June 26, 2019 at 13:35Alternatives to the Raspberry Pi
February 29, 2012 our world has changed a little for the better. The Raspberry Pi Foundation has announced the start of sales of small single-board computers under the brand name Raspberry Pi. At the beginning of sales, buying a device was not easy, but little by little the market was saturated and from July 2012 you could finally just go to the store and buy or order the first Malinka via the Internet, the Raspberry Pi Model B is a single-board Linux computer with a 700 MHz processor, 0.5 GB RAM, USB, Ethernet and 26 GPIO pins, allowing you to connect external boards, input-output devices and actuators. The device, built on the basis of a relatively inexpensive four-layer board, with low cost, with an end-user price of $ 35, is so well made that the alpha version of the Raspberry Pi Model B won the Hardware Design nomination for ARM TechCon 2011.
The computer developed, the family grew. While the main branch received more and more powerful processors and modern hardware (for example, the 3B + model has a quad-core 64-bit processor with a clock frequency of 1.4 GHz, 1 GB of RAM, four USB ports, Wi-Fi 802.11ac and Bluetooth 4.2) In addition, the Raspberry Pi Zero family was developed with a motherboard reduced to 65 × 30 mm and priced at only $ 5 ($ 10 for the version of the Raspberry Pi Zero W with Wi-Fi 802.11n).
Recently, the Raspberry Pi Foundation introduced a new version of its mini computer - Raspberry Pi 4. The “four” announced a quad-core 64-bit Cortex-A72 processor with a clock speed of 1.5 GHz as part of the SoC Broadcom BCM2711, two USB 2.0 and two USB 3.0, Bluetooth 5.0, support two monitors. GPU VideoCore VI is capable of processing 4K video stream with 60 fps. Now, finally, you can choose the amount of RAM - 1, 2 or 4 GB LPDDR4 SDRAM.
Sold by millions of copies, the Raspberry Pi has pioneered a whole new market for portable single-board computers and an example for a number of alternative designs. Let's see, using Raspberry Pi 3B + as a starting point (Raspberry Pi 4 is not yet available for purchase, I hope the Quartet will be available soon) that we can offer competitors whose evolution threw them into quite unusual ecological niches, and how much we, as buyers, will have to pay for this research. In descriptions of competing computers, we will try to mention all available hardware advantages of the participants, if possible; this makes the description somewhat dry, but you can quite definitely choose the computing core for your future project.
It differs from the Raspberry Pi 3 for the better by the presence of 2 GB of RAM and the Mali-450 GPU accelerator integrated in the SoC AllWinner H5, which allows you to play 2K video. Among the interesting features, it is worth noting the presence of an IR receiver; the board can be controlled from the remote control or from some models of cell phones with a built-in IR LED, for example, Redmi Note 7. Of the non-standard equipment, there is also a built-in microphone and a CSI video interface that supports video stream up to 1080p at 30 fps.
On a board with a size of 98 × 60 mm, there was a place for a slot for memory cards (up to 32 GB), Wi-Fi 802.11 b / g / n, Bluetooth 4.0, gigabit Ethernet, four USB (three USB 2.0 Host and one USB 2.0 OTG) and forty-contact GPIO comb. There is even a separately derived UART with TTL levels, so you can watch Linux boot details in the terminal. From the audio equipment, in addition to the microphone mentioned above, there is also a linear output and an audio output in HDMI. The video accelerator supports OpenGL ES 2.0 and OpenVG 1.1. Among the supported OS are Ubuntu, Debian and Android 5.1.
In general, I must say that Orange Pi remains one of the most successful competitors of Raspberry. Orange also became the progenitor of a whole line of heterogeneous single-board computers, including Orange Pi 4G-IOT(with GSM / GPS / LTE module on board) and Orange Pi Zero (can optionally be powered by PoE, so you can drop it into a distant segment of the Ethernet network without even supplying a separate power supply).
UPD : about the cons specifically Orange Pi 2G-IOT there is a separate article id_potassium_chloride . Be on the alert!
Together with Orange, Banana developed by the Chinese company SinoVoip is another “fruit” branch that has grown well since the advent of Raspberry. Following in the Raspberry wake, Banana consistently released the Banana Pi M1, M1 Plus, M2 Plus, M2 Ultra, M2 Zero, M3 models.
