In this project I will show you how I combined an Arduino Nano, a current sensor, an LCD, a rotary encoder and a couple of other complementary components in order to create an adjustable constant load. It features a constant current and power mode and can handle a maximum of 30V and 20A if your heatsink design can handle it. Let’s get started!
While building Arduino or any other microcontroller platform project over time the need will arise to establish communication between two of the Arduino boards or microcontrollers for data exchange and/or control. This communication could be achieved using either wired or wireless process. For wireless communication between devices, quite a number of options exist including WiFi, GSM/GPRS, Bluetooth, RF and more recent technologies like LoRaWAN among others. All of these communication protocols have their pros and cons and the situation is in which they are the best fit. For mid-range communication between two microcontrollers, for example, one of the most suitable communication protocol is RF (radio frequency) as it has a good cost to performance ratio and a very good communication range can be attained using certain modules.
Today, we will look at the radio frequency based communication between microcontrollers using one of the most popular RF communication modules; the NRF24L01 communication module.
The NRF24L01 module is a low-cost (less than$3) ultra-low power, bi-directional transceiver module. It is designed to operate within the 2.4GHz ISM band which means it can be used for projects with industrial, scientific and medical applications. The module can achieve data rates as high as 2Mbits! and uses a high-speed SPI interface in order to communicate with the Arduino and other kind of microcontroller and development boards.
Communication Between Two Arduinos Using NRF24L01 – [Link]
The Exen Mini was categorized as one of the world’s smallest 32-bit Arduino compatible boards that was launched by Nerdonic, although the board was able to get the job done in some areas it still had limited capacity, it had only 8 I/O pins. Based on the success and limitations of the Exen Mini, Nerdonic has launched a new similar board, but with improved I/O options called the Exen Proto.
Just like the Exen Mini, the Exen Proto is based on Microchip SAMD21 Cortex M0+ microcontroller allowing projects previously built for the Exen Mini board to easily migrate to the new board.
The Exen Proto is a small 32-bit Arduino compatible board based around the Arduino Zero bootloader, so projects built for the Arduino Zero won’t have problems working on the Exen Proto. The Exen Proto board is also breadboard compatible, meaning it will comfortably fit into a standard breadboard without the need for any extra connectors or manipulation.
The board is pretty small as compared to the likes of Arduino Zero and big as compared to its predecessor Exen Mini, it measures for about 14.9 x 29.8 mm and weighs just about 1.1 grams. It comes with 256KB of ROM (Program Memory), 32KB of RAM, processing speed of up to 48MHz, and up 20 I/O pins. The I/O pins include 19x PWM, 11x ADC (Analog), Serial, SPI, I2C and Digital pins. The Exen Proto can be powered by either the Micro USB port, 3.3v to 20v input pin (regulated to 3.3v with a 3.3v output pin), or directly to the 3.3v pin.
The board can be programmed with the Arduino IDE thanks to the pre-flashed Arduino Zero bootloader . The Exen Proto board is expected to come with some add-ons board or shields like a Li-Ion/Li-Po charge and discharge shield that can be charged by either the power pin or the USB port on the Exen Proto.
Below are some of the specifications for the Exen Proto board:
The Exen Proto board is currently being crowd-funded on Indiegogo and has surpassed its 1000 GBP goal, although that doesn’t matter since the campaign is a flexible campaign. The board is available for purchase from 8 GBP for a single unit excluding shipping. More information about the product can be found on the campaign page.
In the last few years, we have seen a proliferation of hardware that are designed to serve as our interface to the Internet of Things. We have seen boards like the Arduino, Raspberry, Particle, ESP32, and several others. These hardware have made developing and scaling for the Internet of Things quite easy for developers and product managers. Despite the fact, these hardware are meant for the cloud-based applications (IoT Applications) most of them don’t get developed with web-based programming but traditional programming languages. obniz is a hardware for the internet of things that is designed with the Web in mind.
