Posted on by max

This post shows how to change Bluetooth device address on Raspberry Pi.

Bluetooth device address (aka BD_ADDR, Bluetooth MAC address) is a 48-bit identifier assigned to each Bluetooth chip. Whether it can be changed is depends on each chip. Fortunately, Raspberry Pi’s on-board Bluetooth chip (Cypress/Broadcom) allows device address change.

 

Assumptions
Raspberry Pi board with on-board Bluetooth chip (e.g. Raspberry Pi3 B+, Raspberry Pi Zero W)

 

Steps
1. Prep
1-1.Install prerequisite package.

sudo apt-get install libbluetooth-dev

1-2. Download the archived file of bdaddr tool. [1][2] 

wget -U firefox http://www.petrilopia.net/wordpress/wp-content/uploads/bdaddrtar.bz2

1-3. Extract the archive file.

bzip2 -d bdaddrtar.bz2 && tar xf bdaddrtar

1-4. Make.

cd bdaddr && make

 

2. Bluetooth Address Change
2-1. Check the original Bluetooth address..

$ ./bdaddr -i hci0
Manufacturer:   Broadcom Corporation (15)
Device address: B8:27:EB:89:DA:DA

2-2. Change Bluetooth device address.

sudo ./bdaddr -i hci0 -r 00:11:22:33:44:55

The result should be like this:

$ sudo ./bdaddr -i hci0 -r 00:11:22:33:44:55
Manufacturer:   Broadcom Corporation (15)
Device address: B8:27:EB:89:DA:DA
New BD address: 00:11:22:33:44:55

Address changed - Device reset successully

2-3. Reset hci device.

sudo hciconfig hci0 reset

2-4. Also, restart bluetooth service.

sudo systemctl restart bluetooth.service

 

3. Verify
3-1. Check the change with bdaddr tool.

$ ./bdaddr -i hci0
Manufacturer:   Broadcom Corporation (15)
Device address: 00:11:22:33:44:55

3-2. Check the change with bluetoothctl.

$ bluetoothctl
[bluetooth]# list
Controller 00:11:22:33:44:55 raspberrypi [default]

 

References
[1] Change your bluetooth device mac-address
[2] Wget: Error 403- Can I get around this?

 

 

Qt Creator Cross Compiling Environment for Raspbian Stretch using QtRpi

Posted on by max


This post shows how to create Qt Creator cross development environment on Ubuntu PC for Raspbian Stretch by using QtRpi. Although QtRpi does not officially support Raspbian Stretch [1], additional few steps make it possible to create the cross development environment for Stretch. (For Raspbian Jessie, please see this post.)

 

Contents
– Assumptions
– Steps
1. Host Preparation (Ubuntu)
2. QtRpi Installation
3. Deploy to Raspberry Pi
4. Raspberry Pi Configuration
5. Qt Creator Configuration
6. Verify Cross Compiling Environment
– Reference

 

Assumptions
Here are some assumptions for the steps below.

  • Ubuntu Linux running on host PC
  • Raspbian Stretch running on target Raspberry Pi
  • Qt Creator running on host PC
  • SSH access from host PC to target Raspberry Pi

In this post, the versions I use are below:

  • Ubuntu 18.04 (host)
  • Qt Creator 4.6.1 (host)
  • Raspbian Stretch April 2018 version running on Raspberry Pi 3 B+ (target)
  • Qt 5.7.0 (target)

 

Steps
1. Host Preparation (Ubuntu)
1-1. Install dependencies.

sudo apt-get update
sudo apt-get install curl g++ gdb-multiarch git unzip zip -y

1-2. Configure environment variable for Qt version. As of writing this, QtRpi supports only 5.6.2 and 5.7.0. [2] 

export QTRPI_QT_VERSION='5.7.0'

1-3. Configure environment variable for Raspberry Pi model. For different models, check the official site.

export QTRPI_TARGET_DEVICE='linux-rpi3-g++'

1-4. Configure environment variable for target IP address.

export QTRPI_TARGET_HOST='pi@192.168.0.5'

1-5. Generate SSH key. Just press enter when you asked about pass phrase.

ssh-keygen

1-6. Copy the key to the target so that you can log in without requiring a password afterwards.

ssh-copy-id $QTRPI_TARGET_HOST

 

2. QtRpi Installation
2-1. On host, download QtRpi from GitHub.

git clone https://github.com/neuronalmotion/qtrpi.git && cd qtrpi

2-2. Then run “init-qtrpi-minimal.sh” script. This will take a while.

./init-qtrpi-minimal.sh

 

3. Deploy to Raspberry Pi
Before start the deployment script, one modification is required since a name of a package has been changed. [3]

3-1. Open the deployment script file.

nano deploy-qtrpi.sh

3-2. Look for the line below and replace “libinput5” with “libinput10”.

ssh $TARGET_HOST 'sudo apt-get install -y libts-0.0-0 libinput5 fontconfig'

After the change, the line should be this:

ssh $TARGET_HOST 'sudo apt-get install -y libts-0.0-0 libinput10 fontconfig'

3-3. Then, run the deployment script.

