Week 13: Network and Communication

The assignment:

1. Group assignemt:LINK

2. Individual assignment: Design, build, and connect wired or wireless node(s) with network or bus addresses and a local interface

What I learned in class

Wired networks can be set up in different ways.

Serial vs parallel

Serial interfaces stream their data with a reference signal, one single bit at a time. These interfaces can operate on as little as one wire, usually never more than four:

Synchronous vs. Asynchronous

“Asynchronous” (not synchronous) means that data is transferred without support from an external clock signal. This transmission method is perfect for minimizing the required wires and I/O pins, but it does mean we need to put some extra effort into reliably transferring and receiving data.

RX/TX

By RX/TX we know the most common way of serial communication. It requires only two wires, appart from a common ground

UART

UART stands for Universal Asynchronous Receiver/Transmitter and is the piece of hardware in charge of managing the data.

What I did

For the assignment for this week I wanted to set up I2C communication The I2C protocol is a protocol intended to allow one or more “children/slave” digital integrated circuits (chips) to communicate with one or more “master/ parent”. It is only meant for short distance communications within a single device. I2C is a convenient way of setting up communication because:

  • It allows for several masters

  • It allows for several slaves

  • The number of wires does not change

    • I2C bus consists of two signals (apart from VCC and GND): SCL and SDA. SCL is the clock signal, and SDA is the data signal. In class we connected 2 Barduinos (ESP32-S3) with wires. To make the 2 boards communicate I needed to find out the SDA and SCL pin to create wired communication between them. After checking the pinout we used pin 8 and pin 9 and GND. See pinout:

    Pinouts

    Pinouts

    Then we decided for 1 Barduino to be “parent/master” and the other to be “child/slave”. We created the code together in class, installed the necessary library: “wire.h”and where then able to upload code that made it possible to do a Blink test and commuicate back and forth between the 2 boards

    (See the modyfied code for parent and child below)

    After succeding with this exercise I tried to make a connection between a board that I had made earlier and a Barduino. The board I had made has a Attiny1614 on it. See pinout here:

    Pinouts

    I used the same workflow as we did in class. But at first nothing happened. I noticed that the soldering on my board was poor and with help from my instructor I located where the problems were and resoldered. I uploaded the code again where the Attiny1614 was “parent” and the Barduino was “child”. Now the blink code worked.

    Here are the files with the code for "Parent" and "Child"

    Parent

    Child