LoPy: A Complete Overview

Introduction to LoPy

LoPy is a powerful IoT development platform that combines the ease of use of Python programming with the versatility and efficiency of the ESP32 microcontroller. Developed by PyCom, LoPy is designed to simplify the process of creating IoT applications by providing a comprehensive set of tools and features that enable developers to quickly prototype and deploy their projects.

Key Features of LoPy

Feature	Description
Micropython	LoPy supports Micropython, a lightweight and efficient implementation of Python 3 optimized for microcontrollers.
ESP32 Microcontroller	LoPy is powered by the ESP32 microcontroller, which offers dual-core processing, Wi-Fi, Bluetooth, and various peripherals.
Multiple Network Protocols	LoPy supports a wide range of network protocols, including Wi-Fi, Bluetooth, LoRa, and Sigfox.
Low Power Consumption	LoPy is designed for low power consumption, making it suitable for battery-powered applications.
Expandable with Shields	LoPy can be expanded with various shields, such as the PyTrack, PySense, and PyScan, to add additional functionality.

Request PCB Manufacturing & Assembly Quote Now

Hardware Specifications

ESP32 Microcontroller

At the heart of LoPy is the ESP32 microcontroller, which provides the following features:

Dual-core Xtensa LX6 microprocessor, running at 240 MHz
520 KB SRAM
4 MB flash memory
Wi-Fi (802.11 b/g/n)
Bluetooth Classic and Bluetooth Low Energy (BLE)
Multiple peripherals (I2C, SPI, UART, ADC, DAC, PWM, etc.)

LoPy Pin Layout

LoPy has a compact form factor with a pin layout that includes:

24 GPIO pins
2 UART interfaces
2 SPI interfaces
2 I2C interfaces
3 ADC channels
2 DAC channels
8 PWM channels

Power Management

LoPy has a built-in power management system that enables low power consumption and long battery life. It supports the following power modes:

Power Mode	Description
Active Mode	The microcontroller is fully operational, and all peripherals are available.
Sleep Mode	The microcontroller enters a low-power state, while retaining RAM contents and allowing the RTC and certain peripherals to operate.
Deep Sleep Mode	The microcontroller enters an ultra-low-power state, where RAM contents are lost, and only the RTC and specific GPIO pins can wake the device.

Software Development with LoPy

Micropython

LoPy supports Micropython, a lean and efficient implementation of Python 3 designed for microcontrollers. Micropython provides a familiar Python syntax and a subset of the Python standard library, making it easy for developers with Python experience to get started with LoPy.

Some key features of Micropython on LoPy include:

Support for Python 3.4 syntax
Access to LoPy-specific libraries for networking, sensors, and other peripherals
Interactive REPL (Read-Eval-Print Loop) for quick testing and debugging
Ability to run scripts from the built-in flash memory or an external SD card

Pymakr IDE

To simplify the development process, PyCom provides the Pymakr IDE, a free and cross-platform integrated development environment for LoPy and other PyCom devices. Pymakr offers the following features:

Syntax highlighting and auto-completion for Micropython
Built-in terminal for REPL access and debugging
Support for uploading and running scripts on LoPy
Integration with version control systems like Git
Available as a standalone application or a plugin for Visual Studio Code and Atom

LoPy Libraries

LoPy comes with a set of built-in libraries that provide access to various features and peripherals of the device. Some of the key libraries include:

Library	Description
`machine`	Provides access to the hardware peripherals, such as GPIO, I2C, SPI, and UART.
`network`	Enables the use of Wi-Fi, Bluetooth, and other network protocols.
`pycom`	Offers LoPy-specific functions and constants.
`utime`	Provides time-related functions, such as delays and timers.
`uos`	Allows access to the file system and basic OS functions.

Networking with LoPy

One of the key strengths of LoPy is its support for multiple network protocols, which enables developers to create IoT applications that can communicate with a wide range of devices and services.

Wi-Fi

LoPy supports 802.11 b/g/n Wi-Fi, allowing it to connect to or create Wi-Fi networks. The network library provides classes and methods for configuring and managing Wi-Fi connections, such as:

Scanning for available networks
Connecting to a Wi-Fi network
Creating a Wi-Fi access point
Retrieving network information (IP address, MAC address, etc.)

Example code for connecting to a Wi-Fi network:

from network import WLAN

wlan = WLAN(mode=WLAN.STA)
wlan.connect('your_ssid', auth=(WLAN.WPA2, 'your_password'))

while not wlan.isconnected():
    pass

print('Connected to Wi-Fi:', wlan.ifconfig())

Bluetooth

LoPy supports both Bluetooth Classic and Bluetooth Low Energy (BLE). The bluetooth library allows developers to use LoPy as a Bluetooth peripheral or central device, enabling communication with other Bluetooth devices, such as smartphones, tablets, or sensors.