The current flagship Banana Pi M3 is based on the eight-core Allwinner A83T SoC (ARM Cortex-A7 processors, PowerVR SGX544MP1 graphics processor), clocked up to 1.8 GHz and working in an environment of 2 GB of RAM and 8 GB of flash memory. In addition to gigabit Ethernet, two USB, Wi-Fi 802.11 b / g / n, Bluetooth 4.0 and HDMI, there is SATA on the board. Like the Orange Pi Prime, the M3 has an IR receiver, CSI video interface, debug UART, microphone, line-out, and HDMI audio output. Unlike Orange, Banana has a MIPI DSI display interface combined with I2C for the touch screen. Naturally, there is a forty-contact GPIO comb.
The Rock64 single-board computer is already equipped with 4 GB of RAM, serving the 64-bit ARM Cortex A53, the video subsystem is able to cope with 4K stream at a frequency of 60 fps. The device is powered by POE. The graphics subsystem ARM Mali 450MP2 corresponds to OpenGL ES 2.0, OpenVG1.1. Debian, Cent OS, Fedora, and Android 8 were ported to Rock64; in general, it should be noted that the developers and enthusiasts of this computer ported a large number of Linux-based OSes to it. Rock64 has abundant, detailed documentation and a lively, active community, so, taking into account good hardware specifications and sparing prices, this single-board is a good candidate for replacing the Raspberry Pi 3 in projects with increased hardware requirements.
Rock64 developers generously poured 64 GPIO pins, outputting Ethernet signals to them, so if you plan to control branched external peripherals on a single-board, take a closer look at this computer. In addition, there is USB3.0.
Rock64 has an older brother, ROCKPro64 , built on the eight-core 64-bit Rockchip RK3399 (four ARM Cortex A53 plus two ARM Cortex A72), with 4 GB LPDDR4 and two USB 3.0. PINE64, a producer of Rock64 and ROCKPro64, is generally a worthy example of a DIY business. The guys go the way, beaten by pioneers like Sparkfun or Adafruit, who have shown that you can supply your development with a complete set of design documentation and at the same time be a commercially profitable enterprise.
Tinker is built on the basis of SoC Rockchip RK3288 with a quad-core ARM Cortex-A17 processor and runs on TinkerOS based on Debian, you can install Android. The Mali-T760 MP4 video processor supports OpenGL ES 3.1, OpenCL 1.1, Renderscript, and Direct3D 11.1.
The GPIO comb got a color coding, so when connecting external devices it will be a little more difficult to make a mistake. A small passive radiator glued to the processor case, which is purchased separately from competing boards, is already carefully included in the standard kit.
The Asus Tinker board S had a younger brother, the Asus Tinker board without on- board flash memory, but it did not have much success and has now practically disappeared from the market.
Renegade, or the Libre Computer ROC-Rk3328-CC Renegade, is designed to be as similar to Raspberry as possible; for example, you can place the ROC-Rk3328-CC directly in the case purchased for Malinka.
SoC RK-3328 is built on the basis of a quad 64-bit ARM Cortex-A53 processor with an operating frequency of up to 1.5 GHz. SoC is the same as in Rock64, so here you also have the same Mali 450MP2 GPU with an operating frequency of 500 MHz. When ordering, you have the opportunity to vary the amount of RAM, you can choose 1 GB DDR4 (then the computer will cost you $ 35), 2 GB for $ 50 or 4 GB for $ 80. Of the operating systems, Ubuntu 18.04, Debian 9, OpenMediaVault 4, Station OS, and Android 7.1 are currently available.
Like the Asus Tinker board (without the S index), Renegade does not have on-board flash memory, you will have to use a microSD card slot or eMMC interface.
Libre Computer is one of the manufacturers that has shown good growth in the new business niche created with the advent of the Raspberry Pi. In addition to Renegade, in the summer of 2018 Libre Computer began production of Renegade Elite , a single-board computer Libre Computer ROC-Rk3328-CC Renegade Elite based on SoC Rockchip RK3399 with a six-core processor (two ARM Cortex-A72 cores and four ARM Cortex-A53) and GPU ARM Mali- T860 MP4, which has two USB 3.0 Type-C ports, a 60-pin PCIe slot, 128 MB on-board memory and a 60-pin GPIO comb. Renegade Elite has optional PoE support and can run Linux 4.19 or Android 8.
Given its relatively low price, the Odroid H2, built on the basis of 64-bit 4-core Intel Celeron Gemini Lake J4105, may well qualify for a piece of the market niche occupied by single-board computers based on ARM processors. If you prefer x86-compatible solutions, this small motherboard with a size of 110 × 110 mm, with passive cooling, Intel UHD Graphics 600 GPU, PCI-E gen2 bus and dual SATA 6 GB / s will be to your liking.
