RED Brick¶

Features¶

• Controls other Bricks and Bricklets
• Executes your program directly on the Brick
• Supports nearly all programming languages

Description¶

The Rapid Embedded Development Brick (RED Brick) can control other Bricks and Bricklets. The programming languages C/C++, C#, Delphi/Lazarus, Java, JavaScript, Octave, Perl, PHP, Python, Ruby, Shell and Visual Basic .NET can be executed on the Brick.

A program that controls Bricks and Bricklets can be written and tested on a normal PC or Mac. Afterwards the program can be transferred to the RED Brick by the press of a button and can then be executed without any changes. Multiple programs can be executed simultaneously. The execution of programs can be scheduled (execution on boot up, every hour, etc.) and monitored.

This approach enables a very easy and very fast solution to realize projects. To our knowledge there is no other solution available that is even remotely comparable.

For each supported programming language the Tinkerforge API and commonly used software libraries are pre-installed on the system. Other necessary libraries can be installed manually.

The Brick is equipped with a Micro-HDMI connector, which can be used by programs to show a graphical user interface. A USB 2.0 Host connector can be used to connect USB Wi-Fi adapters, mouses, keyboards, touchscreens and similar.

With an Ethernet Master Extension the RED Brick can be extended by an Ethernet interface. The RS485 Master Extension can be used to connect other remote stacks of Bricks and Bricklets.

Advanced users can use the RED Brick with full access to the underlying Debian system.

An introduction video is available on Youtube:

Technical Specifications¶

Resources¶

• Schematic (Download)
• Outline and drilling plan (Download)
• Linux image and hardware design files (Download)
• 3D model (View online | Download: STEP, FreeCAD)

First Steps / Test your RED Brick¶

With the following instructions you can test your RED Brick. A full step-by-step tutorial regarding the RED Brick can be found here: RED Brick Tutorial.

First install the Brick Daemon and the Brick Viewer software on your PC or Mac. Insert the prepared Micro-SD card into the Micro-SD-Card slot of the RED Brick. The location of the slot and an overview of the different hardware interfaces of the RED Brick is given in the hardware description. You can order a SD card with pre-installed image in our shop. Otherwise you can prepare an SD card yourself, see the copy image to SD card section.

After that your RED Brick is ready to go and can be connected to your PC or Mac with a Mini-USB cable.

If you start the Brick Viewer software and press "Connect". A tab should show up labeled with "RED Brick". Click on it.

On the left side of the tab you see different additional tabs. The "Overview" tab shows information about the CPU load, memory usage and other status information. This view means that your RED Brick works as expected and you can start to upload your programs. See the Brick Viewer section on how to configure the Brick and how to upload your programs.

You can also test the graphical user interface (HDMI). To do so, connect a monitor to the HDMI port and a USB hub with keyboard and mouse to the USB port of the RED Brick. If you power the Brick you can see the LXDE desktop environment booting. After the boot process you should be able to use it as a normal desktop PC.

You can log in to the underlying Linux with user tf and password tf. The tf user is a sudoer.

Brick Viewer¶

This section describes the configuration of the RED Brick with the Brick Viewer software. The RED Brick can also be configured by the RED Brick API (only for power users).

The RED Brick representation in Brick Viewer consists of different tabs, each described in detail below. At the top the UID of the RED Brick, the position in the stack, the name of the used image, number of timeouts and the word System is shown. If you click on it, you can restart the Brick Daemon on the RED Brick and reboot or shut down the RED Brick itself.

Update Tinkerforge Software¶

Starting from Brick Viewer version 2.3.9 it is possible to update Tinkerforge software (Brick Viewer and Tinkerforge bindings) present in the RED Brick. The update process can be initiated from the System menu.

If there are updates available they will be reported.

Upon user confirmation the update process will start.

The only requirement for this update feature is a working Internet connection on the system on which the Brick Viewer is running. The RED Brick doesn't require an active Internet connection for the update feature to work.

Overview Tab (Status Information)¶

This tab is selected by default. It shows the uptime of your RED Brick and the usage of CPU, memory (RAM) and storage. You can see the top processes based on CPU or memory usage and the up- and download speed of the configured network interfaces.

The list can contain the following network interfaces (X is a number, typically 0):

• lo: This is the loopback interface. It is a local interface, used for example for the communication between your program and the local Brick Daemon.
• wlanX : This is a Wi-Fi interface. It is created if you attach a Wi-Fi USB adapter to the USB host connector.
• ethX : This is a Ethernet interface. It is created if you attach a Ethernet USB adapter to the USB host connector.
• tfX : This is the Ethernet interface created if you add an Ethernet Extension on top of the RED Brick.

