Programming the Open-V Open Source CPU on the Web

openriscv_webYou can now program the Open-V on the web, and see the results in real time. The code is compiled in the web IDE and then flashed to a microcontroller which is connected to a live YouTube live stream. It’s pretty neat to flash firmware on a microcontroller thousands of miles away and see the development board blink in response.

We’ve covered the Open-V before, and the crowd funding campaign they have going. The Open-V is an open hardware implementation of the RISC-V standard. And is designed to offer Cortex M0-class capabilities.

This feels like a create way to play around with some real hardware and get a taste of what a future where we can expect Arduino-like boards, open source down to the transistor level.

For a closer look at why open silicon matters, check out [Brian Benchoff’s] hands-on review of the HiFive, an Arduino form-factor board built around an open hardware RISC-V microcontroller.

Open-V, The First Open Source RISC-V Microcontroller

Open Source software has been around for decades. Over these decades, Open Source software has been the driving force behind most of the Internet, and all of the top-500 supercomputers. The product of the Open Source software movement is perhaps more important than Gutenberg’s press. But hardware has not yet fully embraced this super-charging effect of openness. Being able to simply buy an open source CPU, free of all proprietary bits and NDAs is impossible.

Now, this is finally changing. OnChip, a startup from a group of doctoral students at the Universidad Industrial de Santander in Colombia, have been working on mRISC-V, an open 32-bit microcontroller based on the RISC-V instruction set. It’s now a crowdfunding campaign, and yes, you can simply buy an open source chip.

We’ve taken a look at onchip’s Open microcontroller project before. The team has made significant progress of moving from something that can run on an FPGA to the tapeout of a real, physical chip. The onchip twitter timeline is a flurry of activity, with real silicon and a prediction that 50% of low-end microcontrollers will be running RISC-V in a decade.

A render of the Open-V dev board

If you want to get your hands on one of these open microcontrollers, the Crowd Supply campaign is actually fairly reasonable, considering this is custom silicon. $49 USD gets you a first-run mRISC-V in a QFN-32 package. $99 gets you the mRISC-V dev board with an SD card slot, USB, regulators, and of course the micro itself.

This chip’s capabilities are almost on par with a low-power ARM Cortex M0. The chip itself runs at 160MHz, has SPI, I2C, SDIO, and JTAG, as well as a 10-bit 10MS/s ADC and a 12-bit DAC. There are 16 GPIO pins on mRISC-V. You won’t be able to build a smartphone or laptop with this chip, but you will be able to build an Internet of Things gizmo.

While OnChip’s efforts won’t result in a completely open source smartphone, there are other projects in the works that will bring an Open Source core to more powerful devices. lowRISC is a project to bring a Linux-capable System on Chip to production, and various people smarter than us have brought GCC, LLVM, and QEMU to the architecture.

Most of the efforts to bring the RISC-V architecture, and indeed most Open Source processors, have focused on the big chips — full CPUs and SoCs. Onchip’s mRISC-V goes the other direction to create a small, open microcontroller. If you’re looking to create an ecosystem of Open processors, this makes a lot of sense; there are more Honda Civics on the road than Lamborghinis, and Microchip and TI ship far more microcontrollers every year than Intel ships CPUs.