According to the Intel specification, the maximum RAM size is 8 GB (SO-DIMM DDR4 2400 MHz, not included, purchased separately, as for any "pisyuk"), but the manufacturer Odroid H2 claims to have stuck two 16 GB strips (total 32 GB) and everything worked perfectly. Of course, the board supports Windows 10 / Linux x64, DirectX 12, OpenGL 4.3, OGL ES 3.0, OpenCL 2.0.
As an alternative to Odroid H2, you can consider UDOO X86 (there are options on Intel Pentium N3710 2.56 GHz and Intel Celeron N3160 2.24 GHz).
You do not need to be Dr. Xavier from the People X franchise in order to hear the mental exclamations of some readers right now: “Why what ...! Where is Malinka and where is Arduinka? It’s the same as comparing a cheetah with E. coli! ” Yes, yes, that's right, Raspberry Pi and Arduino are in significantly different market niches, but if you look at the summary tables at the end of the article, you will find one point that makes two of these very diverse developments related. And this item is the price. Yes, they are asking for $ 31 for the Arduino Mega 2560 Rev3, and $ 42 for the Arduino Uno WiFi Rev2 (as the quickest readers have guessed, the board is equipped with Wi-Fi).
Let's take a look at the hardware stuffing of this “single board computer” (or do you need to omit the quotation marks?). 8-bit microcontroller ATmega2560 with a clock frequency of 16 MHz, 256 kbytes of flash memory (of which 8 kbytes are occupied by the bootloader), 8 kbytes of RAM and 4 kbytes of non-volatile memory. Of the communication capabilities, instead of the usual single-board computers Ethernet, Wi-Fi and Bluetooth, which are familiar from the previous compared models, in the case of the Arduino Mega 2560 we will have to mention four UARTs, one of which is connected to the built-in USB-UART converter. The converter itself, by the way, is also implemented on the AVR microcontroller, ATmega8U2-MU, but this is not important, there are options with specialized FTDI chips. Generally, the board’s characteristics (like a permissible current of 20 mA per output or the ability to configure 15 GPIOs as PWM outputs) predictably repeat the characteristics of the microcontroller on which it is built. The manufacturer himself positions Arduino Mega as a good basis for hobby projects related to 3D printing and robotics.
The Arduino world has its own analogue of the Raspberry Pi Zero microcomputer, this is the Arduino Nano board . Built on the basis of the ATmega328P microcontroller, with a size of 18 × 45 mm, the device boasts 2 kilobytes of RAM and 32 kilobytes of flash memory, 16 MHz clock and 22 GPIO pins, 6 of which can work as PWM outputs.
In general, the Arduino series is quite simple in terms of its hardware device, so even when I was in a hobbial-melancholic state of mind, I sat down and drew (with the help of Altium Designer) my version of Arduino Nano. Improved noise immunity by incorporating the USBLC6-4SC6 protective assembly into the USB circuit, finalizing the USB-UART converter in accordance with the AN-146 USB Hardware Design Guidelines for FTDI ICs and minor modifications to the circuit in accordance with AVR042: AVR Hardware Design Considerations. Added a gamma radiation sensor on PIN diodes ("Why? Because I can!"). So that the relatively high-voltage power supply of the radiation sensor did not have to be dragged from the outside, a small voltage multiplier was added, controlled by a microcontroller. Description of the resulting board is here., and the full project archive (with all Altium sources and libraries) you can download here .
In general, of course, it’s a little strange that Arduino did not die out after the heyday of Raspberry and its clones. I think that the popularity of Arduino is not least due to what happened in the early to mid 2000s “shot” of the AVR architecture, developed by Atmel. Not to say that the market for 8-bit microcontrollers was empty, there was a pretty good choice between i51 and PIC, and 16-bit MSP430 was available for energy-saving solutions.
But the microcontrollers of the AVR series, combining the new successful RISC architecture, executing instructions in 1 clock cycle (which was undoubtedly a blow under the breath of the then i51, executing instructions in 12 clock cycles) and just in time for the cheaper internal flash memory, were a supernova. even against the background of not weak old-timers. As I remember now, with what pleasure I repeatedly flashed a flash AVR microcontroller; There was no JTAG in it, and it was impossible to look at the registers directly during operation, but compared to the pair of H1830BE51 + EPROMs with ultraviolet erasure, it was just a new future.
