W14 - Networking and communications¶

1. Weekly Assignments ( -> what I did this week )¶

Individual assignment
design, build, and connect wired or wireless node(s) with network or bus addresses.

( -> I tried I2C communication by using ATtiny44 board which I made in week08, also tried ESP32 with iPhone via wifi. )

Group assignment
Send a message between two projects.

( -> In accordance with Homma-san’s instruction ( fablab Kannai), I tried MQTT (ESP32-AWS IoT) )

	test	device1	pin	network	device2	pin
1	I2C	Arduino UNO (master)	A4(SDA) A5(SCL)	I2C	Arduino UNO R3 (slave)	A4(SDA) A5(SCL)
2	I2C	Arduino UNO (master)	A4(SDA) A5(SCL)	I2C	ATtiny44 (slave)	PA6(SDA) PA4(SCL)
3	http	Macbook Pro	none	(wifi)	Barduino (ESP32)	(wifi)
4	Blynk	iPhone	none	(wifi)	Barduino (ESP32)	(wifi)

Have you?¶

Questions from “Fab Academy 2020 Assignments and Assessment ¶

Networking and Communications

( -> my answers )¶

Linked to the group assignment page ( -> yes )
Documented your project. ( -> yes )
Documented what you have learned from implementing networking and/or communication protocols ( -> yes )
Explained the programming process/es you used. ( -> yes )
Outlined problems and how you fixed them ( -> yes )
Included design files (or linked to where they are located if you are using a board you have designed and fabricated earlier) and original code. ( -> yes )

2. Group Assignment Link¶

MQTT (ESP32 as a pubsub client - AWS IoT as a MQTT broker) by Tatsuro Homma (fablab Kannai 2020)

I joined this MQTT testing using my Barduino board from my site.

3. Works, steps and some details¶

1) Test 1¶

	test	device1	pin	network	device2	pin
1	I2C	Arduino UNO (master)	A4(SDA) A5(SCL)	I2C	Arduino UNO R3 (slave)	A4(SDA) A5(SCL)

“slave” MC sends the count up to “master” MC ( serial plotter on “master” MC is shown in the video )

“I2C-master.ino”

#include <Wire.h>

void setup()
{
    Serial.begin(9600);
    Wire.begin(); // set this MC as master
}

void loop()
{
    // request bytes from a slave device
    Wire.requestFrom(0x1E, 1); 

    while(Wire.available())
    { 
         //Reads a byte that was transmitted from a slave device
        byte num = Wire.read();
        Serial.println(num);
    }

    delay(500);
}

“I2C-slave.ino”

#include <Wire.h>
void setup()
{
  // set this MC as slave, address 0x1E
  Wire.begin(0x1E);
  // Register a function to be called
  // when a master requests data from this slave device.
  Wire.onRequest(send_count);
}

byte count = 0;

void loop()
{
    delay(500);
}

void send_count()
{
    Wire.write(count);
    count++;
}

2) Test 2¶

	test	device1	pin	network	device2	pin
2	I2C	Arduino UNO (master)	A4(SDA) A5(SCL)	I2C	ATtiny44 (slave)	PA6(SDA) PA4(SCL)

codes are same as Test 1.

“slave” MC sends the count up to “master” MC ( serial plotter on “master” MC is shown in the video )

3-1) Preparation for Test 3¶

nodeMCU32S , LED blink test

( Because this was my first experience that I used ESP32, I tried this dev kit before Barduino. )

I installed “CP210x USB - UART” driver so that USB port is recognized by MacBook.

CP210x USB to UART Bridge VCP Drivers

CP210x USB to UART Bridge VCP Drivers (English)

Also, I added 0.1uF capacitor in between EN and GND on breadboard.

Then, I tried LED blink test. ( “Blink_ESP32.ino” link to the file is shown below)

Barduino2.0 class kit, soldering and functionality check

I confirmed the functionalities according to the tutorial below.

Barduino (fablab Kamakura-site)

( Barduino 2.0 (GitLab) )

1) soldering

Barduino-tools-setting

2) hello.ESP32-WROOM.echo(arduino) ( “hello.ESP32-WROOM.echo.ino” )

echo

3) LED Blink ( “Blink_ESP32.ino” file download link is shown below)

In addition to the above, I did ,,,

(a) install “pyserial” , because I found an error message “Error: No module named ‘serial’ ” from Terminal on MacBook.

pip3 install pyserial

(b) use the external power source ( 5V regulator + (1.5V battery X 6) ) instead of Mac USB while wifi communication from ESP32, because I got a message “Brownout detector was triggered” which means “not enough power provided by the computer USB port”, etc.

ref. 8. Error: “Brownout detector was triggered”