jobs.html

member

Basics: Project 072n ESP32 Development board - NTP client (date and time)

of Acoptex.com in ESP8266 ESP-32

Basics: Project 072n

Project name: ESP32 Development board - NTP client (date and time)

Tags: ESP32 Dev Module, ESP32 development board, ESP32 Development board with WiFi and Bluetooth, ESP32-DevKitC V4 development board, ESP-WROOM-32 module with ESP32‑D0WDQ6 chip, Espressif Systems, ESP32-based development board, ESP32 modules, ESP32-WROOM-32, ESP32-WROOM-32U, ESP32-WROOM-32D, ESP32-SOLO-1, USB-UART bridge, IOT, ESP-WROOM-32 Dev Module, ESP32 DEVKITV1, Installing the ESP32 Board in Arduino IDE, Uploading sketch, NTP client, date and time

Attachments: sketch1, library1

In this project, you need these parts :

1. ESP32 development board with WiFi and Bluetooth and USB A / micro USB B cable 1 pc

2.Arduino IDE ( you can download it from here )

General

We will learn how to get date and time with the ESP32 development board. Date and time are very useful in data logging for sensor readings timestamp. If your ESP32 development board has access to the Internet, you can get date and time using Network Time Protocol (NTP) – no additional hardware required.

There are a lot of different development boards made. You can find more information about them here.

Understanding the ESP32 Development board with WiFi and Bluetooth

We will discuss here an Espressif Systems products. Our development board is using ESP-WROOM-32 module from Espressif Systems.

Espressif offers a wide range of fully-certified Wi-Fi & BT modules powered by their own advanced SoCs.

1. Dual-core Modules with Wi-Fi & Dual-mode Bluetooth

Features

Two independently-controlled CPU cores with adjustable clock frequency, ranging from 80 MHz to 240 MHz
+19.5 dBm output at the antenna ensures a good physical range
Classic Bluetooth for legacy connections, also supporting L2CAP, SDP, GAP, SMP, AVDTP, AVCTP, A2DP (SNK) and AVRCP (CT)
Support for Bluetooth Low Energy (BLE) profiles including L2CAP, GAP, GATT, SMP, and GATT-based profiles like BluFi, SPP-like, etc
Bluetooth Low Energy (BLE) connects to smart phones, broadcasting low-energy beacons for easy detection
Sleep current is less than 5 μA, making it suitable for battery-powered and wearable-electronics applications
Integrates 4 MB flash
Peripherals include capacitive touch sensors, Hall sensor, low-noise sense amplifiers, SD card interface, Ethernet, high-speed SPI, UART, I2S and I2C
Fully certified with integrated antenna and software stacks

2. Single-core Modules with Wi-Fi & Dual-mode Bluetooth

Features

High-performance 160 MHz single-core CPU
+19.5 dBm output at the antenna ensures a good physical range
Classic Bluetooth for legacy connections, also supporting L2CAP, SDP, GAP, SMP, AVDTP, AVCTP, A2DP (SNK) and AVRCP (CT)
Support for Bluetooth Low Energy (BLE) profiles including L2CAP, GAP, GATT, SMP, and GATT-based profiles like BluFi, SPP-like, etc
Bluetooth Low Energy (BLE) connects to smart phones, broadcasting low-energy beacons for easy detection
Sleep current is less than 5 μA, making it suitable for battery-powered and wearable-electronics applications
Peripherals include capacitive touch sensors, Hall sensor, low-noise sense amplifiers, SD card interface, Ethernet, high-speed SPI, UART, I2S and I2C
Fully certified with integrated antenna and software stacks

3. Single-core Modules with 802.11b/g/n 2.4 GHz Wi-Fi

Features

High-performance 160 MHz single-core CPU
+19.5 dBm output at the antenna ensures a good physical range
Sleep current is less than 20 μA, making it suitable for battery-powered and wearable-electronics applications
Peripherals include UART, GPIO, I2C, I2S, SDIO, PWM, ADC and SPI
Fully certified with integrated antenna and software stacks

There are different development Boards made by Espressif Systems and other manufacturers. We will publish some information about Espressif Systems boards but you can also find out more information about other development boards here.

