TXT 4.0 Internals and Programming book: updated, corrected, and published

[david_adams]

Dear all,

This is to let you know that the TXT 4.0 Internals and Programming book is now available as premium full-colour paperback from Amazon.

Compared to the editorial draft from a couple of weeks ago, the published version has a few hundred small corrections (typos, spelling errors, etc.), a new example about managing multiple extension controllers from a Python program (section 22.3.11), and small updates to some of the figures.

Corrected and updated draft versions for personal use are again available as free PDF downloads from:

https://tarma.com/embedded/txt4book

The book covers most aspects of the hardware and software internals of the fischertechnik TXT 4.0 controller, along with chapters about application development for that controller. Find out:

• Why the counting inputs C1-C4 can only count 500 pulses per second instead of the 1000 per second that fischertechnik claims (sections 8.2 and 24.3.5)
• How the resistance and NTC temperatures are calculated for inputs I1-I8 (sections 7.2.4 to 7.2.6)
• How the ultrasonic distance sensor protocol works (section 7.4)
• What the output signals on O1-O8 / M1-M4 look like under various loads (sections 9.4.1 to 9.4.6)
• How to switch between boot partitions A and B (section 5.4.5)
• How to obtain root access and add yourself to the sudoers list (sections 2.4 and 2.4.1)
• How the various interface protocols work: CAN (chapter 11), I2C (chapter 12), USB (chapter 13)
• How extension controllers are discovered and registered (section 11.3)
• How to program each sensor and actuator, from micro switches and LEDs to encoder motors, each I2C sensor, and the USB colour camera (chapters 23 to 29)
• How to program mecanum vehicle movements efficiently (section 26.4.6)
• How the image processing steps by the ball detector (section 30.3.6), line detector (section 30.3.9), and motion detector (section 30.3.11) algorithms work.

The book combines theoretical background with practical examples and a wealth of information and technical data about the TXT 4.0 controller and the fischertechnik sensors and actuators.

• The internal operation of the TXT 4.0 controller: the STM32MP157 SoC and its CPUs, peripherals, storage, and the way the Linux and FreeRTOS operating systems are used.
• The details of the embedded firmware and how it implements the front-panel I/O connections: the universal inputs I1-I8, the counter inputs C1-C4, the general outputs O1-O8 and motor outputs M1-M4, and the servo outputs S1-S3.
• The way that multiple TXT 4.0 controllers are connected in an extension chain using the CAN FD protocol within the EXT1-EXT2 connectors and how they interact with each other.
• The I2C interface within the EXT1-EXT2 connectors and how it is used to communicate with I2C-based sensors. The sensors themselves are discussed separately.
• The USB1 host and the USB2 device ports and how each of them, and the USB protocol itself, operates in the context of the TXT 4.0.
• A complete treatment of all current fischertechnik sensors and actuators: their technical data, operation, and programming.
• A complete programming reference for the C client libraries TxtControlLib and ftlock.
• A complete programming reference for the fischertechnik Python class library.

Enjoy,
-- David

[mario]

hello mr Adams,

Thank you very much to clarify up the TXT4.0 Controller !!!
What a big job !!!!
With your book I had hope to solve my print problem.
Even with your python examples the print function will not print out the result in the Console ??
Mysteries of Python ???
What can be the reason. Is it possible that ( in my case) the built_in print function does not exist ??

kind regards
Rien van Harmelen( NL)

[david_adams]

Hello Rien,

Thanks for reading the TXT 4.0 book; I hope that you will find it useful.

As to the Python mystery: there is usually a rational explanation for this. The print function is built into the Python runtime system, so it is available on any Python installation. A simple program such as the following should be enough for testing:

Code: Alles auswählen

print('Hello, world!')

Nothing else is needed; this should print the text on the standard output.

What the standard output is, depends on the context: if you run this from an SSH terminal session, you should see it as output in the terminal. Running from Robo Pro Coding, it should appear in the Console pane. Because you mention the Console, I assume that you use the latter.

Can you send me the program that you are trying to make print its output? You can use a private message or an email directly to me if you prefer (use the Contact: speech bubble to the right of this post); that is more likely to reach me in a timely manner than normal forum posts.

Kind regards,
-- David