JTAGulator: Find IoT-Device's UART interface
Revision as of 11:44, 2 December 2019 by Jostrowski (talk | contribs)
Summary
Description on how to find the UART interface of an IoT-Device. In this example the "smart" alarm system Technaxx WiFi smart alarm system starter kit TX-84 will be used.
Requirements
- Read subsection 'Finding UART' of JTAGulator: Introduction to understand the basic commands available.
- JTAGualtor
- Technaxx WiFi smart alarm system starter kit TX-84 or some other device
UART explained
UART stands for Universal Asynchronous Receiver/Transmitter and is a communication specification between to devices and allows for a serialized asynchronous communication.
- UART consist out of
- TX .. Transmit
- RX .. Receive
- Vcc .. Supply Voltage (optional)
- Gnd .. Ground 0V (optional)
whereas the RX from on device is connected to the TX from the other device
The two devices should have the same ground and same Vcc
Data transmission
- A UART packet looks as followed
- - Start Bit: A connected non sending data-line is kept at the Vcc voltage. When one party wants to send data it indicates it by pulling the data-line to ground.
- - Data Frame: The actual data consisting of 5 to 9 bits is sent over the line.
- - Parity: To detect transmission errors a checksum is appended to the packet. There are different modes: total of all even bits, total of all uneven bits.
Step 1
Enter these commands in the shell
echo foo echo bar
Step 2
Make sure to read
- War and Peace
- Lord of the Rings
- The Baroque Cycle
Used Hardware
Device to be used with this documentation Maybe another device to be used with this documentation
Courses
- A course where this documentation was used (2017, 2018)
- Another one (2018)