Somebody asked what was the cheapest MCU available on Google+, so I thought it would be fun to find the cheapest one regardless of specifications. It turns out there an older thread with this very question on StackExchange, and at the time (2011) Microchip PIC10F200 8-bit MCU with 256B RAM in SOP-23 package was the cheapest one among the answer, and somehow the price has not changed as it’s still $0.32 per unit for 1k orders.
Not bad price, but back in the days when I wrote on CD and DVD players, we had some price pressure from customers, so we looked for a cheaper a microcontroller, and ended up using Holtek because of the competitive pricing. We suffered a bit during development due to incomplete documentation, but eventually did the job. Anyway, I went to Holtek website found a “cost effective I/O MCU” category, and HT48R002 appears to be the lower end. I checked the price on 1688.com, and several sellers offer it for as low as 0.56 RMB for 1k orders, which converts to about $0.085 per MCU.
Let’s look what we get for that outrageous price:
- 8-bit RISC MCU @ 8MHz
- 1K x 14-bit ROM (OTP)
- 64 x 8-bit RAM data memory
- 6x I/O including 1x external interrupt pin, and 1x 8-bit timer
- Two oscillators – Internal high speed RC: HIRC; Internal low speed RC: LIRC
- Low voltage reset function
- Operating Voltage – 2.3 to 5.5V
- Package – 8-pin DIP/SOP
Since this MCU has an OTP (One Time Programming) memory, you’d need an ICE (In-Circuit Emulator) to develop for the micro-controller in assembly, and once you’ve debugged your code, which should not be too complex considering the available RAM and storage, you’d have the factory burn the firmware to the device before or during mass-production. More details including the instruction set can be found in the datasheet.
Do you have other candidates to claim the “cheapest MCU” crown?