The data in the overview tab is automatically refreshed every 3 seconds.

Settings Tab¶

The Settings tab is subdivided into several sections.

Network¶

In the Network section of this tab you can configure settings related to networking.

The Current Network Status subsection shows you the status of the configured and currently used network interface. The status is updated automatically every 3 seconds.

Initially the RED Brick is not configured for any interface and will not automatically connect, even if an interface is available. You have to configure an interface in the Configuration subsection. First choose the interface you want to configure. An Ethernet USB adapter will show up as ethX, the Ethernet Extension as tfX and a Wi-Fi USB adapter as wlanX (X is a number). Dependent on the selected interface you will get other configuration options:

• Configure an Ethernet Interface:

  After selecting an Ethernet interface, choose between DHCP or static IP configuration and click the Connect button.

• Configure a Wi-Fi Interface:

  After selecting a Wi-Fi interface press the Scan button to scan for access points. It will take some time to get the scan results.

  Select the desired access point and enter the secret and select between DHCP or static IP address. After that click Connect. Supported Wi-Fi USB adapters can be found in our shop.

Now the RED Brick will automatically connect with the configured interface after a reboot.

Wireless Access Point¶

In the Wireless Access Point section (requires Image >= 1.4 and Brick Viewer >= 2.2.2) of this tab, you can turn the RED Brick into a wireless access point. This section is only available if the Access Point service is activated and you have connected the Wi-Fi USB Adapter to the RED Brick USB port.

If you use Access Point mode, the RED Brick will provide a DHCP and DNS server. It will give devices that connect to it an IP address and provide a domain. You can configure the IP address, SSID, WPA passphrase, DHCP pool, DNS domain and other options that you might expect from an access point.

It is also possible to show the current DHCP leases, which can help you to identify devices that are connected to the RED Brick access point.

If you use the Access Point mode, there is no external network infrastructure necessary. Your smart phone, tablet or laptop can directly connect to the RED Brick.

Mobile Internet¶

In the Mobile Internet section (requires Image >= 1.7 and Brick Viewer >= 2.2.6) of this tab, you can configure the RED Brick to connect to the Internet using a GSM modem. This section is only available if the Mobile Internet service is activated and you have connected the 3G USB adapter to the RED Brick USB port.

Well known mobile network operator configuration parameters can be loaded as presets using the "Provider Presets" button.

After you click the "Connect" the connection will be established. This might take several minutes. It is necessary to enter a SIM Card PIN even if it is not necessary. If you have disabled the PIN on your SIM card, enter an arbitrary PIN.

If Wireless Access Point and Mobile Internet are enabled at the same time then the RED Brick operates as a Wi-Fi router and shares its Internet connection with the connected Wi-Fi clients.

Server Monitoring¶

The server monitoring functionality (requires Image >= 1.6 and Brick Viewer >= 2.2.3) is designed to be used with the Starter Kit: Server Room Monitoring. For further details see the documentation of the kit.

openHAB¶

In the openHAB section (requires Image >= 1.6 and Brick Viewer >= 2.2.3) of this tab you can configure the openHAB service running on the RED Brick. Since Image >= 1.10 and Brick Viewer >= 2.3.11 openHAB2 is used.

This section is only available if the openHAB service is activated.

Using the New and Delete buttons you can create new .items, .rules and .sitemap config files and delete existing config files. Brick Viewer will automatically store the new config files in the correct openHAB config directory depending on the file extension.

After you changed the content of a config file you can click the Apply Changes button to save the changes or click the Discard Changes button to discard the changes. Config files with unsaved changes are marked as (modified).

An openHAB configuration example can be found in the documentation of the Starter Kit: Weather Station.

Brick Daemon¶

In the Brick Daemon section of this tab you can configure settings related to the local Brick Daemon.

The configuration includes listen address, corresponding port, port for WebSockets, authentication secret and several other low level configurations including the LED trigger for the red and green LED.

WebSockets are used by the browser version of the JavaScript bindings to control Bricks and Bricklets.

Date/Time¶

In the Date/Time section you can synchronize the clock of the RED Brick to the clock of your PC. There is no battery on the RED Brick, so the time won't be incremented if the RED Brick is not powered.

If you have a connection to the Internet (trough the Ethernet Extension or a Wi-Fi USB adapter), the date and time are automatically set by NTP. You only have to configure the timezone, which is saved even if the RED Brick is powered down.

