index

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Learning Objectives

• development Board and The sensor Connecting The method I understand .
• sensor of the class standard The model I understand .
• By type sensor class directly Let's make it .

​

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detail outline

• sensor standard Utilization and Information expression
• Each connection By method Features and avatar method

​

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9.1 Sensor standard In a way �How to use

The sensor standard In a way How to use

9.1 Sensor standard In a way How to use

Diversity of sensor connections

Sensors connected to the development board have different data types and communication methods.

Representing sensors in a standardized way (e.g., JSON format) facilitates server transmission and program integration.

Standard data representation examples

In the example, the values of the DHT22, DS18B20, and BH1750 sensors are organized into a dictionary.

Consolidate the measurements and units (e.g., temperature, humidity, and light) of each sensor into a single dictionary.

Detailed description

The sensor class reads the data and returns it with a "TempUnit" and key-value pairs for each sensor.

This standardized representation allows multiple sensor data to be processed at once or transmitted via protocols such as MQTT.

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1. Development On the board Pin and The sensor Connecting method

9.1 Sensor standard In a way How to use

Type 1: Direct pin manipulation

A way to directly manipulate the digital or analog information of a pin

Type 2: Library Utilization

How to utilize a sensor connected to a pin using a specific library

Types 3-6: Utilizing communication functions

Using the communication functions built into the development board

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2. Sensor's information expression Standardize

9.1 Sensor standard In a way How to use

• Standardized In a way sensor Expressing values​
• The value expression is Dictionary Format Used​
• One In the dictionary several doggy of the sensor The value Integrated​
• Dictionary In the form of The data is in JSON format Change to MQTT server Sent

• JavaScript Object Notation Abbreviation
• Computing equipment Between Information exchange format
• Dictionary as a string It's okay to understand that it 's changed

​

• Messaging Queuing Telemetry Transport Abbreviation
• IoT For devices communication Protocol �( detailed in Chapter 10 )

​

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3. Program Piece By pattern Register Reuse

9.1 Sensor standard In a way How to use

• Standardized blocks of code for repeated use

• Define the part to be changed as {{name}}

• Make it once and use it repeatedly

• Pattern names must not be duplicated

• Expressed in YAML format

• Create a separate file for the pattern and copy it for use.

• Express the code to be converted by referencing the pattern

• Specify {{name}} etc. defined in the pattern

• The same pattern can be used multiple times

• Expressed in YAML format

• YAML stands for "YAML Ain't Markup Language"

• Data can be expressed structurally

• Provides a more readable and concise syntax than JSON

• Sub-items are indented

• Prefix repeating items with '-'

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3. Program Piece By pattern Register Reuse

9.1 Sensor standard In a way How to use

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3. Program Piece By pattern Register Reuse

9.1 Sensor standard In a way How to use

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3. Program Piece By pattern Register Reuse

9.1 Sensor standard In a way How to use

Even if the prompt deviates somewhat from YAML's syntax ,

AI understands the author's intention and delivers the right result. zoom .

prompt

File name: ai-example-pattern-register.md

• AI prompts for pattern registration written in YAML format. Interpret it Generates code patterns intended by the user

​

• This way Through Repeatedly Used cord The structure efficiently Can be managed .

​

​

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3. Program Piece By pattern Register Reuse

9.1 Sensor standard In a way How to use

Configuring YAML Prompts

Use YAML-formatted prompts when defining parts.

You can use the pre-made pattern file in the front for common use.

Only the pattern information specified in the prompt is used, and the rest is ignored.

Define part usage

Defines the use of components by starting with components:

Each part is specified in the format - key: value

The same pattern can be used multiple times (repeated use possible)

Structure and readability

Items marked with - can be placed alongside the parent key, and indentation is omitted to improve readability.

If the source code appears in the middle, start with components: to separate it.