1. 2.4 GHz Wi-Fi & BT/BLE Development Boards

Features

PC connectivity: USB
Power supply options: USB (by default), or 5V/GND header pins, or 3V3/GND header pins
SDK: ESP-IDF source code and example applications

2. 2.4 GHz Wi-Fi Development Boards

Features

PC connectivity: USB
SDK: ESP8266 SDK source code and example applications

3. 2.4 GHz Wi-Fi + BT/BLE + Sensor Development Boards

Features

PC connectivity: USB
SDK: ESP-IOT-SOLUTION source code and example applications

You can find more information (datasheets, schematics, pins descriptions, functional desgn descriptions) about each board by pressing Getting started link close to each board here.

ESP32 chip

ESP32 is a series of low cost, low power system on a chip microcontrollers with integrated Wi-Fi and dual-mode Bluetooth. The ESP32 series employs a Tensilica Xtensa LX6 microprocessor in both dual-core and single-core variations and includes in-built antenna switches, RF balun, power amplifier, low-noise receive amplifier, filters, and power management modules. ESP32 is created and developed by Espressif Systems, a Shanghai-based Chinese company, and is manufactured by TSMC using their 40 nm process. It is a successor to the ESP8266 microcontroller.

ESP32 can perform as a complete standalone system or as a slave device to a host MCU, reducing communication stack overhead on the main application processor. ESP32 can interface with other systems to provide Wi-Fi and Bluetooth functionality through its SPI / SDIO or I2C / UART interfaces.

ESP32 is highly-integrated with in-built antenna switches, RF balun, power amplifier, low-noise receive amplifier, filters, and power management modules. ESP32 adds priceless functionality and versatility to your applications with minimal Printed Circuit Board (PCB) requirements.

ESP32 is capable of functioning reliably in industrial environments, with an operating temperature ranging from –40°C to +125°C. Powered by advanced calibration circuitries, ESP32 can dynamically remove external circuit imperfections and adapt to changes in external conditions.

Engineered for mobile devices, wearable electronics and IoT applications, ESP32 achieves ultra-low power consumption with a combination of several types of proprietary software. ESP32 also includes state-of-the-art features, such as fine-grained clock gating, various power modes and dynamic power scaling.

Functional Block Diagram:

Features of the ESP32 include the following:

Processors:

CPU: Xtensa dual-core (or single-core) 32-bit LX6 microprocessor, operating at 160 or 240 MHz and performing at up to 600 DMIPS
Ultra low power (ULP) co-processor
Memory: 520 KiB SRAM

Wireless connectivity:

Wi-Fi: 802.11 b/g/n
Bluetooth: v4.2 BR/EDR and BLE

Peripheral interfaces:

12-bit SAR ADC up to 18 channels
2 × 8-bit DACs
10 × touch sensors (capacitive sensing GPIOs)
Temperature sensor
4 × SPI
2 × I²S interfaces
2 × I²C interfaces
3 × UART
SD/SDIO/CE-ATA/MMC/eMMC host controller
SDIO/SPI slave controller
Ethernet MAC interface with dedicated DMA and IEEE 1588 Precision Time Protocol support
CAN bus 2.0
Infrared remote controller (TX/RX, up to 8 channels)
Motor PWM
LED PWM (up to 16 channels)
Hall effect sensor
Ultra low power analog pre-amplifier

Security:

IEEE 802.11 standard security features all supported, including WFA, WPA/WPA2 and WAPI
Secure boot
Flash encryption
1024-bit OTP, up to 768-bit for customers
Cryptographic hardware acceleration: AES, SHA-2, RSA, elliptic curve cryptography (ECC), random number generator (RNG)

Power management:

Internal low-dropout regulator
Individual power domain for RTC
5uA deep sleep current
Wake up from GPIO interrupt, timer, ADC measurements, capacitive touch sensor interrupt

You can find ESP32 chip datasheet here, hardware design here, technical reference manual here.

Signals and connections of the ESP32 Development board with WiFi and Bluetooth

You can find more information (datasheets, schematics, pins descriptions, functional desgn descriptions) about each board (made by Espresiff Systems) by pressing Getting started link close to each board here.

Let's check our development board - ESP32 DEVKITV1 with ESP-WROOM-32 module from Espressif Systems:

Pinout diagram for the ESP Wroom 32 breakout:

ESP32-WROOM-32 - ESP32-WROOM-32 module soldered to the development board. Optionally ESP32-WROOM-32D, ESP32-WROOM-32U or ESP32-SOLO-1 module may be soldered instead of the ESP32-WROOM-32.

USB-UART Bridge - A single chip USB-UART bridge provides up to 3 Mbps transfers rates.