If you need the correct time after bootup but you can't guarantee or can't obtain Internet access, you can also use the GPS Bricklet 2.0 or the Real-Time Clock Bricklet 2.0. You can find a small programs on GitHub that could be uploaded to the RED Brick to sync the Linux system time with the GPS time (gps_time program) or the Real-Time Clock's time (rtc_time program).

File System¶

In the File System section (requires Brick Viewer >= 2.2.1) you can expand the file system on the Micro-SD card.

Depending on the image size and the capacity of the Micro-SD card you might not be using the total capacity of the Micro-SD card. In this case expanding the file system will provide you with some extra storage space. If the file system uses less than 95% of the Micro-SD card's size then it can be expanded. To do this follow the instructions in Brick Viewer.

Services¶

In the Services section (requires Image >= 1.4 and Brick Viewer >= 2.2.2) you can enable and disable different services on the RED Brick. If you don't need a web server or a desktop environment on your RED Brick you can disable them and make the RED Brick boot faster. You can also enable the wireless access point mode to directly connect from your smart phone or notebook to the RED Brick.

• GPU: Enables hardware acceleration for graphics. If you enable this, some parts of the RAM are shared with the GPU. If you don't use HDMI we would recommend to disable the GPU.
• Desktop Environment: Starting the desktop environment (LXDE) takes some time, if you don't use it you can disable it to save boot time
• Web Server: The web server is necessary if you want to use web services on the RED Brick. If enabled, it adds about 10 seconds to the boot time!
• Splash Screen: If enabled, a splash screen is shown on startup (during the boot process of the Linux kernel). If disabled you can see the kernel messages.
• Access Point: If access point mode is enabled, you can configure the RED Brick to be an access point in the settings tab.
• Server Monitoring: Enables the Nagios monitoring system, see server monitoring in the settings tab.
• openHAB: Enables the openHAB runtime, see openHAB in the settings tab.
• Mobile Internet: If mobile Internet is enabled, you can configure the a mobile Internet connection in the settings tab.

If you change the services and save the changes, the RED Brick will reboot and the new configuration will be available after the reboot.

Program Tab (Upload and Execution)¶

The documentation of the program tab can be found on a separate site.

Console Tab (Remote Access)¶

If you have attached the RED Brick over its Mini-USB connector to your PC it will also register a USB serial interface. This serial interface can be used to access the Linux shell of the Brick. Select the serial port of the Brick and press Connect. Under Linux the typical interface is /dev/ttyACMX (X is number) under Windows it is Serial Port COMX (X is number) with device name RED Brick Serial Console and on OS X usually shows up as /dev/tty.usbmodemXYZ with XYZ is part of RED Bricks UID. You can log in as user tf with password tf. If you are not sure what the right port is test them all, until you see the shell. It might be necessary to press ENTER to see the prompt.

Below you can see a screenshot of the console executing htop.

A good shell tutorial can be found at linuxcommand.org.

Versions Tab (Daemon, Bindings and Libraries)¶

The versions tab shows version information of the installed Brick Daemon and RED Brick API Daemon as well as the installed Bindings and their associated libraries.

If you want to use other libraries than the installed ones, you can upload them with your program or use the console to install them via apt-get, pip, pear, npm or similar package managers. The listed package managers are all installed in all RED Brick images.

Extensions Tab (Configure, Manage)¶

Two Master Extensions are supported by the RED Brick: Ethernet Extension and RS485 Extension.

Changing the settings on either of the Extensions will restart the Brick Daemon on the RED Brick, i.e. your RED Brick tab in the Brick Viewer will disappear for a few seconds and then pop up again.

Ethernet Extension¶

Only the MAC address of the Ethernet Extension can be changed here. Since the Ethernet Extension shows up as a normal network interface in the underlying Linux, you can configure it like any other network interface through the Settings Tab.

RS485 Extension¶

The configuration of the RS485 Extension is the same as it can be done through a Master Brick. See the RS485 Extension documentation.

The supported baudrates that can be used on the RED Brick are 500000, 250000, 166666, 125000, 100000, 83333, 71428, 62500, 55555, 50000, 45454 or 41666 baud.

Import/Export¶

The Import/Export tab (requires Brick Viewer >= 2.2.2) allows to import/export programs and system logs.

System Logs¶

Choose a log file and click Refresh to download it from the RED Brick and show it in the viewer. With the Save button you can save it on your disk.

Import¶

Choose a file you previously exported (see below) and select the programs you want to import to your RED Brick. Press Import to upload the selected programs.