Example code for creating a Bluetooth Low Energy peripheral:

from network import Bluetooth

bluetooth = Bluetooth()
bluetooth.set_advertisement(name='My LoPy', service_uuid=b'1234567890123456')

def conn_cb (bt_o):
    events = bt_o.events()
    if  events & Bluetooth.CLIENT_CONNECTED:
        print("Client connected")
    elif events & Bluetooth.CLIENT_DISCONNECTED:
        print("Client disconnected")

bluetooth.callback(trigger=Bluetooth.CLIENT_CONNECTED | Bluetooth.CLIENT_DISCONNECTED, handler=conn_cb)

bluetooth.advertise(True)

LoRa

LoRa is a long-range, low-power wireless communication protocol designed for IoT applications. LoPy supports LoRa through the LoRa class in the network library, enabling developers to create LoRa networks or connect to existing ones, such as The Things Network (TTN).

Example code for sending data via LoRa:

from network import LoRa
import socket

lora = LoRa(mode=LoRa.LORA, frequency=868000000)
s = socket.socket(socket.AF_LORA, socket.SOCK_RAW)
s.setblocking(True)

s.send('Hello, LoRa!')
s.close()

Sigfox

Sigfox is another low-power, long-range network protocol supported by LoPy. The Sigfox class in the network library allows developers to send and receive messages using the Sigfox network.

Example code for sending data via Sigfox:

from network import Sigfox
import socket

sigfox = Sigfox(mode=Sigfox.SIGFOX, rcz=Sigfox.RCZ1)

s = socket.socket(socket.AF_SIGFOX, socket.SOCK_RAW)
s.setblocking(True)

s.send('Hello, Sigfox!')
s.close()

Shields and Expansions

LoPy can be extended with various shields and expansions that add additional functionality to the device. Some popular shields include:

PyTrack

PyTrack is a shield that adds GPS and accelerometer capabilities to LoPy. It features a GPS receiver and a 3-axis accelerometer, enabling developers to create location-aware and motion-sensing applications.

Feature	Description
GPS	u-blox MAX-M8Q GPS receiver with integrated antenna
Accelerometer	ST LIS2HH12 3-axis accelerometer
Backup Battery	CR1220 coin cell battery for RTC backup and GPS RAM retention

PySense

PySense is a shield that provides a range of Environmental Sensors, including temperature, humidity, pressure, light, and acceleration. It is designed for applications that require monitoring of ambient conditions, such as weather stations or smart home devices.

Feature	Description
Temperature and Humidity	SI7006-A20 sensor
Pressure	MPL3115A2 sensor
Light	LTR-329ALS-01 sensor
Acceleration	ST LIS2HH12 3-axis accelerometer

PyScan

PyScan is a shield that adds RFID and NFC capabilities to LoPy. It features an MFRC630 RFID/NFC reader, allowing developers to create applications that can read and write to RFID tags and NFC devices.

Feature	Description
RFID/NFC	NXP MFRC630 reader
Frequency	13.56 MHz
Standards	ISO/IEC 14443 A/B, ISO/IEC 15693, ISO/IEC 18000-3, NFC Forum Type 1-5

Real-World Applications

LoPy’s versatility and support for multiple network protocols make it suitable for a wide range of IoT applications. Some examples include:

Smart Agriculture

Monitoring soil moisture, temperature, and humidity
Controlling irrigation systems based on sensor data
Tracking livestock with GPS and LoRa

Industrial Automation

Monitoring machine performance and energy consumption
Predictive maintenance based on sensor data
Remote control of industrial equipment

Smart Cities

Environmental monitoring (air quality, noise levels, etc.)
Smart parking systems with RFID/NFC
Waste management with fill-level sensors and LoRa

Home Automation

Smart thermostats and HVAC control
Lighting control based on ambient light levels
Security systems with motion detection and Bluetooth connectivity

Getting Started with LoPy

To start developing with LoPy, follow these steps:

Purchase a LoPy device and any necessary shields or expansions.
Install the Pymakr IDE on your computer.
Connect your LoPy to your computer via USB.
Open Pymakr and create a new project.
Write your Micropython code using the LoPy libraries and features.
Upload and run your code on the LoPy device.

For more detailed tutorials and examples, refer to the official PyCom documentation and community resources.

FAQ

What is the difference between LoPy and other PyCom devices?

LoPy is one of several devices offered by PyCom, each with different features and capabilities. Other devices include WiPy (focused on Wi-Fi), SiPy (focused on Sigfox), and GPy (focused on cellular connectivity). LoPy stands out for its support of multiple network protocols, including Wi-Fi, Bluetooth, LoRa, and Sigfox.

Can I use LoPy without any shields or expansions?

Yes, LoPy can be used as a standalone device without any additional shields or expansions. However, shields like PyTrack, PySense, and PyScan can greatly extend the capabilities of LoPy and make it easier to develop certain types of applications.

Is LoPy suitable for beginners?

While some prior experience with Python and electronics can be helpful, LoPy is designed to be beginner-friendly. The use of Micropython and the Pymakr IDE makes it easier for developers to get started with LoPy compared to other microcontroller platforms that require more low-level programming.

What is the maximum range of LoRa and Sigfox on LoPy?

The maximum range of LoRa and Sigfox on LoPy depends on various factors, such as the environment, antenna design, and transmission power. In ideal conditions, LoRa can achieve a range of up to 10 km, while Sigfox can reach up to 50 km. However, in urban areas or environments with obstacles, the range may be significantly lower.

Can I use LoPy for commercial projects?

Yes, LoPy can be used for both personal and commercial projects. PyCom offers a range of services and support options for commercial customers, including custom firmware development, hardware design, and certification assistance.