This guide shows how to read temperature from multiple DS18B20 temperature sensors with the ESP32 using Arduino IDE. We’ll show you how to wire the sensors on the same data bus to the ESP32, install the needed libraries, and a sketch example you can use in your own projects. This tutorial is also compatible with the ESP8266 and the Arduino boards.
ESP32 with multiple DS18B20 temperature sensors – [Link]
Simple LED matrix Clock based on the popular ESP8266 with Real Time Clock module and time synchronization over WiFi from an NTP server.
One note on the RTC module, apparently it also has the ability to charge the battery, however that’s not a good idea when using a CR2032. One possible solution would be to cut the trace marked on the image in order to disable the charging part of the circuit.
Back in March 2016, Espressif Announced the ESP8285 Wi-Fi Chip, a supposed killer of the favorite ESP8266 chip. The new chip is an ESP8266, but with the flash memory onboard – 1MB flash memory. Espressif’s ESP8285 delivers highly integrated Wi-Fi SoC solution to meet users’ constant demands for efficient power usage, compact design and reliable performance in the Internet of Things industry. With the complete and self-contained Wi-Fi networking capabilities, ESP8285 can perform either as a standalone application or as the slave to a host MCU. When ESP8285 hosts the application, it promptly boots up from the flash. The Chip is also ultra-small as compared to the ESP8266 making it suitable for applications like in wearables.
Taiwan based Blkbox may have designed the world’s smallest WiFi IoT module with their Espressif Systems ESP8285 based BB-E01P module which is pin-compatible with the ESP-01 module, and measuring just 10×14 mm. Several ESP8285 modules have been released, but the Blkbox version is probably the smallest ever. Itead Studio’s PSF-A85, an ESP8285 Wireless Module measures just 14mm*135mm, and even the Electrodragon ESP8285 WiFi module measures 15.5mm x 17.8mm. With this, the Blkbox module might be the smallest we currently have. The BB-E01P is the equivalent of the Blkbox predecessor BB-E01 with reduced dimensions.
The following are the specification of the Blkbox BB-E01P ESP8285 WiFi module:
Wi-Fi Packet Monitors are usually a computer program or sometimes a piece of computer hardware that can be used to intercept and log traffic over a Wi-Fi network. My favorite software tool of all is the popular Wireshark which I have used several times for hacking Wi-Fi based hardware, like integrating the common Wi-Fi smart socket with OpenHAB. Packet monitor tools give the possibility of seeing what type of data is being sent out by a wireless device and provides us with the chance of conjoining that data for our purpose.
Apart from the use of software for packet capture, we can also leverage hardware for this. The Espressif Systems ESP8266 and the ESP32 modules have been a go-to module for a lot of makers regarding Wi-Fi/IoT applications. Stefan Kremser aka Spacehuhn who first launched an Esp8266 based packet monitor, earlier last year has released an improved opensource ESP32-based packet monitor which is available on Tindie and Aliexpress for purchase.
The original Packet Monitor board put together by Spacehuhn is based around the ESP8266 and allowed you to see data packets flying around you in real-time. It tells how many Wi-Fi packets are sent every second and on which channel. It is also able to display the result on a small OLED Screen. The ESP32 version comes with some new features.
Then new ESP32 Packet monitor includes some new features to the existing ESP8266 Packet monitor. It adds an SD card support for capturing and saving traffic data with the possibility analyzing that data at other time, unlike the ESP8266 which shows only the current packet only, the ESP32 version displays an average RSSI (Received Signal Strength Indicator), and of course offer an improved performance due to the increased power of ESP32. It is built around the ESP32-Wrover module, which has 4MB Flash and 4MB PSRAM.