Maybe it's the Arduino IDE, which facilitates software development, or the friendly community of Arduino-compatible developers. In any case, Raspberry supporters have something to think about. Maybe the development threshold for modern A series ARM processors is too high, and therefore many developers, especially hobbies, are not ready to spend so much time mastering all the tricks of working with modern processors. Let's hope that something like STM32CubeMX appears (software for STM32 microcontrollers of the ARM Cortex-M0 ... Cortex-M4 series, which greatly simplifies the initial setup of the controller) and electronics lovers are also slowly migrating to the Raspberry camp.
I will not bore the reader with a further listing of all possible alternatives to the Raspberry Pi. I think you understand the main thing - there are alternatives, and options for a variety of hardware configurations and price categories are available to order: from boards with a price tag of up to $ 50 and hardware stuffing, very similar to the original Raspberry to more expensive devices, the price of which is gradually increasing in parallel with growth hardware capabilities.
In pursuit of the considered single-board computers casually, in a telegraph style, I will also mention such developments as Odroid-C2 ($ 59); Odroid-XU4 ($ 80, you can add the OGST Gaming Console Case for Odroid XU4 for $ 25) Pine A64-LTS ($ 32); NanoPi NEO4 ($ 45); Cubieboard4 CC-A80with PowerVR G6230 GPU ($ 130); Nvidia Jetson Nano on the quad-core Tegra X1 ($ 140); BeagleBoard X15 with two Ethernet ports and a combination of PowerVR GPUs with 4 GB of RAM ($ 263); LattePanda Alpha on Intel Atom X5-Z8350 ($ 240); Hikey 960 on an eight-core Kirin 960 with four ARM Cortex A73 cores clocked up to 2.3 GHz and four ARM Cortex A53 cores up to 1.8 GHz ($ 268) and BBC micro: bit as a possible replacement for Arduino ($ 15).
Summary table, main parameters
Summary table, memory and interfaces
In recent years, a lot of interesting things have been happening on the single-board computer market. New models are constantly appearing and disappearing in all niches, starting from Arduino, affecting Raspberry and ending with motherboards compatible with 8th generation Intel processors. For example, right now on Kickstarter there is a campaign of UP Xtreme, an Intel-compatible motherboard, and the development of the promising Galileo platform, on the contrary, has been scaled down. The developers of Renegade Elite, by the way, also raised funds to launch production through the Indiegogo crowdfunding platform. So if you want to keep abreast of the latest developments in the field of single-payers, sometimes go over the sections “Technology” of crowdfunding sites.
The computer developed, the family grew. While the main branch received more and more powerful processors and modern hardware (for example, the 3B + model has a quad-core 64-bit processor with a clock frequency of 1.4 GHz, 1 GB of RAM, four USB ports, Wi-Fi 802.11ac and Bluetooth 4.2) In addition, the Raspberry Pi Zero family was developed with a motherboard reduced to 65 × 30 mm and priced at only $ 5 ($ 10 for the version of the Raspberry Pi Zero W with Wi-Fi 802.11n).
Recently, the Raspberry Pi Foundation introduced a new version of its mini computer - Raspberry Pi 4. The “four” announced a quad-core 64-bit Cortex-A72 processor with a clock speed of 1.5 GHz as part of the SoC Broadcom BCM2711, two USB 2.0 and two USB 3.0, Bluetooth 5.0, support two monitors. GPU VideoCore VI is capable of processing 4K video stream with 60 fps. Now, finally, you can choose the amount of RAM - 1, 2 or 4 GB LPDDR4 SDRAM.
Sold by millions of copies, the Raspberry Pi has pioneered a whole new market for portable single-board computers and an example for a number of alternative designs. Let's see, using Raspberry Pi 3B + as a starting point (Raspberry Pi 4 is not yet available for purchase, I hope the Quartet will be available soon) that we can offer competitors whose evolution threw them into quite unusual ecological niches, and how much we, as buyers, will have to pay for this research. In descriptions of competing computers, we will try to mention all available hardware advantages of the participants, if possible; this makes the description somewhat dry, but you can quite definitely choose the computing core for your future project.