The obniz hardware is made up of 12 IOs, each IO can handle up to 1A making it easy to connect at least 1 motor to all pins at the same time. It supports WiFi 802.22 b/g/n and Bluetooth Low Energy which is made possible by the onboard ESP WROOM 32, a 128 by 64 px OLED screen for display applications, a switchable 5V or 3V on each I/O.
One major benefit of using obniz is the nature of its IO pins. All 12 pins can be used for A/D (Analog and Digital Processing), UART, SPI and others. There are no specialized pins, they all have the same capabilities. Although there is a limit to the total number of UART pins that can be used, but A/D and others can be used on all 12 pins at the same time. Just like Arduino, it is short protected.
Getting started with obniz is easy with these 3 steps:
Connect obniz to Wifi
Connect motors sensors to your obniz
Scan a QR code on your obniz that will direct a user to a program page.
An easy to solder Arduino and CircuitPython compatible module meant for simplifying the creation of your own custom circuit boards. The project is live on kickstarter.
The SAMD HCC Module is an Arduino compatible, ready and easy to solder, surface mount programmable micro-controller module. Its purpose is to simplify the process of creating and building your own custom circuit boards without the need of worrying about soldering small fragile components, while still retaining all of the benefits of a tiny, lightweight, and low power micro-controller. Think of it as a way to bridge the gap between breadboard prototypes and full on “solder yourself” custom circuit boards. This is the simplified missing link. You use the module in combination with your custom circuit boards, to solder it directly to the board. No need for programming headers, power supplies, or FTDI chips.
One of the downsides of using an Arduino board in projects is the fact that it comes with some other components which may not be needed after the code has been uploaded to the board. These peripherals consume a considerable amount of power which affects the overall power consumed by the project, thus increasing the rate at which the energy stored in batteries used for powering such project. This makes the Arduino boards not suitable for projects which are required to run on battery for long period of time like a weather monitoring station as there will be a need for constant battery change due to the high consumption rate of the device. One way to solve this problem while still retaining the “ease of use” that accompanies the Arduino platform is to use the ATMEGA328p microcontroller used on the Arduino Uno itself. By using this chip, we eliminate the power loss of other components that make up an Arduino board and thus the battery will last for longer time.
Low-Power Arduino Weather Monitoring Station – [Link]
The World’s Smallest Arduino has been one of such title that is heavily contested by so many Arduino compatible boards. We have seen several boards that have claimed the title in one way or the other such as boards like pico, µduino, beetle, nerdonic or even digispark. µduino seems to be the world smallest Arduino compatible board among all measuring at only 0.5″ by 0.5″.
So if µduino is the smallest, what is Piksey? Piksey is most likely the World’s Smallest Arduino 328 Clone measuring about 0.8 inches by 0.8 inches. Even though the Piksey board is slightly larger than the µduino version, it is still the true smallest Arduino clone. The Atmega 328P processor powers the Arduino Uno board and the same processor is what runs on Piksey, unlike µduino which is based around Atmega32U4 processor.
Just like the Arduino Uno, the Piksey extends all the 13 digital IO pins and all 5 analogue pins out; this will make the board fully working with all existing Arduino Uno based codes, libraries, and even shields. So yeah, the Piksey is the World Smallest Arduino 328 Clone.
The Piksey is a new Arduino compatible development board that is developed by BitsNBlobs and currently running a kickstart campaign. The new board is a tiny board as compared to the real Arduino Uno board and still pack similar features. The board is as small as a crown cap and yet powerful.
At the heart of the Piksey board is the all famous Atmega328P running at 16MHz, 32KB of Flash, 1KB of EEPROM, and 2KB of SRAM. Just like the Arduino Uno board, the Piksey board is also a 5V rated board. It is breadboard friendly and provides up to 16 pins for digital and analogue purposes.
The board is powered via a micoUSB port and can take in a max of 18V through the inbuilt voltage regulator. The board comes with an inbuilt USB-serial converter for programming the device.
Below are summarized the features of the board:
Size: At 20x20mm, the Piksey core is smaller than a crown cap!