./deploy-qtrpi.sh --prepare-rpi

 

4. Raspberry Pi Configuration
4-1. Login to Raspberry Pi.

ssh $QTRPI_TARGET_HOST

4-2. Create symbolic links since some libraries has changed names in Stretch. [4] [5] [6] 

sudo ln -s /opt/vc/lib/libbrcmEGL.so /usr/lib/arm-linux-gnueabihf/libEGL.so
sudo ln -s /opt/vc/lib/libbrcmGLESv2.so /usr/lib/arm-linux-gnueabihf/libGLESv2.so

4-3. Copy font files.

cp -r /usr/share/fonts/truetype/dejavu /usr/local/qt5pi/lib/fonts

Note: This step is a workaround for font display. (see troubleshoot in the previous post for detail.)

 

5. Qt Creator Configuration
5-1. Device Configuration
5-1-1. Launch Qt Creator on host.
5-1-2. Navigate to “Tools” > “Options…”
5-1-3. In Options window, select “Devices” from left side bar.
5-1-4. Select “Add…”
5-1-5. Double click on “Generic Linux Device”

5-1-6. Enter information below into “New Generic Linux Device Configuration Setup” window.
Configuration name:

Rpi 3

IP address:  (your RPi’s IP address)

192.168.0.5

Username:

pi

Authentication type:

Key

5-1-7. Click on “Next”, Then “Finish”. Then, it will automatically start “Device Test”.
5-1-8. Click “Close” to close “Device Test” window.

5-2. Debuggers
5-2-1. In Options window, select “Build & Run” from left side bar.
5-2-2. Click on “Debuggers” tab
5-2-3. Click on “Add” button
5-2-4. Put information below:
Name:

GDB multiarch

Path:

/usr/bin/gdb-multiarch

 

5-3. Compilers
5-3-1. Click on “Compilers” tab
5-3-2. Navigate to “Add” > “GCC” > “C”
5-3-3. Enter information below:
Name:

GCC rpi

Compiler Path:

/opt/qtrpi/raspi/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/arm-linux-gnueabihf/bin/gcc

5-3-4. Navigate to “Add” > “GCC” > “C++”
5-3-5. Enter information below:
Name:

G++ rpi

Compiler Path:

/opt/qtrpi/raspi/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/arm-linux-gnueabihf/bin/g++

 

5-4. Qt Versions
5-4-1. Click on “Qt Versions” tab
5-4-2. Click on “Add…”
5-4-3. Navigate the qmake path:

/opt/qtrpi/raspi/qt5/bin/qmake

5-4-4. Enter below as “Version name”.

Qt rpi %{Qt:Version}

5-4-5. Click on “Apply” button

5-5. Kits
5-5-1. Click on “Kits” tab and then “Add” button
5-5-2. Enter (or select) information below:
Name :

Rpi 3

Device Type:

Generic Linux Device

Sysroot :

/opt/qtrpi/raspbian/sysroot

Compiler: C:

GCC rpi

Compiler: C++:

G++ rpi

Debugger :

GDB multiarch

Qt Version :

Qt rpi 5.7.0

5-5-3. Click on “Apply” button, then “OK”.

 

6. Verify Cross Compiling Environment
Let’s check if everything is OK by building a sample project on host and executing it on RPi.

6-1. “File” > “New File or Project”
6-2. “Application” > “Qt Qucick Application”, then click on “Choose…” button.
6-3. Enter project name and click on “Next”.
6-4. Click on “Next” on “Define Build System”.
6-5. Select “Qt 5.7” and click “Next” on “Define Project Details”.
6-6. Check on “Rpi 3” and click “Next” on “Kit Selection”.
6-7. Click on “Finish” button on “Project Management”.
6-8. Open .pro file from the project tree.
6-9. Replace “Default rules for deployment” portion with the two lines below.

target.path = /home/pi/
INSTALLS += target

6-10. Select “Projects” icon on left side bar.
6-11. Click on “Rpi 3” under “Build & Run”.
6-12. Click on “Run” icon on the left side bar.

 

References
[1] QtRpi Requirements – GitHub
[2] What versions of Qt is available? – QtRpi FAQ
[3] deploy-qtrpi.sh “unable to locate libinput5” #69 – qtrpi – GitHub
[4] Games that uses libGLESv2.so doen’t work in raspbian stretch – raspberrypi.org
[5] ArchLinux Qt eglfs – raspberrypi.org
[6] Linking the Application to the Static Version of Qt – Qt Documentation

 

 

Enabling Equalizer on Raspberry Pi using ALSA equal Plugin

Posted on by max


This post shows how to setup a system wide equalizer on Raspberry Pi using ALSA equal plugin. Below are my setup.