Orange pi prime
It differs from the Raspberry Pi 3 for the better by the presence of 2 GB of RAM and the Mali-450 GPU accelerator integrated in the SoC AllWinner H5, which allows you to play 2K video. Among the interesting features, it is worth noting the presence of an IR receiver; the board can be controlled from the remote control or from some models of cell phones with a built-in IR LED, for example, Redmi Note 7. Of the non-standard equipment, there is also a built-in microphone and a CSI video interface that supports video stream up to 1080p at 30 fps.
On a board with a size of 98 × 60 mm, there was a place for a slot for memory cards (up to 32 GB), Wi-Fi 802.11 b / g / n, Bluetooth 4.0, gigabit Ethernet, four USB (three USB 2.0 Host and one USB 2.0 OTG) and forty-contact GPIO comb. There is even a separately derived UART with TTL levels, so you can watch Linux boot details in the terminal. From the audio equipment, in addition to the microphone mentioned above, there is also a linear output and an audio output in HDMI. The video accelerator supports OpenGL ES 2.0 and OpenVG 1.1. Among the supported OS are Ubuntu, Debian and Android 5.1.
In general, I must say that Orange Pi remains one of the most successful competitors of Raspberry. Orange also became the progenitor of a whole line of heterogeneous single-board computers, including Orange Pi 4G-IOT(with GSM / GPS / LTE module on board) and Orange Pi Zero (can optionally be powered by PoE, so you can drop it into a distant segment of the Ethernet network without even supplying a separate power supply).
UPD : about the cons specifically Orange Pi 2G-IOT there is a separate article id_potassium_chloride . Be on the alert!
Banana pi m3
Together with Orange, Banana developed by the Chinese company SinoVoip is another “fruit” branch that has grown well since the advent of Raspberry. Following in the Raspberry wake, Banana consistently released the Banana Pi M1, M1 Plus, M2 Plus, M2 Ultra, M2 Zero, M3 models.
The current flagship Banana Pi M3 is based on the eight-core Allwinner A83T SoC (ARM Cortex-A7 processors, PowerVR SGX544MP1 graphics processor), clocked up to 1.8 GHz and working in an environment of 2 GB of RAM and 8 GB of flash memory. In addition to gigabit Ethernet, two USB, Wi-Fi 802.11 b / g / n, Bluetooth 4.0 and HDMI, there is SATA on the board. Like the Orange Pi Prime, the M3 has an IR receiver, CSI video interface, debug UART, microphone, line-out, and HDMI audio output. Unlike Orange, Banana has a MIPI DSI display interface combined with I2C for the touch screen. Naturally, there is a forty-contact GPIO comb.
Rock64
The Rock64 single-board computer is already equipped with 4 GB of RAM, serving the 64-bit ARM Cortex A53, the video subsystem is able to cope with 4K stream at a frequency of 60 fps. The device is powered by POE. The graphics subsystem ARM Mali 450MP2 corresponds to OpenGL ES 2.0, OpenVG1.1. Debian, Cent OS, Fedora, and Android 8 were ported to Rock64; in general, it should be noted that the developers and enthusiasts of this computer ported a large number of Linux-based OSes to it. Rock64 has abundant, detailed documentation and a lively, active community, so, taking into account good hardware specifications and sparing prices, this single-board is a good candidate for replacing the Raspberry Pi 3 in projects with increased hardware requirements.
Rock64 developers generously poured 64 GPIO pins, outputting Ethernet signals to them, so if you plan to control branched external peripherals on a single-board, take a closer look at this computer. In addition, there is USB3.0.
Rock64 has an older brother, ROCKPro64 , built on the eight-core 64-bit Rockchip RK3399 (four ARM Cortex A53 plus two ARM Cortex A72), with 4 GB LPDDR4 and two USB 3.0. PINE64, a producer of Rock64 and ROCKPro64, is generally a worthy example of a DIY business. The guys go the way, beaten by pioneers like Sparkfun or Adafruit, who have shown that you can supply your development with a complete set of design documentation and at the same time be a commercially profitable enterprise.
ASUS Tinker board S
Tinker is built on the basis of SoC Rockchip RK3288 with a quad-core ARM Cortex-A17 processor and runs on TinkerOS based on Debian, you can install Android. The Mali-T760 MP4 video processor supports OpenGL ES 3.1, OpenCL 1.1, Renderscript, and Direct3D 11.1.
The GPIO comb got a color coding, so when connecting external devices it will be a little more difficult to make a mistake. A small passive radiator glued to the processor case, which is purchased separately from competing boards, is already carefully included in the standard kit.