BOOT button - Download button: holding down the Boot button and pressing the EN button initiates the firmware download mode. Then user can download firmware through the serial port.

EN button - Reset button: pressing this button resets the system.

Micro USB Port - USB interface. It functions as the power supply for the board and the communication interface between PC and the ESP module.

TX0, TX2 - transmit pin. GPIO pin

RX0, RX2 - receive pin. GPIO pin

3V3 (or 3V or 3.3V) - power supply pin (3-3.6V).

GND - ground pin.

EN - Chip enable. Keep it on high (3.3V) for normal operation.

Vin - External power supply 5VDC.

Wiring

Step by Step instruction

The ESP32 is currently being integrated with the Arduino IDE like it was done for the ESP8266. There’s an add-on for the Arduino IDE that allows you to program the ESP32 using the Arduino IDE and its programming language.

Download and install the latest Arduino IDE Windows Installer from arduino.cc
Download and install Git and Git GUI from git-scm.com
Search for Git GUI, right-click the icon and select “Run as administrator“
Select the Clone Existing Repository option.
Select source and destination. Source Location: https://github.com/espressif/arduino-esp32.git
Target Directory:C:/Users/[YOUR_USER_NAME]/Documents/Arduino/hardware/espressif/esp32
Do not create the espressif/esp32 folders, because they will be created automatically.
Click Clone to start cloning the repository.Wait a few seconds while the repository is being cloned.
Open the folder: C:/Users/[YOUR_USER_NAME]/Documents/Arduino/hardware/espressif/esp32/tools
Right-click the get.exe file and select “Run as administrator“.
You will see that necessary files will be downloaded and upzipped. It will take some time.
When get.exe finishes, you should see the following files in the directory.
Plug the ESP32 development board to your PC and wait for the drivers to install (or install manually any that might be required).
Open Arduino IDE.
Open Boards manager. Go to Tools -> Board -> Boards Manager… (in our case it’s the DOIT ESP32 DEVKIT V1)
Select COM port that the board is attached to (if you don’t see the COM Port in your Arduino IDE, you need to install the ESP32 CP210x USB to UART Bridge VCP Drivers)
Modify sketch1 with your SSID and password data.
Compile and upload the sketch1 to your ESP32 development board. If everything went as expected, you should see a “Done uploading” message. (You need to hold the ESP32 on-board Boot button while uploading).
Press the ESP32 on-board EN button to reboot it.
Open the Serial Monitor at a baud rate of 115200. You will get the date and time every second.

Code

First we include the libraries to connect to Wi-Fi and get time and create an NTP client. Then set our SSID and password so the ESP32 is able to establish an Internet connection and get date and time from the NTP server.

The following two lines define an NTP Client to request date and time from an NTP server.

WiFiUDP ntpUDP;

NTPClient timeClient(ntpUDP);

The following lines define an NTP Client to request date and time from an NTP server: WiFiUDP ntpUDP;NTPClient timeClient(ntpUDP);

String variables initialized to save the date and time. In the setup() we initialize the serial communication at baudrate 115200 for debugging. Then we initialize the NTP client to get date and time from an NTP server: timeClient.begin(); You can use the setTimeOffset() method to adjust the time for your timezone in milliseconds: timeClient.setTimeOffset(7200); Our zone is GMT+2.

These lines ensure that we get a valid date and time:

while(!timeClient.update()) {

timeClient.forceUpdate();

}

Sometimes the NTP Client retrieves 1970. To ensure that doesn’t happen we need to force the update. Then we convert the date and time to a readable format with the getFormattedDate() method: formattedDate = timeClient.getFormattedDate();

The date and time are returned in the following format: 2018-09-09T21:00:13Z. If you want to get date and time separately, you need to split that string. The "T" letter separates the date from the time, so we can easily split that String. The date saved on the dayStamp variable, and the time on the timeStamp variable.The time is requested and printed in every second.

Summary

We have learnt how to get date and time with the ESP32 development board. This method works if your ESP32 development board connected to the Internet. If it doesn't have access to the internet use other method - connect RTC module and get date and time from it.

Libraries

All libraries attached on the begining of this project description.
WiFi library included in your Arduino IDE.
NTPClient library included.Download, unzip and add to libraries in our PC, for example C:\Users\toshiba\Documents\Arduino\libraries. This link you can find in Preferences of Adruino IDE program which installed in your PC. You can read more about it here.

Sketch