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3. Program Piece By pattern Register Reuse

9.1 Sensor standard In a way How to use

prompt

Filename: ai-example-for-use-as-part.md

• AI interprets the component usage prompts written in YAML format . Code that applies the pattern Created​

​

• This way, predefined patterns can be adapted to various situations. Can be customized for use

Even if the prompt deviates somewhat from YAML's syntax ,

AI understands the author's intention and delivers the right result. zoom

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3. Program Piece By pattern Register Reuse

9.1 Sensor standard In a way How to use

from machine import Pin from run import Run import pinno as P run = Run() from blink import Blink led_1 = Blink(pin_instance=Pin(P.LED_1_IN, Pin.OUT), inverted=False) run.add(led_1.run) def led_toggle(): led_1.toggle() from timerrun import TimerRun timer_led = TimerRun(period=1 * 1000, callback=led_toggle) run.add(timer_led.run) def main(): while True: run.run() if __name__ == '__main__': main()

controls the LED generated using the pattern and component concepts. This is a program . I am implementing a function to blink an LED periodically using a timer .

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3. Program Piece By pattern Register Reuse

9.1 Sensor standard In a way How to use

1

Generate concise code

Generate excellent code by simply specifying component usage in YAML.

2

Understanding the intention

AI understands the author's intent through YAML syntax and patterns: and components: keys.

3

Clear program definition

The concept of 'pattern' and 'part' can simplify and clarify program definition.

4

Leveraging common patterns

Common patterns are registered in the 'ai-patterns.md' file, and the description of the pattern itself should be checked in that file.

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4. Sensor class For Template prompt

9.1 Sensor standard In a way How to use

Sensor class

This class is for using a specific sensor.

Returns the sensor values in a standardized JSON format .�

Sensor Class Template Prompt

A universal prompt for creating a class that reads the values from a sensor.

If you get an error when creating a specific sensor class, you will need to modify the prompt.

All sensor classes in this book are �Written with this prompt. �Example) DHT22, BH1750, DS18B20

prompt

Filename : ai-9-1-sensor-class-template.md

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9.2 [ Type 2] �Individual On the pin Connect

1~2. Individual pin connection method and circuit diagram

9.2 [ Type 2] Individual On the pin Connect

Concept and Features

• How to read sensor data by connecting directly to individual pins

• built-in) like DHT22 temperature and humidity sensor Often used in clothing modules

Circuit and configuration

• The sensor module consists of GND, VCC, and data pins �(requires a pull-up resistor of 4.7kΩ).

• For ESP32, it is usually 3.3V power Use �(but may require 5V depending on the sensor)

Detailed description

• Refer to the circuit diagram for the DHT22 shield or �Breadboard configuration

• In the class example, the dht.DHT22 object �It generates and measures sensor values, and includes an exception handling routine when an error occurs.

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3. DHT22Sensor class Making – Using Circuit

9.2 [ Type 2] Individual On the pin Connect

Circuit example

• DHT22 shield Octoboard's In the outer pin area Equipped

• C3 mini on breadboard With parts circuit composition

target

• DHT22 temperature and humidity The sensor How to use For class
• [AI prompt Sensor of [Practice 9-1] class Template Take advantage of it Create .

• Octoboard's external C3 mini and DHT22 shield in the pin area Even if you equip it No problem

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3. DHT22Sensor class Create - Prompts and cord

9.2 [ Type 2] Individual On the pin Connect

Generative To AI Coding

• AI prompt Exercise 9-2

• File name : ai-9-2-DHT22Sensor-class-create.md

AI Printed MicroPython cord

• Program 9-2

• File name : \lib\dht22sensor.py

Webpage

• https://iotmaker.kr/mpy-ai-9-2/

[ explanation ]

a class that reads temperature and humidity data in a standardized format using the DHT22 temperature and humidity sensor. Implemented​

- Created by generative AI using sensor class templates Code Im

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4. Parse class How to use

9.2 [ Type 2] Individual On the pin Connect

from parse import Parse data = {'DHT22': {'Temperature': 25.6, 'Humidity': 45}, 'TempUnit': 'C'} p = Parse(data) print(p.name) # 'DHT222' print(p.names) # ['DHT22'] print(p.key) # 'Humidity' print(p.keys) # ['Humidity','Temperatute'], ascending order print(p.value) # 45 print(p.values) # [45,25,6], p.keys order print(p.temp_unit) # 'C'

• Using the sensor class The received value is in JSON format data By property The Parse class that displays How to use
• way to access sensor data . Provided​

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4. Parse 클래스 사용법

9.2 [유형 2] 개별 핀에 연결하기

class Parse:

​

def __init__(self, data):