The Asus Tinker board S had a younger brother, the Asus Tinker board without on- board flash memory, but it did not have much success and has now practically disappeared from the market.
Libre Computer Renegade and Renegade Elite
Renegade, or the Libre Computer ROC-Rk3328-CC Renegade, is designed to be as similar to Raspberry as possible; for example, you can place the ROC-Rk3328-CC directly in the case purchased for Malinka.
SoC RK-3328 is built on the basis of a quad 64-bit ARM Cortex-A53 processor with an operating frequency of up to 1.5 GHz. SoC is the same as in Rock64, so here you also have the same Mali 450MP2 GPU with an operating frequency of 500 MHz. When ordering, you have the opportunity to vary the amount of RAM, you can choose 1 GB DDR4 (then the computer will cost you $ 35), 2 GB for $ 50 or 4 GB for $ 80. Of the operating systems, Ubuntu 18.04, Debian 9, OpenMediaVault 4, Station OS, and Android 7.1 are currently available.
Like the Asus Tinker board (without the S index), Renegade does not have on-board flash memory, you will have to use a microSD card slot or eMMC interface.
Libre Computer is one of the manufacturers that has shown good growth in the new business niche created with the advent of the Raspberry Pi. In addition to Renegade, in the summer of 2018 Libre Computer began production of Renegade Elite , a single-board computer Libre Computer ROC-Rk3328-CC Renegade Elite based on SoC Rockchip RK3399 with a six-core processor (two ARM Cortex-A72 cores and four ARM Cortex-A53) and GPU ARM Mali- T860 MP4, which has two USB 3.0 Type-C ports, a 60-pin PCIe slot, 128 MB on-board memory and a 60-pin GPIO comb. Renegade Elite has optional PoE support and can run Linux 4.19 or Android 8.
Odroid h2
Given its relatively low price, the Odroid H2, built on the basis of 64-bit 4-core Intel Celeron Gemini Lake J4105, may well qualify for a piece of the market niche occupied by single-board computers based on ARM processors. If you prefer x86-compatible solutions, this small motherboard with a size of 110 × 110 mm, with passive cooling, Intel UHD Graphics 600 GPU, PCI-E gen2 bus and dual SATA 6 GB / s will be to your liking.
According to the Intel specification, the maximum RAM size is 8 GB (SO-DIMM DDR4 2400 MHz, not included, purchased separately, as for any "pisyuk"), but the manufacturer Odroid H2 claims to have stuck two 16 GB strips (total 32 GB) and everything worked perfectly. Of course, the board supports Windows 10 / Linux x64, DirectX 12, OpenGL 4.3, OGL ES 3.0, OpenCL 2.0.
As an alternative to Odroid H2, you can consider UDOO X86 (there are options on Intel Pentium N3710 2.56 GHz and Intel Celeron N3160 2.24 GHz).
Arduino Mega 2560
You do not need to be Dr. Xavier from the People X franchise in order to hear the mental exclamations of some readers right now: “Why what ...! Where is Malinka and where is Arduinka? It’s the same as comparing a cheetah with E. coli! ” Yes, yes, that's right, Raspberry Pi and Arduino are in significantly different market niches, but if you look at the summary tables at the end of the article, you will find one point that makes two of these very diverse developments related. And this item is the price. Yes, they are asking for $ 31 for the Arduino Mega 2560 Rev3, and $ 42 for the Arduino Uno WiFi Rev2 (as the quickest readers have guessed, the board is equipped with Wi-Fi).
Let's take a look at the hardware stuffing of this “single board computer” (or do you need to omit the quotation marks?). 8-bit microcontroller ATmega2560 with a clock frequency of 16 MHz, 256 kbytes of flash memory (of which 8 kbytes are occupied by the bootloader), 8 kbytes of RAM and 4 kbytes of non-volatile memory. Of the communication capabilities, instead of the usual single-board computers Ethernet, Wi-Fi and Bluetooth, which are familiar from the previous compared models, in the case of the Arduino Mega 2560 we will have to mention four UARTs, one of which is connected to the built-in USB-UART converter. The converter itself, by the way, is also implemented on the AVR microcontroller, ATmega8U2-MU, but this is not important, there are options with specialized FTDI chips. Generally, the board’s characteristics (like a permissible current of 20 mA per output or the ability to configure 15 GPIOs as PWM outputs) predictably repeat the characteristics of the microcontroller on which it is built. The manufacturer himself positions Arduino Mega as a good basis for hobby projects related to 3D printing and robotics.
