Embedded techniques engineer Jay Carlson has been on the hunt for the lowest-possible-cost microcontroller to function onboard flash storage — and believes he is discovered it, within the type of a Puya chip that includes an Arm Cortex-M0+ core.

“Puya? They’re a flash reminiscence firm out of Shanghai that’s been round since 2012 — largely making actually low-cost SPI flash reminiscence for IoT [Internet of Things] devices,” Carlson explains in a weblog publish delivered to our consideration by Adafruit. “Whereas it could appear odd that the most cost effective MCU [Microcontroller Unit] is made by a flash reminiscence firm, if you realize a factor or two about chip design (which I do not) you may know that it’s usually the flash reminiscence contained in the half that is the costliest IP within the design.”

It is this, Carlson explains, which causes many ultra-low-cost microcontrollers to be constructed with out onboard flash in any respect, providing as an alternative single-use electronically programmable read-only reminiscence (EPROM) that may solely be burned as soon as earlier than having its contents locked eternally extra. The Puya PY32 vary, against this, comes with true embedded flash — and a well-known Arm Cortex-M0+ core, moderately than the free and open-source RISC-V structure seen in lots of its low-cost rivals.

“On the time of publication, costs have shot up fairly a bit in comparison with once I first ordered these elements,” Carlson notes, “however at present, the costs vary from lower than 8 cents as much as $0.74 relying on the precise half, configuration, and amount you’re shopping for. The F002A is the bottom mannequin: it clocks in at 24MHz, has 20k of flash, [and] 3k of SRAM [static RAM].

“It has one advanced-control timer with 4 outputs (plus two complementary pairs for driving H-bridges), 1 low-power timer, 1 general-purpose timer, a 1 MSPS 12-bit ADC with 6 exterior channels, two comparators, a fundamental watchdog timer, and one SPI, I2C, and USART peripheral. And since this can be a Cortex-M0+, you get an SWD debugging interface, a SysTick timer, and a nested vector interrupt controller (NVIC) bundled in.”

That is a variety of options in a sub-10¢ chip, however there’s extra to suggest the elements than simply value. Carlson describes the event expertise as comparatively easy, bar somewhat fiddling to get the software program improvement package configured for Visible Studio Code moderately than Kiel MDK. “General, these elements are a lot simpler to make use of than different elements on this value vary,” Carlson says, “which frequently have poor English documentation, no code samples or peripheral libraries, or require vendor-provided IDEs and peculiar tooling.

“Backside line: the Puya PY32 ecosystem is simply plain boring — and that’s factor.”

Carlson’s full write-up is offered on his web site; he has additionally revealed a pattern mission on GitHub to function a quick-start for others adopting the identical chips.