​

self.data = data

​

# 기본값

self.name = None

self.names = []

​

self.key = None

self.keys = []

​

self.value = None

self.values = []

​

self.temp_unit = None

​

# TempUnit 추출

if "TempUnit" in data:

self.temp_unit = data["TempUnit"]

​

# 센서 이름 찾기

for k in data:

​

if type(data[k]) == dict:

​

self.names.append(k)

​

self.names.sort()

# 첫 번째 센서...

​

# 첫 번째 센서

if len(self.names):

​

self.name = self.names[0]

​

sensor_data = data[self.name]

​

# key 목록

self.keys = list(sensor_data.keys())

self.keys.sort()

​

# 첫 번째 key

if len(self.keys):

self.key = self.keys[0]

​

# values 생성

for k in self.keys:

self.values.append(sensor_data[k])

​

# 첫 번째 value

if len(self.values):

self.value = self.values[0]

​

def get(self, key, default=None):

​

if self.name is None:

return default

​

sensor_data = self.data[self.name]

​

if key in sensor_data:

return sensor_data[key]

​

return default

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4. Parse class How to use

9.2 [ Type 2] Individual On the pin Connect

names

Sensor name List

name

Same as names[0]

Typically used to refer to a single sensor or the very first sensor.

keys

name of sensor data List

key

Same as keys[0]

For DHT22, ' Humidity' is sorted in ascending order. being

values

The values corresponding to the keys List

value

Same as values[0]

temp_unit

Indicates the temperature unit string

Usually 'C', 'F' or blank (' ') if there is no value . Set​

OneWire related properties

ow_id, ow_ids, ow_key, ow_keys, ow_value, ow_values

To access OneWire sensor data: properties​

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9.3 [ Type 3] �On the I2C bus Connect

1. I2C bus connection method

9.3 [ Type 3] On the I2C bus Connect

Connect one master and multiple slaves (up to 126) with just two lines (SCL, SDA)

Sensor examples: BH1750 (light sensor), OLED display

I2C communication is an efficient communication method that can connect multiple devices using only two lines (SCL: clock, SDA: data). method

One master device (typically a microcontroller) can communicate with multiple slave devices (sensors, displays, etc. )

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1. I2C bus connection method

9.3 [ Type 3] On the I2C bus Connect

Check for address conflicts

Ensure that address conflicts between components within the same I2C bus are avoided.

2

Check your PIN number

Check pin numbers when setting up the I2C bus on the ESP32 S3 mini board

Connection configuration

Connect to appropriate pins, such as SCL→GPIO36, SDA→GPIO35

When using the I2C bus, all connected devices must have a unique address. box

Also, you need to check the I2C pin number of the development board and connect it correctly. box

On the ESP32 S3 mini board, the SCL and SDA pins are assigned to specific GPIO pins. There is

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2. BH1750 and OLED circuit diagram

9.3 [ Type 3] On the I2C bus Connect

I2C bus sharing

Two parts share a single I2C bus.

I2C address

The default I2C addresses for each component are 0x23(35) and 0x3c(60), respectively.

Connection method

Both devices are connected via the SCL and SDA lines. �It connects to the microcontroller .

use I2C communication. device

Since the two devices have different I2C addresses, they can be connected together on a single I2C bus .

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3. On OLED Alphanumeric characters and korean Show

9.3 [ Type 3] On the I2C bus Connect

• OLED display with a resolution of 64x48

• Specifies the coordinates of the upper left corner of the text

• Uses SSD1306 chipset

• The default I2C address is 0x23(35)

• A low-cost, written module for displaying Korean characters

• Can be printed by enlarging the size by 2x in all directions

• Provides a function to efficiently display Korean fonts.

• Readable Korean text even on small OLED screens

screen despite their small size. Provided​

The specially designed hangul.py module allows you to display Korean characters neatly, allowing you to visually present a variety of information .

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3. On OLED Alphanumeric characters and korean Display – Used Circuit

9.3 [ Type 3] On the I2C bus Connect

Circuit example

• OLED shield Octoboard's In the outer pin area Equip it .

• C3 mini on breadboard With OLED The circuit Configure .

target

• I2C communication In a way On the connected OLED shield Hangul It displays .

• Octoboard's external C3 mini and OLED shield in the pin area Even if you equip it It will work .