The Arduino world has its own analogue of the Raspberry Pi Zero microcomputer, this is the Arduino Nano board . Built on the basis of the ATmega328P microcontroller, with a size of 18 × 45 mm, the device boasts 2 kilobytes of RAM and 32 kilobytes of flash memory, 16 MHz clock and 22 GPIO pins, 6 of which can work as PWM outputs.
In general, the Arduino series is quite simple in terms of its hardware device, so even when I was in a hobbial-melancholic state of mind, I sat down and drew (with the help of Altium Designer) my version of Arduino Nano. Improved noise immunity by incorporating the USBLC6-4SC6 protective assembly into the USB circuit, finalizing the USB-UART converter in accordance with the AN-146 USB Hardware Design Guidelines for FTDI ICs and minor modifications to the circuit in accordance with AVR042: AVR Hardware Design Considerations. Added a gamma radiation sensor on PIN diodes ("Why? Because I can!"). So that the relatively high-voltage power supply of the radiation sensor did not have to be dragged from the outside, a small voltage multiplier was added, controlled by a microcontroller. Description of the resulting board is here., and the full project archive (with all Altium sources and libraries) you can download here . In general, of course, it’s a little strange that Arduino did not die out after the heyday of Raspberry and its clones. I think that the popularity of Arduino is not least due to what happened in the early to mid 2000s “shot” of the AVR architecture, developed by Atmel. Not to say that the market for 8-bit microcontrollers was empty, there was a pretty good choice between i51 and PIC, and 16-bit MSP430 was available for energy-saving solutions.
But the microcontrollers of the AVR series, combining the new successful RISC architecture, executing instructions in 1 clock cycle (which was undoubtedly a blow under the breath of the then i51, executing instructions in 12 clock cycles) and just in time for the cheaper internal flash memory, were a supernova. even against the background of not weak old-timers. As I remember now, with what pleasure I repeatedly flashed a flash AVR microcontroller; There was no JTAG in it, and it was impossible to look at the registers directly during operation, but compared to the pair of H1830BE51 + EPROMs with ultraviolet erasure, it was just a new future.
Maybe it's the Arduino IDE, which facilitates software development, or the friendly community of Arduino-compatible developers. In any case, Raspberry supporters have something to think about. Maybe the development threshold for modern A series ARM processors is too high, and therefore many developers, especially hobbies, are not ready to spend so much time mastering all the tricks of working with modern processors. Let's hope that something like STM32CubeMX appears (software for STM32 microcontrollers of the ARM Cortex-M0 ... Cortex-M4 series, which greatly simplifies the initial setup of the controller) and electronics lovers are also slowly migrating to the Raspberry camp.
I will not bore the reader with a further listing of all possible alternatives to the Raspberry Pi. I think you understand the main thing - there are alternatives, and options for a variety of hardware configurations and price categories are available to order: from boards with a price tag of up to $ 50 and hardware stuffing, very similar to the original Raspberry to more expensive devices, the price of which is gradually increasing in parallel with growth hardware capabilities.
In pursuit of the considered single-board computers casually, in a telegraph style, I will also mention such developments as Odroid-C2 ($ 59); Odroid-XU4 ($ 80, you can add the OGST Gaming Console Case for Odroid XU4 for $ 25) Pine A64-LTS ($ 32); NanoPi NEO4 ($ 45); Cubieboard4 CC-A80with PowerVR G6230 GPU ($ 130); Nvidia Jetson Nano on the quad-core Tegra X1 ($ 140); BeagleBoard X15 with two Ethernet ports and a combination of PowerVR GPUs with 4 GB of RAM ($ 263); LattePanda Alpha on Intel Atom X5-Z8350 ($ 240); Hikey 960 on an eight-core Kirin 960 with four ARM Cortex A73 cores clocked up to 2.3 GHz and four ARM Cortex A53 cores up to 1.8 GHz ($ 268) and BBC micro: bit as a possible replacement for Arduino ($ 15).
