EYE on NPI: Renesas RA4M1 Microcontroller Series

This week's EYE ON NPI is Big In Japan, it's the Renesas RA Microcontroller Series (https://www.digikey.com/en/product-highlight/r/renesas/ra-mcus) available at DigiKey in a wide range of sizes and configurations. With the chip shortage easing up, it's a great time to look at what chips to use for your next design. And while we have covered a ton of Arm Cortex microcontrollers on EYE ON NPI (https://blog.adafruit.com/?s=eye+on+npi+cortex), we haven't yet taken a look at Renesas' RA offerings. Renesas is a company created by the merging of the silicon design groups from Hitachi, NEC and Mitsubishi Electric (https://www.youtube.com/@RenesasPresents), so not surprisingly it's very Japanese-focused and used a lot in Japanese electronics companies but not as often in the USA. However, it's always good to have more competition and with the Arm Cortex standard, it's easy to move from one chip vendor to another without having to do a lot of re-targeting. So let's take a look! We saw Renesas highlighted over on DigiKey (https://www.digikey.com/en/product-highlight/r/renesas/ra-mcus) and the same day also received our new Early Access Arduino UNO R4 Minima (https://store.arduino.cc/pages/unor4) for us to use in making sure all our libraries work. The UNO R4 is the long-awaited upgrade to the popular R3 (https://www.digikey.com/en/products/detail/arduino/A000073/3476357) which came with an 8-bit, 16 MHz, 16 KB Flash, 2KB SRAM chip. While Arduino has come out with many other dev boards since then, the UNO hadn't got an update to 32-bit in a while. The challenge? Finding an affordable 32-bit chip with native USB, Cortex M3 or M4, good software SDK and 5V compatibility. That last part is the hardest, for example there's no ATSAM chip that has both USB and 5V compliance. An acquaintance just came back from a holiday in Japan and she mentioned that "everything is just...a little better there than here in the US!" and that's how we felt when looking at the RA4M1 datasheet (https://www.renesas.com/us/en/document/dst/renesas-ra4m1-group-datasheet) The RA4M1 series is a great pick for an 8-bit upgrade. The core is a Cortex M4 which means you're going to get good speedy computation with built in floating point and DSP instructions. For flash memory, 256 KB stores your code and there's a separate 8KB "EEPROM" like section. For RAM, 32 KB is available. It's got all the peripherals you expect such as timers, DMA, ADCs, USB full-speed, I2C, SPI, and UART as well as some upgrades you can't get on 8-bit chips. For example, the ADC is 14 bits, and there's also a 12-bit DAC. There's 4 internal op-amps and 8 total timers! There's two I2Cs, SPIs and UARTs and also CAN bus. A built in RTC is a true real time clock, with battery backup. There's also capacitive touch sensing and a segment LCD controller - our friend Joey Castillo will love that! (https://www.joeycastillo.com/objects/lcdwing/). In addition - we also saw some really beautiful silkscreen board designs for the Renesas Gadget Series (https://www.renesas.com/us/en/products/gadget-renesas) as well as an online code editor for compiling for the chip series. (https://www.renesas.com/us/en/products/gadget-renesas/boards/gr-sakura/project-sketch-on-web-compiler) We're hoping some of that work gets revitalized with the many makers folks who will be hacking with the R4. If you can't wait to try the Renesas RA4M1 (https://www.digikey.com/short/wt4b872q) chip out, Digikey has an affordable RA4M1 dev board in stock (https://www.digikey.com/short/3qzr0bbw) which comes with a J-Link on-board debugger with separate USB port, a few onboard peripherals, current sensing jumpers, and tons of GPIO so you can prototype your design quickly. Once you've got your design sorted out, chips are available for immediate shipment in TQFP (https://www.digikey.com/short/f3m2pffz) and QFN (https://www.digikey.com/short/fn2m9bbm). Order these from DigiKey and you will say "Konnichi wa" (https://en.wikipedia.org/wiki/Konnichiwa) to a new family of microcontrollers by tomorrow morning.