Export¶

In the export tab you can select the programs that you want to export from the RED Brick. Press Export to save them on your disk.

The export file will contain the configuration of the program, all of the program files as well as the logs that have been accumulated. If your program is running and continuously writing files, you may want to shut the program down before you export it. Otherwise you might export the program with a file that is only partly written.

With this option programs can be exported and on a different RED Brick be imported (see above).

RED Brick Web Interface¶

If your RED Brick is equipped with a Wi-Fi USB adapter, an Ethernet Extension or has other network connectivity, you can access a web interface. The web interface is available at the IP address of the RED Brick or the hostname (red-brick by default).

The RED Brick web interface shows the installed programs. You can view the logs and configs of the programs as well as the uploaded binaries. Since Image version 1.6 the available openHAB sitemaps and a link to the server monitoring website are included as well.

Besides the default web interface you can also put your own web interfaces on the RED Brick. Currently we support web applications written in HTML/JavaScript, Python and PHP. If you upload an index.py, index.php or index.html, the respective file will be used as directory index for the binary folder.

Example to clarify: If you want to write a PHP website that controls Bricks/Bricklets you can upload your PHP program EXAMPLE with id EXAMPLE-ID that includes an index.php as starting point. If you now go to the RED Brick web interface and click on the "Bin" button for the newly created EXAMPLE program, you will get a link to /programs/EXAMPLE-ID/bin, which will directly execute the index.php if opened since it will act as index for this directory.

This way you can easily implement a web page that shows environment information gathered from Temperature/Barometer/Humidity Bricklets or you can have a web page with buttons that control Relay Bricklets, etc.

With the RED Brick it is super simple to write web applications that can control hardware.

<script src="/Tinkerforge.js" type='text/javascript'></script>

from flask import Flask       # Use Flask framework
application = Flask(__name__) # Function "application" is used by Apache/wsgi
app = application             # Use shortcut for routing

@app.route('/')
def index():
    return '<html><body>Hello World!</body></html>'

from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_temperature import Temperature

# ...

<?php $greeting = 'Hello World!'; ?>

<html>
 <head>
  <title>PHP Example</title>
 </head>
 <body>
  <p><?php echo $greeting; ?><p>
  <p><?php phpinfo(); ?><p>
 </body>
</html>

require_once('Tinkerforge/IPConnection.php');
require_once('Tinkerforge/BrickletTemperature.php');

// ...

RED Brick Software Image¶

The RED Brick software image is based on Debian and is stored on a Micro-SD-Card. Previously the image was available in two different flavors: The "full" and the "fast" image. Since image version 1.4 there is only one image (previously known as the full image) with configurable services (desktop environment, web server, wireless access point, etc.) that allow to customize your image for your individual requirements.

The image comes with a driver for the GPU and all necessary graphical user interface libraries. If enabled, it boots an X server and the LXDE desktop environment with auto login. If the program you run on the RED Brick uses a graphical interface it will show up on the desktop. The screen resolution should automatically adapt to the preferred resolution of the connected HDMI monitor. If you want to change it, you can configure the screen resolution through LXDE. You don't have to use the HDMI port and can execute non graphical programs on this image.

New software can be installed. See the description of the versions tab on how to install new software.

A list of pre-installed programming language libraries is available: Installed library versions.

If you want to log into the Linux system by command line or LXDE, the standard user is tf with default password tf. The user is a sudoer, i.e. you can get root access by calling:

sudo -s

The images can be downloaded from the download page.

sudo tf-set-resolution hdmi mode <mode-number>

dmesg | egrep "(PCLK=|disp clks:)"

Example Programs¶

Several example programs are available on GitHub:

• Set GPS time as system time: If you can't use NTP (i.e. the RED Brick does not have Internet access), you can use the GPS Bricklet to set a proper system time.
• Set Real-Time Clock Bricklet's time as system time: If you can't use NTP (i.e. the RED Brick does not have Internet access), you can use the Real-Time Clock Bricklet Bricklet to set a proper system time.
• Synchronize system time via web browser: If you can't use NTP or a GPS Bricklet or a Real-Time Clock Bricklet to set a proper system time, you can manually synchronize it using your web browser.
• Get humidity callback reading via SMS: This example demonstrates how Bricklet callback values can be reported via SMS if you have a GSM modem connected to the RED Brick.
• Get GPS location from SMS request: This example demonstrates how GPS location can be reported via SMS if you have a GPS Bricklet and a GSM modem connected to the RED Brick.

Hardware Description¶

FAQ¶

• Q: I connected the RED Brick to my Linux PC. Why is there no /dev/ttyACM0 device to access its serial console?