Like it’s predecessor ESP8266 PacketMonitor, the ESP32 PacketMonitor32 has a 1.3-inch OLED for displaying the traffic data. It can be powered via its micro USB jack or with a Lipo battery that also includes both over-charging and over-discharging protection. The board comes in two different versions, the one with an external (IPEX) antenna support, and one with a PCB antenna support. The one with the IPEX antenna offers increased range but won’t work without the antenna connected. It is possible to run on your code on the board or use the Spacehuhn packet monitoring software.
The PacketMonitor32 board is avaiable now for purhase on Tindie, and on AliExpress, with a price tag of $19.
In this post I’m going to show you how you can monitor the power consumption of your battery driven (ESP8266/ ESP32) device. Measuring the power consumption over a full activity/ sleep cycle is the precondition to optimize your code for a longer battery runtime. Only with a reliable tool you can decide which code changes lead to less consumption. In a later post we’ll look at some tweaks we can apply to the code to get a few more days out of the battery.
RDA’s RDA5981 is a fully integrated low-power WiFi chip from RDA Microelectronics. RDA5981 is a fully built WiFi chip highly intended for applications in the areas of a smart home, audio applications and IoT applications. The RDA5981 is being used in devices running Baidu DuerOS, the Chinese alternative to Amazon Alexa or Google Assistant.
During the annual event of China’s semiconductor industry IC China 2016, RDA Microelectronics announced the RDA5981 during the event with promises of it reducing the size, power consumption, development costs of a smart device.
The RDA5981A is a low power MCU with IEEE802.11b/g/n MAC/PHY/radio integrated into one chip. The RDA5981 is powered by the ARM Cortex M4 plus FPU/MPU core running at 160MHz speed, a high performing processor for that application type. It has up to 288KByte of internal SRAM and additional 160Kbyte SRAM for Wi-Fi stack and flash cache but with only about 192Kbyte available for the user. It has up to 8MB of Flash, 2x ADC with a 10bit resolution, 8x PWM (Pulse Width Modulation), 4x SPI (Serial Peripheral Interface) with a maximum clock frequency of about 20MHz, one I2C, 2x I2S, 2x UART and a total of about 14 GPIO Pins.
Concerned about Security, the RDA5981 has an onboard hardware cryptographic accelerator supporting AES/RSA, and a True Random Number Generator (not the one you use software to generate), and lastly a CRC accelerator for improved performance. It includes an onboard TCP stack which could either support SSL, TLS or even both.
Unlike the ESP8266, one the maker’s favorite Wi-Fi module, the RDA5981 includes USB2.0 features.
RDA5981 A/B/C processor specifications:
CPU – Arm Cortex-M4 +FPU/MPU core @ up to 160 MHz
Up to 448 KB SRAM for network stack and application
User available memory is 192Kbyte
Up to 32Mbit SPI flash
Support 64M PSRAM expansion
2.4 GHz 802.11b/g/n WiFi up to 150 Mbps with 20/40 MHz bandwidth
The board can be programming with AT commands or using mBed and the company provides support for FreeRTOS and mbedOS5.1 for the chip. More information about the device specification can be found on the Electrodragon Wiki
The RDA5981A IC is expected to sell for around $1 and an RDA5981A Wi-Fi module is available for sale at $1.92 from Electrodragon.
This instrucatables show how to make an ESP8266 version WiFi Analyzer clone.
WiFi Analyzer is a handy app in Android, it help to visualize the WiFi signal information around you. It is very useful for helping select a right channel for setting a new AP. If you selected a channel that as same as another AP near you, you may encounter interference and degrade the network performance.
Using e-paper for a weather station is an ideal solution, as the data does not need to be updated often. By default, the station reaches out every 20 minutes for new data over WiFi and then updates the display. Daniel Eichhorn already has published kits for OLED (see “WiFi OLED Mini Weather Station with ESP8266“) and touch display (see “WiFi TFT Touch LCD Weather Station with ESP8266“). I like them both, but especially the TFT one is very power-hungry and not really designed to work from batteries. What I would like is a station which can run for weeks.
ESP8266 based e-paper WiFi weather station – [Link]