Breadboard Compatible – 16 breadboard compatible pins, rest available on 1.27mm header
Connectivity: micro USB for programming and power
Others: Contains power and general purpose LED
Reset Switch: A Tactile switch for module reset
The Piksey board will find use in applications that need to work with tight spaces, and it even comes without any headers. The Piksey crowdfunding campaign is now active on Kickstarter with pledges starting from £8 to £20.
The Pixl.js is a Bluetooth LE device with a connected display and is based around the Nordic Semiconductor nRF42832 SoC. The nRF52832 SoC is a powerful, highly flexible ultra-low power multiprotocol SoC. The nRF52832 SoC is built around a 32-bit ARM® Cortex™-M4F CPU with 512kB + 64kB RAM. The embedded 2.4GHz transceiver supports Bluetooth Low Energy, ANT, and proprietary 2.4 GHz protocol stack.
The Pixl.js can talk and control other Bluetooth LE devices making it a good option for mesh networking applications. It can act as a wireless display, a conference badge, or as a notification message console. The board measures about 60mm × 53mm × 15mm and the LCD is a 128×64-pixel monochrome display that features a white backlight. The board is very power friendly and can be powered from an attached micro USB connector and a CR2032 coin cell battery which can give it a whopping 20-day life of juice.
The Pixl.js board comes with some similar Arduino footprint. It has a standard Arduino GPIO header beneath it making it able to interface with existing Arduino shields. The board packs a lot of features and doesn’t even require a driver when plugged into a computer.
The Arduino has been a household name in the hardware market for a long while now and many vendors have released various add-on devices usually called Shields to expand the functionality of Arduino. One such add-on device is the newly launched Sunflower shield that will allow users to add a touchscreen display to any Arduino project.
A touchscreen is one of the most intuitive and straightforward way of adding user interaction to a project allowing one to remove the need for buttons or some other form of input, and this could be achieved with the Arduino in several ways. Combining a display and a touchscreen to use with an Arduino has been somewhat challenging and tricky, but the Sunflower Shield from creator Paul Bartek and his team will make this easier to achieve.
The Sunflower Shield is a 3.5” capacitive touchscreen that plugs into any standard Arduino board as a normal Arduino shield. The board is a 5V dependent board so it won’t work with any 3.3V based Arduino boards like the 3.3V Arduino Pro. The shield is made up of a 5-point Multi-touch Capacitive Touch Screen making it capable of building gesture control applications. It also supports a portrait and landscape display orientation, a temperature reading through a K-type thermocouple that is shipped with it, provides support for audio output and comes with an 8-ohm speaker.
The Sunflower shield is slightly larger than an Arduino Uno and comes with four mounting holes so you can easily secure the device to an enclosure. It comes with onboard micro SD card slot for application storage.
The following are some of the features of the shield:
Easy to use 5-point Multi-touch Capacitive Touch Screen
High Brightness White LED Backlight (660 cd/m2)
Supports Portrait and Landscape Display Mode
Smooth Animations at up to 60 frames/second
LED Driver with Pulse Width Modulation (PWM)
True 24-bit Color
On-board Bridgetek FT813 Graphics Controller IC with Display, Touch and Audio Functionality
On-board Pulse Width Modulation (PWM) Audio and Speaker Amplifier
Terminal Block with Push-Buttons for Driving an External 8Ω 1W Speaker
Micro-SD Socket for Application Storage
On-board Maxim MAX31855 K-type Thermocouple Amplifier (-200°C to +700°C with an accuracy of ±2°C)
On-board Thermocouple Contacts to Accept a Standard Thermocouple Connector
Terminal Block with Push-Buttons for Solid-State Relay (SSR) Control
4 x 3.2mm Mounting Holes Enabling Standard M3 or #6-32 Screws
The shield is currently being crowdfunded on Kickstarter with campaign already exceed their minimum amount requirement and is available for pre-order starting at a $90 pledge level. It is estimated that the board will be available for delivery around September 2018.
The Sunflower Shield will allow makers to add a 3.5″ (QVGA) TFT LCD Display with capacitive touch to their Arduino projects.