  A: The cdc_acm driver has to be loaded for this to work.

• Q: The red and blue LED are on. But nothing happens.

  A: The RED Brick is not booting. Please check your Micro-SD card.

Known Issues¶

Second Master Extension does not work all the time (solved)

The kernel configuration in image version 1.0 is erroneous. This results in the second Master Extension not working all the time if two Extension are used at the same time.

Since image version 1.1 the kernel configuration is fixed and this problem does not occur anymore.

C# program crashes on startup (solved)

Image version 1.0 contain C# bindings, that were compiled for CLR version 4. With this C# bindings Mono crashes if the C# program was compiled for CLR version 2:

Missing method .ctor in assembly /usr/lib/Tinkerforge.dll, type System.Runtime.Versioning.TargetFrameworkAttribute

This problem can be avoided by compiling the C# program for CLR version 4 or by adding the following line to the Mono options in C# configuration of the program:

--runtime=v4.0

This problem only affect image version 1.0. Since image version 1.1 the C# bindings are compiled for CLR version 2 again, which fixes the problem.

Stack with NFC/RFID Bricklet on RED Brick does not show up in Brick Viewer (solved)

Problematic setup: Master Brick with NFC/RFID Bricklet and any other Bricklet on top of a RED Brick. In this cases on the RED Brick shows up in Brick Viewer but none of the Bricks and Bricklets in the stack.

The problem is caused by an incompatibility in the NFC/RFID Bricklet plugin version 2.0.0. The incompatibility is fixed in plugin version 2.0.1.

FPC (Delphi/Lazarus) Library not available on RED Brick (solved)

Unfortunately we introduced a bug in the Delphi/Lazarus Bindings through a last-minute change. Because of the bug there is no FPC Library installed on the RED Brick image (version 1.0 and 1.1). This will be fixed in version 1.2, in the meantime you can fix this issue through the console with the following commands:

sudo su
# password = tf

cd /usr/tinkerforge/bindings/delphi/source/
sed -i -e 's/BrickRED//g' Makefile.fpc
export FPCDIR=/usr/lib/fpc/`ls /usr/lib/fpc/ | grep -E [0-9].[0-9].[0-9] | head -n1`
fpcmake
make
make install

Now the FPC Library should be installed properly and everything should work as expected!

The problem only affects image version 1.0 and 1.1, it is fixed since image version 1.2.

No name resolution (solved)

In Image version 1.2 there is no name resolution (DNS) by default. You can fix this through the console:

sudo su
# enter password tf

echo "nameserver 8.8.8.8" > /etc/resolv.conf

The problem only affects image version 1.2, it is fixed since image version 1.3.

Ethernet Extension shows up in Extension tab but not in network settings (solved)

In Image version 1.4 the RED Bricks may have problems finding the driver for the Ethernet extension. If you encounter this problem you can fix this through the console:

sudo su
# enter password tf

ln -s /lib/modules/3.4.103+/kernel/drivers/net/ethernet/wiznet/w5x00.ko /lib/modules/3.4.90+/kernel/drivers/net/ethernet/wiznet/

The problem only affects the RED Brick Image with version 1.4, it is fixed since image version 1.5.

Display resolution cannot be changed (open)

In Image version 1.10 the tf-set-resolution tool isn't available anymore, because of the Kernel upgrade vom 3.4 to 4.13. Therefore, the resolution of a connected display cannot be changed at the moment.

openHAB2 reports missing OSGi packages (open)

In Image version 1.10 openHAB2 is used. After its first activation it installed some OSGi packages on its own. If this installation is aborted by a restart of the RED Brick, or if no Internet connection was available, then openHAB2 can end up in this situation.

This problem can be avoided by making sure that an Internet connection is available if the openHAB service is enabled for the first time and that the RED Brick is not restarted during the installation process. The progress of the installation process can be monitored on the opneHAB webinterface.

History¶

The development of the RED Brick took almost a year and is documented in several blog posts:

• Tinkerforge goes Stand-Alone aka RED Brick
• RED Brick circuit boards arrived
• RED Brick news
• RED Brick: Does it work?
• RED Brick Software Infrastructure
• RED Brick in EMC laboratory
• RED Brick status report
• The RED Brick Countdown has started

Programming Interface¶

The RED Brick API is meant to be used by the Brick Viewer to implement the offered functionality (getting status information, managing programs etc.). Normal users will not need to use this API, it may only be interesting for power users.

See Programming Interface for a detailed description.