The OLED display is connected to the microcontroller via I2C communication.

This circuit allows you to display text and simple graphics . �It can be used for various purposes such as sensor data visualization and status display.

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3. On OLED Alphanumeric characters and korean Show

9.3 [ Type 3] On the I2C bus Connect

• Program 9-3

• File name : 9_3_oled.py

This code is for OLED display Hangul and Alphanumeric characters Displaying Function Implemented​

SSD1306 driver and hangul.py module By using various Text Can be displayed

- Korean and alphanumeric characters together on the OLED screen Displayed​

- Readable information even on small screens

- OLED displays provide a clear screen despite their small size, making them very useful for visually displaying information in IoT projects.

​

- The Korean display function can provide more diverse information to users .

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4. BH1750Sensor class Making – Using Circuit

9.3 [ Type 3] On the I2C bus Connect

Circuit example

• OLED shield Octoboard's In the outer pin area Equip it .

• C3 mini on breadboard With OLED The circuit Configure .

target

• I2C communication In a way Connected BH1750 ambient light ( illuminance ) sensor How to use For Class ' Sensor class Template' Take advantage of it Create .

• Octoboard's external C3 mini and OLED shield in the pin area Even if you equip it It will work .

BH1750 illumination The sensor uses I2C communication Through circumference of light Brightness Measurable​​ It's a sensor .

This sensor By using circumference of the environment In brightness according to various Action Performing The project It can be implemented .

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4. BH1750Sensor class Create - Prompts and cord

9.3 [ Type 3] On the I2C bus Connect

Generative To AI Coding

• AI prompt Exercise 9-4

• File name : ai-9-3-BH1750Sensor-class-create.md

AI Printed MicroPython cord

• Program 9-4

• File name : \lib\bh1750sensor.py

Webpage

• https://iotmaker.kr/mpy-ai-9-3/

[ explanation ]

- This code creates a class that measures the brightness of the ambient light using the BH1750 light sensor and returns the data in a standardized format. Implemented​

- Created by generative AI using sensor class templates cord

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5. BH1750's illuminance The value On OLED Display – Used Circuit

9.3 [ Type 3] On the I2C bus Connect

Circuit example

• S3 mini development Board and Ambient light Shield , and OLED shield �Octoboard's In the outer pin area Equip it

• C3 mini on breadboard With parts The circuit It consists of

target

• Ambient light periodically Read it Content On OLED Print it out .

This circuit displays the light intensity values measured by the BH1750 light sensor in real time on an OLED display. �Since both devices use I2C communication, they can be connected to the same I2C bus for efficient configuration.

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5. BH1750's illuminance The value On OLED Display - Prompt and cord

9.3 [ Type 3] On the I2C bus Connect

Generative To AI Coding

• AI prompt Exercise 9-4

• File name : ai-9-4-bh1750-oled.md

AI Printed MicroPython cord

• Program 9-5

• File name : 9_5_bh1750_oled.py

Webpage

• https://iotmaker.kr/mpy-ai-9-4/

• Module name : lib\ssd1306.py

[ explanation ]

• This code periodically reads the light brightness values measured by the BH1750 light sensor and displays them on the OLED display. Show​
• Useful for environmental monitoring projects as it allows visual confirmation of changing illuminance values in real time.

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9.4 [ Type 4] �On the I2C bus Connect

1. OneWire bus connection method

9.4 [ Type 4] On the I2C bus Connect

One data By line Multiple DS18B20 temperatures The sensor Multidrop In a way connection

Each DS18B20 has its own unique ID Because I have several The sensor individually division possible

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2. DS18B20 circuit diagram

9.4 [ Type 4] On the I2C bus Connect

Circuit diagram explanation

​

​

The DS18B20 sensor requires a 4.7kΩ �pull-up resistor on the data pin .

Connection method

connection of VCC, GND, and data pins method

The data pin is connected to VCC through a pull-up resistor.