  • Raspberry Pi3 B+ with Raspbian Stretch (2018 April version)
  • 3.5 mm plug Speaker

 

Contents
– Assumptions
– Steps
1. Equalizer Plugin Installation
2. ALSA Configuration
3. Play audio
4. Verify Equalizer
– Notes
– Reference

 

Steps
1. Equalizer Plugin Installation

sudo apt-get install libasound2-plugin-equal -y

 

2. ALSA Configuration
2-1. Create .asoundrc.

nano ~/.asoundrc

2-2. Add the lines below, save and close the file.

pcm.!default {
 type plug
 slave.pcm plugequal;
}
 
ctl.equal {
 type equal
}
 
pcm.plugequal {
 type equal
 slave.pcm "plughw:ALSA,0"
}
 
pcm.equal {
 type plug
 slave.pcm plugequal
}

2-3. Reload .asoundrc.

alsactl kill rescan

 

3. Play audio
Play a sample sound file in a loop for testing.

while [ 1 ];do aplay /usr/share/sounds/alsa/Front_Center.wav;done

Note: Press Ctrl+C to exit.

 

4. Verify Equalizer
Adjust the equalizer by using alsamixer command.

alsamixer -D equal

The sound from Raspberry Pi’s speaker should change as you change the equalizer values.

 

Notes
Since Raspbian Stretch, Bluetooth audio is handled by ALSA using bluez-alsa [2]. So if A2DP sink is enabled, this equalizer can be also applied on Bluetooth audio.

 

References
[1] Raspbian: the great Equalizer
[2] Raspbian Stretch has arrived – Raspberry Pi Official Blog

 

 

Streaming Bluetooth Audio from Phone to Raspberry Pi using ALSA

Posted on by max

Update (Jan 8, 2020):
Step 1 has been updated to fix codebay and elba’s problems based on peacekunov’s feedback (Thanks!). Please see the comments for details.

Update (May 22, 2019):
Steps to manually enable A2DP sink role has been added based on Wolfgang and John’s feedback. (Step 1).

This post shows steps to setup Bluetooth audio sink on Raspberry Pi using bluez-alsa. Bluetooth audio sink (A2DP sink) enables Raspberry Pi to receive audio from other Bluetooth devices (e.g. smartphone) and play it through the connected speaker. Below are my setup.

 

Steps
1. Enabling Audio Profile Sink Role
1-1. Open the configuration file for bluealsa service

sudo nano /lib/systemd/system/bluealsa.service

1-2. Search the line starts with “ExecStart” and add a profile option with a2dp-sink as below.

ExecStart=/usr/bin/bluealsa -p a2dp-sink

1-3. Reboot.

sudo reboot

 

2. Bluetooth Pairing and Connection
2-1. Launch BlueZ command line interface.

bluetoothctl

2-2. Setup a pairing agent.

default-agent

2-3. Make the Raspberry Pi discoverable.

discoverable on

2-4. On your phone, search and select your Raspberry Pi from Bluetooth menu.

2-5. Confirm the pairing on both your phone and Raspberry Pi.

Request confirmation
[agent] Confirm passkey 847261 (yes/no): yes

2-6. Authorize A2DP service (first 32 bits: 0000110d). [2] 

Authorize service
[agent] Authorize service 0000110d-0000-1000-8000-00805f9b34fb (yes/no): yes

Note: You may be asked about other services (such as HFP: 0000111E) depending on what services your phone supports. Just answer ‘yes’ to all the services if you are not sure.

2-7. Trust the phone so that Raspberry Pi will automatically accept connections from the phone from the next time.

trust XX:XX:XX:XX:XX:XX

Note: Replace “XX:XX:XX:XX:XX:XX” with your phone’s Bluetooth device address.

2-8. Exit from BlueZ command line interface.

exit

 

3. Audio Routing
3-1. Forward audio from the phone to Raspberry Pi’s output.

bluealsa-aplay 00:00:00:00:00:00

 

4. Verify
4-1. Launch a media player and play some music on your phone. You should be able to hear the music from Raspberry Pi’s speaker.

 

Troubleshoot : Sound Cutting Out
Raspberry Pi’s (3 / 3+ / Zero W) on-board Bluetooth+WiFi combo chip has an issue and the Bluetooth sound cuts out when WiFi is enabled [3]. If you don’t need WiFi, you can just disable the WiFi interface to avoid the sound cutting issue.

sudo ip link set wlan0 down

If you need WiFi, one of the workarounds is to disable the on-board Bluetooth and use a Bluetooth dongle (e.g. Plugable BLE Adapter, Panda Bluetooth 4.0 Adapter) instead. Below is the steps to do that.

1. Open “/etc/modprobe.d/raspi-blacklist.conf”.

sudo nano /etc/modprobe.d/raspi-blacklist.conf

2. Add lines below and save.

blacklist btbcm
blacklist hci_uart

3. Connect Bluetooth dongle on Raspberry Pi’s USB port.

4. Restart the Raspberry Pi.

sudo reboot

 

What’s Next?
If you are interested in controlling Bluetooth audio and showing the song information, please check this out.

 

References
[1] bluealsa: Couldn’t initialize controller thread: Bad file descriptor #149
[2] Service Discovery – Bluetooth SIG
[3] Pi3 bluetooth audio stutters with Wifi enabled