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IoT development boards comparison: R-Style Lab’s picks
An IoT microcontroller unit (MCU) or development board is a prototyping solution that features low-power processors which support various programming environments, collect sensor data using firmware and transfer it to an on-premises or cloud-based server. Also, there are more powerful hardware prototyping solutions like Raspberry PI and BeagleBoard which are called microcomputers. Such microcontrollers are enhanced with quad-core processors, run a classic operating system and support multiple types of output devices.Energy efficiency is one of an MCU’s key performance characteristics; microcontrollers that consume a lot of power can’t be used as the core for low-power or wearable IoT devices (nobody wants to recharge a smartwatch three times a day). Let’s compare several energy-efficient MCUs and see which one suits your needs best.
ESP8266The low-cost microcontroller is one of the most popular prototyping solutions on the market. Here are some of its crucial advantages:
- Wi-Fi support (which basically means IoT software development companies can connect the board to the Internet without an intermediary gateway that, for example, enables connectivity in Bluetooth solutions);
- Flexibility for rapid development with either native IDEs such as ESPlorer (provides an opportunity to code in a scripting language like LUA) or Arduino (C/C++ environment);
- Out-of-the-box support for the MQTT protocol (helps vendors integrate IoT hardware into complex device networks comprised of thousands of sensors).
ApplicationsESP8266 powers IoT devices with a simple logic (which use either Wi-Fi or wire connection).
Power ConsumptionHere’s where ESP8266 wins the microcontroller board comparison game. Judging from our experience, the MCU can consume anything between 100 mA (Wi-Fi operation and data transmission) to 10 mA (deep sleep mode); the amount of energy consumed by the board actually depends on the setup and harness. With additional circuits, the deep sleep mode power consumption can be further reduced to less than 0.1 mA (typically, 0.07-0.08mA). It means that a 3000 mAh device (the size of an Android smartphone battery) can keep the MCU going for about 3 years!
ESP32Being the next generation of EPS8266, the MCU possesses all of the above-mentioned characteristics – and boasts some major improvements (more RAM, more hardware, more cores and, as a result, better overall performance). Check out ESP32’s key characteristics:
- The microcontroller deploys two CPU cores operating at a frequency of 160 Mhz (compared to the single-core 80 Mhz EXP8266 board);
- 512 Kb RAM (which enables the MCU to deal with certain encryption algorithms, thus expanding its application scope);
- Bluetooth 4.2 connectivity (the board can serve as a gateway for Bluetooth-only devices).
ApplicationsThe ESP32 microcontroller is also employed by simple logic devices, as well as gadgets that use BLE connectivity and some security modules.
Power consumptionAccording to the measurements we’ve made while working on several IoT projects, the microcontroller uses about 150mA with WiFi and Bluetooth data transmissions active at the same time, 5 mA if the deep sleep mode is activated and around 0.04 mA with reduced schematics. When measured against a 3000 mAh smartphone battery, the device can potentially last for around 5 years.
ATmega328PAlthough the popularity of the MCU has declined over the years due to performance issues, ATmega328P variations still power Arduino boards and their multiple clones. The microcontroller operates at a frequency 8-16 Mhz and lacks wireless interfaces. If you consider using the MCU independently, it will require extra harness to perform the intended functions.
ApplicationsATmega328P facilitates sensor data collection, light intensity measurement and serial communication. According to Pavel Shylenok, CTO at R-Style Lab, Atmel AVR microcontrollers will soon be driven out of the market since modern IoT devices require more connectivity and performance capabilities.
Power consumptionThe R-Style Lab team has been using ATMega328P MCUs for more than 10 years; based on our observations, the MCU’s power consumption ranges from 50mA for Arduino boards (with a 9V battery running out in 24 hours) to 0.004 mA for MCU-only schematic – which, again, makes a 3000 mAh battery last for 50 years. No battery lives that long, but you get the idea, right?
STM32F469These new-generation microcontrollers feature Cortex-M4 processors with float-pointing units (FPUs) supporting heavy calculations. STM32F469 boards operate at a frequency pf 180 Mhz; they are designed for wearables and LCD screen interfaces and enable IoT application development specialists to create advanced graphical UIs. If you want to build a wearable gadget, STM32F469 is the way to go. However, the MCU is new to the dev community; if you encounter a performance issue, few developers will be able to help you (so choose your vendor wisely).
ApplicationsSTM32F469 boards are largely employed by data processing units, sensor controllers and wearable gadgets.
Power consumptionAlthough the official STM32F469 documentation suggests the power consumption of around 50 mA in full operational mode, the use of extra harness around the chip increases the number twofold. With the deep sleep mode enabled, the MCU consumes just 0.2 mA. Take the 3000 mAh battery, and you’ll get a 12-months battery life. With wearable gadgets like Apple Watch (205 mAh battery), the battery life will drop to somewhere between 7-10 days.
According to Gartner, there will be 8.4 billion connected devices by the end of 2017. Still, the Internet of Things remains a novelty concept and, therefore, requires an innovative approach to hardware and software development. The choice of a microcontroller and sensors entirely depends on your gadget’s feature set and intended functionality, and there’s only one way to pick the best microcontroller IoT board for your project – that is, partner with an experienced vendor and create Proof of Concept. This article, however, will help you limit the number of options and…save time.