Comment by the__alchemist | Hacker News Reader

Comment by the__alchemist | Hacker News Reader

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It's a family of microcontrollers by Espressif. A microcontroller (MCU) is a type of integrated circuit (IC: physical appearance: Black rectangle of epoxy with exposed metal tabs). It has, in the same IC, a CPU, RAM, non-volatile FLASH memory, and a collection of peripherals which vary depending on the MCU. These usually include I/O protocols, ADCs, DACs, DMA controllers, math processors etc.

Stated another way: An MCU, like the ESP32, is a tiny computer, sans the hardware you physically interface with it.

The computing power, and memory is much lower than your desktop or laptop PC (or mobile phone), but if you are using it to run a dedicated task, instead of using a big OS like Linux or Windows, it can complete the tasks really fast (often microseconds) and with minimal power use. This is because it's easy to program to do exactly what you need, with nothing competing for the hardware.

A note on ESP in particular compared to other MCUs: It's one of the only (Or was?) options which has Wi-Fi integrated into the MCU itself. It's a good default if you want that.

> I's one of the only (Or was?) options which has Wi-Fi integrated into the MCU itself. It's a good default if you want that.

Indeed. The closest direct competitor is likely the Nordic nRF52840, which does bluetooth + thread, but can't talk actual wifi

The closest direct competitor is Bouffalo Lab's BL6xx chips, which do bluetooth and wifi and have an open SDK. Their documentation is very poor unfortunately (at least in English).

Otherwise NXP recently released their RW6xx line with wifi/bt/thread/zigbee. But as with any other western maker, the documentation and SDK aren't as easily accessible to mere mortals (but I think NXP in particular has gotten better with this).

There are a lot of competitors, in fact, in term of value the ESP32 is really bad.

The only thing Espressif does good is SDK support.

That’s crazy to me: they already have to go through certification for the 2.4GHz stuff, why not include a lower wifi standard in there (for the 2.4GHz band)…

It's probably for power reasons, the nrf series are really great on power consumption.

Yeah, if you look at a flagship nRF52840 board like the Xiao Seed, it ships with an integrated lithium charge controller, and just 5 μA power draw in deep sleep. If you are building any small battery-operated device, it's a no-brainer

I had to choose between an ESP-based and nRF-based MCU for my MeshCore node, the power consumption between the two made it obvious the nRF one was the way to go for a solar-powered repeater.

I’d say as well, that a huge difference is a microcontroller has direct access memory (I.e. without translation), and a bigger computers CPU/SoC has an MMU (memory management unit) that does address translation. This is a key hardware difference for isolation of multiple processes, which you don’t typically have in a microcontroller (you _could_ have an MPU to give you some partitioning, but that’s further down the road).

Lots of microcontrollers have MMUs, such as some Esp32, some microchip flavors, some stms, nxp, ti siara, renesas and Infineon flavors.

So I wouldn’t claim this is a hard and fast rule. Lots of mcu lines have added mmus on some variants.

The article literally has a section heading

> Espressif put a real MMU in the ESP32-S31

I think their point was more: is an ESP32 more like a arduino (or any other MCU) running bare metal or some thine RTOS or more like a raspberry pi which is more like a mini computer running a full fledged Linux. And I guess the answer it kind of always sat in between a little bit and now the family kind of spreads out across this whole spectrum.

> is an ESP32 more like a arduino (or any other MCU) running bare metal or some thine RTOS or more like a raspberry pi which is more like a mini computer running a full fledged Linux

Espressif's answer: yes

Arduino have muddied this water now, too, as some newer ones come with a full fledged Qualcomm SOC, multiple GB of RAM, and power consumption which requires quite a beefy heatsink.

To date ESP32s have been best thought of as arduino-like things, albeit with some fancy hardware available like WiFi and Bluetooth stacks. But very much microcontroller boards where you compile firmware and push it to the board over USB.

You can actually do an awful lot of stuff with an ESP32, which often comes as a surprise to people who think you need a full Linux system just to turn a light on and off. For example Goodwe solar inverters/controllers are controlled by ESP32s and do a great job while Enphase controllers use Linux SBCs and are flaky, bug-riddled garbage.

People still have no idea that ESP32 is much better than most MS-DOS PCs we had at the time, no need for Linux.

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