Multi-drop configuration

Multiple DS18B20 sensors can be connected in parallel

Each sensor is identified by a unique ID . access

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3. DS18B20Sensor class Create - Prompts and cord

9.4 [ Type 4] On the I2C bus Connect

Generative To AI Coding

• AI prompt Exercise 9-5

• File name : ai-9-5-DS18B20Sensor-class-create.md

AI Printed MicroPython cord

• Program 9-6

• File name : \lib\ds18b20sensor.py

Webpage

• https://iotmaker.kr/mpy-ai-9-5/

[ explanation ]

- This code is for DS18B20 temperature The sensor By using Temperature Measure and Standardized In the format data Returning class Implemented​

- OneWire Communication Through several The sensor Identify and individually Temperature Can read​

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9.5 [ Type 5] �On the SPI bus Connect

1. SPI bus connection method

9.5 [ Type 5] On the SPI bus Connect

Pin configuration

SPI consists of three common pins, SCK, MOSI, and MISO, and one SS (slave select) pin added for each slave. Composed​

For example, when connecting one sensor, four �pins are required. Need​

Communication method

selects a specific slave by individual pin. Communication box

Faster communication speed than I2C due to dedicated data line

Application areas

method for connecting microcontroller and flash memory Used​

often adopt SPI instead of I2C for faster response speed .

SPI on ESP32

provides two SPI buses that can be used independently by the user .

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2. SD card and RTC shield Circuit diagram

9.5 [ Type 5] On the SPI bus Connect

SPI vs. I2C

• The SPI method is better than the I2C method . By far speed

• file Input/output , high resolution Fast display etc. Transmission necessary case use

data Logger program

• In JSON format on SD card Information Recording data Logger avatar

• Using DHT22 Temperature and humidity Information acquisition

hardware composition

• Two shields together Use it Optimal data Logger Device produce possible

The SD card uses SPI communication Through fast data Save It is possible , and the RTC (Real-Time Clock) uses I2C communication. Through accurate hour Information We provide these two modules . together If you use it hour Information and together sensor Data to SD card Saving data logger It can be implemented .

• RTC function hour Information acquisition

• Two shields Combined One With a shield To be implemented capital There is

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3. UseSDCard class Create - Prompts and cord

9.5 [ Type 5] On the SPI bus Connect

Generative To AI Coding

• AI prompt Exercise 9-6

• File name : ai-9-6-UseSDCard-Class-Create.md

AI Printed MicroPython cord

• Program 9-7

• File name : \lib\usesdcard.py

Webpage

• https://iotmaker.kr/mpy-ai-9-6/

[ explanation ]

• This code is for SD card and By communicating file Read inscribed Function Provided by class Implemented​
• SPI communication via SD card Access and data Save or Can be called up
• data Logging or setting Various storage etc. For the purpose You can utilize it .

​

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4. Temperature and humidity Information Time and Together on the SD card Recording – Usage Circuit

9.5 [ Type 5] On the SPI bus Connect

Circuit example

• S3 mini development Board and SD shield , RTC shield and �DHT22 shield Octoboard's In the inner pin area Equip it .

• C3 mini on breadboard With parts The circuit Configure .

target

• DHT22 temperature and humidity Information Time and Together on the SD card Record it .

This circuit uses a DHT22 sensor measured Temperature and humidity Data from RTC module Provided by accurate hour Information and Together on the SD card Save it .

This Through Hourly environment data Record it Analyzable​​ data logger It can be implemented .

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4. Temperature and humidity Information Time and Together on the SD card Record - Prompt and cord

9.5 [ Type 5] On the SPI bus Connect

Generative To AI Coding

• AI prompt Exercise 9-7

• File name : ai-9-7-UseSDCard-rtc-dht22.md

AI Printed MicroPython cord

• Program 9-8

• File name : 9_8_usesdcard_rtc_dht22.py

Webpage

• https://iotmaker.kr/mpy-ai-9-7/

• Module name : lib\sdcard.py

[ explanation ]

This code is for DHT22 sensor measured Temperature and humidity Data from RTC module Provided by hour Information and Together on the SD card Save​

In RTC today Time Setting up The procedure is required and once set Time is battery Lifespan I'll do it Until Maintained​

accurate Time Need Every time today Time again Setting up That 's good

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9.6 [ Type 6] �Connecting via UART

1. Connecting UART pins method

9.6 [ Type 6] Connecting via UART

Communication method

UART is an asynchronous serial communication method that uses TX (transmit) and RX (receive) data lines for 1:1 communication without a separate synchronization signal.

