The SparkFun RED-V (pronounced “red-five”) RedBoard is a low-cost, development board featuring the Freedom E310 SoC which brings with it the RISC-V instruction set architecture (ISA). What sets the RED-V RedBoard apart from the rest is the completely open-source approach from hardware to ISA. That means anyone can make full use the microcontroller without requiring royalties, licenses, or non-disclosure agreements.
The RED-V RedBoard comes in the familiar Arduino Uno R3 form factor and includes the SiFive Freedom E310 core, 32MB of QSPI flash, an NXP K22 ARM Cortex-M4 for USB connectivity and operating as a JTAG interface, and a Qwiic connector to make future I2C offerings easy*. The modern USB-C connector makes it easy to program and for more advanced users who prefer to use the power and speed of professional tools, we've also exposed the JTAG connector. Additionally, it comes programmed with a simple bootloader making the RED-V the best way to start prototyping and developing your RISC‑V applications.
The on board Freedom E310 (FE310) is the first member of the Freedom Everywhere family of customizable SoCs from SiFive. Designed for microcontroller, embedded, IoT, and wearable applications, the FE310 features SiFive’s E31 CPU Coreplex, a high-performance, 32-bit RV32IMAC core. Capable of running at 150MHz, the FE310 is among the fastest microcontrollers in the market. Additional features include a 16KB L1 Instruction Cache, a 16KB Data SRAM scratchpad, hardware multiply/divide, a debug module, flexible clock generation with on-chip oscillators and PLLs, and a wide variety of peripherals including UARTs, QSPI, PWMs, and timers. Multiple power domains and a low-power standby mode ensure a wide variety of applications can benefit from the FE310. The RED-V requires Freedom Studio software or a Zephyr RTOS build environment set up to program the board and interface with it.
Note: Please be aware that Qwiic Libraries are not yet available for the Freedom Studio SDK or the Zephyr environment that runs on the FE310. We will update the community when these become available.
If a board needs code or communicates somehow, you're going to need to know how to program or interface with it. The programming skill is all about communication and code.
Skill Level: Expert - You should be extremely comfortable programming on various hardware in several languages.
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If it requires power, you need to know how much, what all the pins do, and how to hook it up. You may need to reference datasheets, schematics, and know the ins and outs of electronics.
Skill Level: Rookie - You may be required to know a bit more about the component, such as orientation, or how to hook it up, in addition to power requirements. You will need to understand polarized components.
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Based on 6 ratings:
Amazing to have ready access to a sifive 32-bit chip. I am just getting started with risc-v, and this is a great learning platform.
This is not a replacement for ARM or AVR micros... library support is still very limited. But it supports the tool chain and thus provides access to the ISA.
Go for it. At this price it’s a no brainer. I recommend Anthony J Dos Reis’s book on risc-v assembly as a companion to the board.
The RED-V features a SiFive FE310 and a Segger JTAG interface. I downloaded the turnkey IDE from SiFive and was running "hello world" in a matter of minutes. If you are an early purchaser, your RED-V may have a wrong R8 value; SparkFun has provided an updated RED-V to correct this, as well as directions on how to re-work R8 on your first RED-V. The impact of incorrect R8 is the PLL clock will not run - but the board defaults to 16MHz crystal oscillator so this may not be a problem.
RED-V includes a 32.768kHz oscillator for the FE310 RTC which just works when enabled.
USB-C might be a little odd for some users but all you need is a cable if you don't already have one.
The FE310 is not a mixed-signal chip - it provides a good amount of I/O but if you need an ADC or DAC, you'll need to connect that via the expansion connectors.
This board has a SiFive FE310 chip. It's roughly equivalent to a Cortex-M3 chip. ie- 32-bit, no floating point (RV32acimu). I get the impression the FE310 chip is more of a demonstration chip than a serious attempt to take on other ARM microcontrollers. There are not that many peripherals on chip. It only has 16 KiB of on-chip RAM. Still - it's a good RV32 reference design and the onboard J-Link interface makes it easy to use. I bought it as a RISC-V learning platform, so I'm happy with it. If I wanted a RISC-V microcontroller for a product I'd probably be looking at a more featureful GigaDevice chip.
This board is very similar to the SifFive HiFive1 RevB, but with some nice quality of life improvements.
In particular I love the surface mount headers vs through hole. It makes the board much easier to throw around or leave on top of tables or laptops while I'm working with it. The substitution of USB-C for micro is a nice touch. I'll admit I was lacking in USB-C cables, but side-by-side with my other micro-b based boards the connector feels more sturdy and solid. The lack of ESP32 on here I consider a feature as well ;D Not only lowering the price but also decreasing weight and complexity of peripherals to use.
I have a handful of different FE310 based board lying around and I find this is my go to board when I'm just hacking on software or trying to work on the SDK itself.
In general, for the G002 based boards (HiFive1 RevB, and RED-V boards) there is currently as of writing no OpenOCD or Arduino support. Sparkfun does a good job not mentioning this and has a great guide for getting started using this board.
I am very disappointed by the lack of Sparkfun response to the USB Drivers for Jlink, and so I have thrown the risc-v board into the junk box.
The ""RED-V Development Guide" page" is out of date. The instructions to install USB drivers for win10/x64 no longer apply because the latest downloaded Freedom Studio no longer provides it. Freedom Studio does supply supply "instDrivers.exe", but that fails to open.
I report my problem to Sparkfun but no response. Later in July, 2 weeks ago, I post a help request in the related Sparkfun forum, but no response yet.
I buy a HiFive1RevB board and try that, and get the same problem. I also try all this again on a different computer, but no success.
I did discover an old 2015 Segger forum comment, that it is not their fault and blames windows. I thought this was going to be a fun project during my vacation time but it turned out to be frustrating misery.
The RED-V is a semi-clone of the SiFive HiFive1 RevB. The SiFive board has an ESP wifi / bluetooth device on board -- but as far as I can tell it isn't used for anything. It also has an RGB LED. This board has only a single blue LED and no ESP device. Otherwise they appear to be the same.
I was able to download Freedom Studio, install everything and get a demo going within an hour or so. The basic HiFive1 RevB code ran on the RED-V board without issue. Note that the LED count and location must be updated, but otherwise things worked really well. SiFive has done a lot to make Eclipse feel more like a dedicated embedded IDE.
The most difficult thing about the Freedom Studio install was the j-link driver installation. I did it by locating the j-link device in the Win10 device manager and updating the driver with the jlink drivers in the Freedom Studio.
The FE310 has the ability to run code from a QSPI. This is how the RED-V works. However, when it comes to RAM, it's a little limited at 16Kb.
For an intro-board for RISC-V, I'd say this is a great starting point.