stknx

KO | EN

gitlite — search

#python #golang #go #android #machine-learning #deep-learning #nodejs #windows #awesome #awesome-list #security #openai #ios #open-source

(★ 23)

demonstrates how to read bytes from stknx chip

stknx Latest Version Download

Download Latest Version (.zip)

// repository documentation

Was this content helpful?

★ 0 (0 ratings)

# Open KNX Lib

## Receive Demo
This code demonstrates how to read bytes from  [STKNX](https://www.st.com/en/interfaces-and-transceivers/stknx.html).

## STKNX vs TP-UART
STKNX tranceives all bytes read from KNX bus to its KNX_RX pin and has neither built-in buffers nor talks a standard UART as it's competetor [TP-UART](http://www.opternus.com/de/siemens/knx-chipset/knx-transceiver-ics-tp-uart-fze1066.html) does.

## Features
  - Retreive startbit by GPIO interrupt (cpu-friendly)
  - Read bits by hardware timer (cpu-friendly)
  - minimal ISR for bitbanging knx bits (cpu-friendly).

## Typical STKNX application circuit
![typical stknx typical application circuit, https://www.st.com/resource/en/datasheet/stknx.pdf](https://raw.githubusercontent.com/mistay/stknx/master/images/stknx.png "STKNX typical application")

## KNX TP1 frame
![knx tp1 standard frame](https://raw.githubusercontent.com/mistay/stknx/master/images/tp1frame.png "KNX TP1 frame")
[reference](https://www.auto.tuwien.ac.at/downloads/knxcalibur/diplomarbeit_fpraus_printed.pdf)

## KNX TP1 control frame
![KNX TP1 control frame](https://raw.githubusercontent.com/mistay/stknx/master/images/knx_controlframe_oscilloscope.jpg "KNX TP1 control frame")

Here you can see a octet read by stknx: CH1 is data from STKNX, CH2 is generated by software in ISR to demonstrate when bits are read (here: 8 bits, 11bits should be read to read start-, parity- and stopbit as well)

This demo-octed is read as: 11100001000 where
- 1: startbit: OK, this should be 1
- 1: D0 (LSB) (inverted)
- 1: D1 (inverted)
- 0: D2 (inverted)
- 0: D3 (inverted)
- 0: D4 (inverted)
- 0: D5 (inverted)
- 1: D6 (inverted)
- 0: D7 (MSB) (inverted)
- 0: (inverted: 1) even paritybit OK ("ones" in databits(D0-D7): 1+1+1 = 3 -> odd-> 1)
- 0: stopbit: OK, this should be 0

So this octet is read as: 01000011 -> inverted 10111100 -> 0xBC

## KNX signal coding
![knx signal coding, KNX specification, free to download on myknx.org. Copyright 1998 - 2013, KNX Association System Specifications](https://raw.githubusercontent.com/mistay/stknx/master/images/knxsignalcoding.png "KNX signal coding")

## Schematic PDF
[Schematic PDF](images/esp32_knx_onewire.pdf "Schematic PDF")

## STKNX / ESP32 board
![STKNX / ESP32 board](https://raw.githubusercontent.com/mistay/stknx/master/images/stknx_onewire_board_photo.jpg "STKNX / ESP32 board")

## Schematic STKNX
![Schematic STKNX](https://raw.githubusercontent.com/mistay/stknx/master/images/schematic_stknx.png "Schematic STKNX")

## Schematic ESP32
![Schematic ESP32](https://raw.githubusercontent.com/mistay/stknx/master/images/schematic_esp32.png "Schematic ESP32")

## Schematic Levelshifter
![Schematic Levelshifter](https://raw.githubusercontent.com/mistay/stknx/master/images/schematic_levelshifter.png "Schematic Levelshifter")

### Requirements
Espressif ESP-IDF framework. No external Libs needed.

* [ESP-IDF](https://github.com/espressif/esp-idf)

### Compile
```sh
$ make
```

### Flash
```sh
$ make flash
```

### Run
```sh
$ make flash monitor
```

### Credits
Special Thanks to [Philipp Aigner](https://www.aignerelektronik.at) and Franz Augernigg

License
----
MIT

stknx

stknx Latest Version Download

Today's picks

Was this content helpful?

Recent Feedback

stknx

stknx Latest Version Download

Today's picks

Was this content helpful?

Recent Feedback

Download README