Summary table, main parameters
| Model | SoC | CPU | Graphics | Kernels | Frequency | The size | Price |
|---|---|---|---|---|---|---|---|
| Raspberry Pi 3B + | Broadcom BCM2837B0 | ARM Cortex A53 | Broadcom VideoCore IV | 4 | 1.4 GHz | 85.6 × 56.5 mm | $ 35 |
| Raspberry pi zero | Broadcom BCM2835 | ARM1176JZF-S | Broadcom VideoCore IV | 1 | 1.0 GHz | 65 × 30 mm | $ 5 |
| Raspberry Pi Zero W | Broadcom BCM2835 | ARM1176JZF-S | Broadcom VideoCore IV | 1 | 1.0 GHz | 65 × 30 mm | $ 10 |
| Banana pi m3 | Allwinner A83T | ARM Cortex-A7 | PowerVR 544MP1 | 8 | 1.8 GHz | 92 × 60 mm | $ 68 |
| Banana Pi M2 Zero | Allwinner H2 | ARM Cortex-A7 | Mali400 mp2 | 4 | 1.0 GHz | 60 × 30 mm | $ 18 |
| Rock64 | Rockchip RK3328 | ARM Cortex A53 | Mali 450mp2 | 4 | 1.5 GHz | 56 × 85 mm | $ 45 |
| Asus Tinker board S | Rockchip RK3288 | ARM Cortex-A17 | Mali T760 MP4 | 4 | 1.8 GHz | 54 × 86 mm | $ 92 |
| Libre computer racegade | Rockchip RK-3328 | ARM Cortex-A53 | Mali 450mp2 | 4 | 1.5 GHz | 85 × 56 mm | $ 80 |
| Libre Computer Renegade Elite | Rockchip RK3399 | ARM Cortex-A72 + Cortex-A53 | Mali-t860 | 6 | 2.0 GHz | 120 × 72 mm | $ 100 |
| Odroid h2 | - | Intel Celeron J4105 | Intel UHD Graphics 600 | 4 | 2.3 GHz | 110 × 110 mm | $ 111 |
| Arduino mega | - | ATmega2560 | - | 1 | 16 MHz | 53 × 102 mm | $ 31 |
Summary table, memory and interfaces
| Model | RAM | Flash | GPIO | USB | Ethernet | Wifi | Bluetooth |
|---|---|---|---|---|---|---|---|
| Raspberry Pi 3B + | 1 GB | MicroSDHC slot | 40 | 4 | 1000 Mbps | 802.11 b / g / n / ac 2.4 / 5 GHz | 4.2 LS BLE |
| Raspberry pi zero | 512 MB | MicroSDHC slot | 40 | 1 | - | - | - |
| Raspberry Pi Zero W | 512 MB | MicroSDHC slot | 40 | 1 | - | 802.11 b / g / n | 4.1 BLE |
| Banana pi m3 | 2 GB LPDDR3 | 8 GB eMMC | 40 | 3 (2 × 2.0, 1 × OTG) | 1000 Mbps | 802.11 b / g / n | 4 |
| Banana Pi M2 Zero | 512 MB DDR3 | MicroSDHC slot | 40 | 1 × USB 2.0 OTG | - | 802.11 n | 4 |
| Rock64 | 4 GB LPDDR3 | 128 MB | 64 | 3 (3.0, 2.0, OTG) | 1000 Mbps | 802.11 b / g / n | 4 |
| Asus Tinker board S | 2 GB LPDDR3 | 16 GB eMMC | 40 | 4 × USB 2.0 | 1000 Mbps | 802.11 b / g / n | 4 |
| Libre computer racegade | 4 GB DDR4 | - | 40 | 3 (1 × 3.0, 1 × 2.0) | 1000 Mbps | - | - |
| Libre Computer Renegade Elite | 4 GB DDR4 | 128 MB | 60 | 5 (2 × 3.0, 3 × 2.0) | 1000 Mbps | - | - |
| Odroid h2 | 2 DDR4 SO-DIMM slots | 128 MB (BIOS) eMMC slot | - | 4 (2 × 3.0, 2 × 2.0) | 2 × 1000 Mbps | - | - |
| Arduino mega | 8 kb | 256 kB | 54 | USB-UART Converter | - | - | - |
In recent years, a lot of interesting things have been happening on the single-board computer market. New models are constantly appearing and disappearing in all niches, starting from Arduino, affecting Raspberry and ending with motherboards compatible with 8th generation Intel processors. For example, right now on Kickstarter there is a campaign of UP Xtreme, an Intel-compatible motherboard, and the development of the promising Galileo platform, on the contrary, has been scaled down. The developers of Renegade Elite, by the way, also raised funds to launch production through the Indiegogo crowdfunding platform. So if you want to keep abreast of the latest developments in the field of single-payers, sometimes go over the sections “Technology” of crowdfunding sites.