[Cheer2171]

I'll plug ESP32 more broadly, which are half the cost of the Adafruit user friendly chip, which is only single core. If you're familiar with Arduino, the regular dual core ESP32 are fully compatible with cross-platform Arduino C code. You can get ESP32 for $5 each from US resellers or even cheaper in bulk on Aliexpress from China.

If you really need to get cheap, the ESP8266 is also fully Arduino compatible and less than $2. Still way overpowered for a wireless temperature sensor sending packets to homeassistant or whatever.

[sitkack]

If it solves your problem for a price that is acceptable, it isn't "overpowered". This isn't using an i5 to blink an LED territory.

Unless you are shaving pennies for mass production, I'd stay away from any of the Tensilica LX6 LX7 based ESP32 parts. Toolchain and library support will be much better with the RISC-V based parts.

The ESP8685 is the current budget RISC-V based MCU. 384K of user SRAM, 4MB of Flash, 160Mhz RISC-V core. $1.50 qty 1.

https://www.espressif.com/sites/default/files/documentation/...

[gsliepen]

Are the toolchains and libraries already much better or will that be in the future? Note that the CPU architecture is the least important thing of a microcontroller; as long as you have a decent compiler for a higher level language you don't care what instruction set it uses. And I can see the toolchain getting more love if it's a more widely used CPU architectue (and Tensilica is rather niche), but I don't see why library support would be any better.

[sitkack]

The LX6 wasn't supported by LLVM for the longest time, only GCC.

RISC-V is nearly identical to MIPS or Arm, so anything to add Arm support to library, would also make it RV compatible (before inline asm).

Build breakages on LX6 or LX7 are 100% on you.

[sitkack]

Forgot to mention, that as these MCU and crossover parts get more capable, the expectation that you can basically run a linux distro and then also communicate with many RT control-loop mcus. At some point, embedded control applications will have a Js toplevel.

[Cheer2171]

I have an open source fetish for RISC-V, but to be honest, the LX6 and LX7 toolchains are perfectly fine in terms of functionality for what most people need a low-cost chip to do. ESP-IDF and FreeRTOS are pretty mature at this point. Really cool things could happen with RISC-V. But when I need a chip to read/write some GPIO pins, drive a display, and do some networking, it doesn't really matter.

[hi-v-rocknroll]

I think I bought about 5 ESP32-WROOM-32D, 25 ESP8266, 10 Arduino Mini clones, 10 Arduino Nano clones during the pandemic. They're coming out of my ears.