Connection structure

The TX pin of one device must be connected to the RX pin of the other device, and the data transmission speed is agreed upon in advance by both parties.

No master/slave distinction

Either device can initiate communication first, so they communicate on an equal footing.

Configuring UART on ESP32

ESP32 has three UARTs: UART0, UART1, and UART2.

UART0 is connected to the built-in USB device and is used as a MicroPython REPL, so it is better to avoid it when connecting other devices.

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2. UART's data form

9.6 [ Type 6] Connecting via UART

Differences in string representation

• String representations on MicroPython and UART devices may differ.

ASCII code

• Expresses 128 characters (alphabet, numbers, special symbols, control characters) using 7 bits out of 1 byte (8 bits)

Unicode

• Basically, it represents characters all over the world in 2 bytes.

• Python and MicroPython use Unicode as their internal character set.

UTF-8 encoding

• Use ASCII-based encoding to reduce data transfer volume during external communication.

• ASCII characters are expressed in 1 byte, and Korean characters are expressed in 3 bytes, so they can be distinguished.

- In UART communication string data byte By unit Transmitting and receiving box

• MicroPython is Internally Unicode But use external communication The poem uses UTF-8 encoding. Through byte In the format Convert to Sent​
• Received byte The data is again Decode it as a string Need to convert

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3. UART commands

9.6 [ Type 6] Connecting via UART

UART initialization

UART(id, baudrate, tx, rx, timeout)

• id: UART number to use (0, 1, 2 for ESP32)

• baudrate: The transmission speed (e.g., 9600 or 115200)

• tx / rx: Transmit/receive pins (GPIO, multiplexable)

• timeout: Read wait time (in milliseconds)

• In ESP32, UART0 is reserved for REPL, and UART1 and UART2 are used for communication.

UART reading

• UART.any(): Checks if there is data in the receive buffer, and if so, returns the number of bytes.

• UART.read(size): Reads data of the specified size, or reads all data if size is not specified.

• UART.readline(): Reads data up to the newline character (\n) and processes it line by line.

Write UART

• UART.write(data): Send data (data is in str or bytes format, str is internally converted to bytes)

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4~5. UART1 and UART2 send information Give and Take – Usage Circuit

9.6 [ Type 6] Connecting via UART

Circuit example

• pins of UART1 and UART2 Mutual Connect

target

• ser on UART1 Number inclusive Dictionary Transmission

• UART2 does this Schedule after receiving hour Waiting , �ser Number Increase Transmit again to UART1

• UART1 receives the same The procedure Repeat

This circuit Interconnect UART1 and UART2 within one ESP32 Connect Two-way Communication Implements . �Each UART has data Sending Receiving Role alternately and perform this Through two devices liver communication The protocol You can test it .

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4~5. UART1 and UART2 send information Give and Take - Prompts and cord

9.6 [ Type 6] Connecting via UART

Generative To AI Coding

• AI prompt Exercise 9-8

• File name : ai-9-8-uart-ping-pong.md

AI Printed MicroPython cord

• Program 9-10

• File name : 9_10_uart_ping_pong.py

Webpage

• https://iotmaker.kr/mpy-ai-9-8/

[ explanation ]

communication to exchange data between UART1 and UART2. Implemented​

• one side transmits data containing a serial number, the other side receives it and increments the serial number. �The process of retransmitting Repeat​
• this , you can understand the basic principles of UART communication and JSON data exchange method .

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Practice Problems (1/2)

1

With RTC OLED Used clock program

These practice problems are in this chapter. learned various With sensors communication The method By utilizing Real IoT The project Implementing ability Test it .

RTC, OLED, DHT22 sensor Back In combination service Application Try making it .

• Set the date and time by entering it in the REPL.

• Displays date, day, and time on OLED.

• Implement a function to enter the date and time using two buttons and a potentiometer.

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Practice Problems (2/2)

2

With DHT22 sensor OLED Used Temperature and humidity Monitoring

• Temperature and humidity On OLED Please indicate .

• Dividing the temperature into three parts, the letters ' cold , normal , hot ' On OLED Please indicate .

• schedule Than temperature When it gets higher, it goes on the OLED screen. warning message Show and The buzzer turns ON/ OFF every 0.5 seconds. Keep going do .

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Q&A

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