They are huge step ahead: the upcoming CH32H417 has pretty much all PHYs integrated (!). For 10/100M Ethernet, USB-C 5GBbps and USB HS 480Mbps. That dramatically reduces the components needed to get that stuff running.
I also build a small robot with the ultra cheap CH32V003. That's a full fledged 48MHz microcontroller with 16kb flash and 2kb SRAM. Fun little thing.
If you are used to the ST HAL you will be able to work with them within 10 minutes. Their API style is similar.
links from 02025-03-16:
https://www.lcsc.com/product-detail/Microcontrollers-MCU-MPU... #LCSC #pricing for 16-pin #CH32V003 #microcontrollers #electronics #hardware: 14.21¢ in quantity 500. Not the cheapest, but it’s a RISC-V with IIRC an on-board op-amp, though the linked datasheet only covers the CPU really.
https://www.lcsc.com/product-detail/Microcontrollers-MCU-MPU... #LCSC #pricing for 14-pin #PY32 #ARM #microcontrollers #hardware, 9.01¢ in quantity 500. Not the cheapest, but it’s an ARM. #electronics
links from 02025-02-08:
https://www.lcsc.com/datasheet/lcsc_datasheet_2410121502_PAD... #PDF English #datasheet for #Padauk PFS122 #microcontrollers which have a 12-bit ADC and 24MHz. Not quite the cheapest microcontroller but they only cost 4.32¢ in quantity 2000.
links from 02024-08-01:
https://www.lcsc.com/product-detail/Microcontrollers-MCU-MPU... new cheapest #microcontrollers: Cypress CY8C4045FNI-DS400T, 1.5¢ in quantity 1000. It purports to be a 48MHz Cortex-M0 ARM with 32KiB of Flash and 4KiB of SRAM in a 1.6mm x 2mm package, 0.31-0.37 mm thick, with nine GPIO pins. I think that’s 4000 Dhrystone MIPS per dollar. #electronics #hardware #pricing
links from 02024-05-12:
https://jlcpcb.com/partdetail/NyquestTech-NY8A051H/C5143390 #JLCPCB has new cheapest #microcontrollers: #Nyquest NY8A051H: 1.58¢ each in quantity 20000, or 3.2¢ in quantity 1 #hardware #pricing
links from 02023-10-12:
https://www.lcsc.com/product-detail/Microcontroller-Units-MC... #Padauk PMC251 is one of their cheapest multithreaded parts; LCSC lists it here at US$0.1071 in quantity 500, which works out to US$53.55. 1 kiloword instruction memory
As of today (02025-10-15), the CH32V003A4M6, the PY32F002BD15S6TU, the PFS122, and the PMC251-S14 are in stock. The CY8C4045FNI-DS400T, the CY8C4013SXI-400, and the NY8A051H (not an 8051 despite the name) are out of stock. Today what I see are:
https://www.lcsc.com/product-detail/C49173938.html Currently cheapest #microcontrollers #pricing on LCSC: PMS150G-U06 (a SOT-23-6) for 2.02¢ in quantity 3000. #Padauk has broken the 3¢ barrier! One-time programmable. #electronics #hardware
https://www.lcsc.com/product-detail/C2857167.html Almost cheapest #microcontrollers #pricing on LCSC: NY8A054ES8, a SOP-8, for 3.91¢ in quantity 1000. This is from JSMSEMI (Shenzhen JSMicro Semiconductor Co., Ltd.) 1T 8-bit 8MHz chip, 128 bytes RAM, 2k × 14-bit EPROM program memory (but no quartz window, so one-time programmable). 8-level hardware stack. The datasheet is full of descriptions of peripheral registers and pin circuit schematics, and then the 55-instruction instruction set is documented on pp. 76–91.
Cheapest "general purpose" microcontrollers that have enough features for good developer experience are Puya and WCH.
If you are a seasoned STM32 developer you will get used to them within a day.
Examples:
https://download.py32.org/Datasheet/en/PY32F071_Datasheet_Re...
https://arvidtek.com/wp-content/uploads/2025/06/CH32V006DS0-...