Comment by dheera | Hacker News Reader

Comment by dheera | Hacker News Reader

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Personally I really like the following boards for general projects:

- FeatherS2 (runs CircuitPython): https://unexpectedmaker.com/shop/feathers2-esp32-s2

- TinyPICO (runs MicroPython): https://www.tinypico.com/

They're both designed by the same dude. I'm not affiliated with them, I've just tried dozens of microcontroller boards and these two are easily the winners in my book for versatility in hobby projects.

These boards are absolutely jam-packed with features (capacitive touch sensing, RGB indicator LED, Li-Po battery management, ...) but moreover support Bluetooth and Wi-Fi. That's a major problem with the Pi Pico. You'll end up with a mess easily 2-3 times the physical size of the Pico to get Wi-Fi on it in the form of HAT-like boards, whereas the above microcontrollers have everything on-board.

By the way, CircuitPython is for the most part a real pleasure to use. If you slap an Adafruit display on them, with about 4 lines of code you can have the Python interpreter's STDOUT go straight to the display. The boards also emulate a USB drive that exposes all the Python code so you can program them with literally zero additional software.

I've only just got started in electronics, and I have to say I find the range of options to be bewildering - what do you think of the Adafruit Feather, Teensy, or Arduino Nano?

(I think they're all comparable products ... apologies if not)

Nope, these are all pretty comparable. And from the beginner point of view, they're all similar. They can all be programmed using the Arduino IDE and language, and all except the Nano can also be loaded up with Circuit Python and programmed in scripts rather than binary.

They're all pretty simple to use, with good documentation. I would probably add an M5StickC to this list, as they come as a nice modular package, with case and screen and a bunch of fun things for experimenting.

Since they can all be programmed using Arduino IDE, which has good documentation and forum support, you don't have to deal with a bunch of external toolchains and whatnot (though I would suggest VSCode with the PlatformIO plugin as soon as you're comfortable with the programming side of things.)

Ordered most to least simple: Nano Feather M5StickC Teensy

Ordered by most to least powerful: Teensy M5STICKC Feather Nano

Ordered by most to least peripherals: M5STICKC Teensy Feather Nano

Ordered by most to least reliable: Nano Teensy Feather M5STICKC

FYI there are already new Feather and Nano versions in the works that will have the RP2040 chip!

I haven't used all of these products. I have used several generations of Teensy for projects. I'm a big fan! They're powerful, well thought out, and inexpensive. Paul Stoffregen (creator of the Teensy products), is amazingly responsive to users. The only downsides (for some) is that you have to know C to program them. You can use the Arduino libraries if you want, which provides you with a lot of functionality with very little effort. If you have a specific project you'll be manufacturing, you won't want to use something like this. You'll want to design your own board that only has what you need. But for prototypes, small run, or one-off projects, it's hard to beat the power of a Teensy 4.

As stated elsewhere, all are great. If you just want to get going with CircuitPython on some hardware, I really recommend Adafruit’s CircuitPlayground series[1]. They have things like LEDs, temp sensor, speaker, mic, gyro, buttons, switches, and touch-capacitive pads all in a tiny form factor which means you don’t have to get into breadboarding, soldering, or wiring anything up to do an amazing variety of things and get your feet wet.

[1] https://www.adafruit.com/index.php?main_page=category&cPath=...

What do you think of Wemos D1 in comparison? They also seem to have onboard WiFi and Bluetooth, and support micropython.

I don't know too much about its battery management, though. The microusb port seems like a good thing?

I used a Wemos D1 ESP8266 in this project [0]. Plenty good for the project at hand. I heard they have an ESP32 version now?

For one-off personal projects I'd probably still reach for a TinyPICO or FeatherS2 though because of the additional features they have, and that they have a Discord server you can ask questions to, but if you're deploying a dozen of them in your garden and want to save money then yeah, the Wemos would probably be a good bet. Support and documentation is a little sparse though, in comparison.

[0] https://github.com/dheera/shadow-clock

A great thing about the ESP32 in my experience is the 5v out. 3.3v can often power things that claim to need 5v, but bad things happen, like reboots. Some claim to have had damage too, but that hadn’t been my experience.

The D1 Mini is my favorite ESP8266 board right now. It has built-in WiFi of course. It is physically smaller than a NodeMCU, but still exposes enough GPIO pins to allow interesting peripherals. The built-in micro-USB connector and USB-Serial chip means that programming it is easy, it doesn't need a separate programmer like the ESP-01. Unlike the ESP-01, the D1 Mini exposes the GPIO16 pin (aka D0) which is required to wake the board from DEEP SLEEP. The ESP-01 requires a soldering hack to enable DEEP SLEEP.

The LDO voltage regulator on the D1 Mini is so good that in DEEP SLEEP mode, it consumes only about 200 microamps, so I use it directly in battery-operated applications. In comparison, the ESP-01 goes down to 40 microamps in DEEP SLEEP, so the overhead of the voltage regulator is only about 160 microamps. (Edit: Both of those numbers include the DHT-22 temperature sensor).

My outdoor temperature sensor uses a D1 Mini with 3 x AA NiMH batteries feeding the voltage regulator, and it lasts 4 months. It wakes up for 5 seconds, every 15 minutes, reads the temperature and battery voltage, then transmits the info to an MQTT server. In theory, the ESP-01 (w/ soldering hack) would last 6 months on those batteries, but the difference isn't worth the extra hassle of an ESP-01 for me.

My biggest gripe about the NodeMCU honestly is that it's almost impossible to find one without the headers pre-soldered. The D1 Mini and the other microcontrollers I recommended all can be bought without headers soldered.

Headers pre-soldered is a big dealbreaker for me. I almost exclusively use JST-EH connectors for personal projects in place of headers. They are 2.5mm spaced so they fit in 0.1" spaced pins, and are much more secure than headers and won't easily get pulled out and jumbled up.

Oh wow, the TinyPICO is awesome! Back when I was hacking on the ESP32, this form-factor was uncommon and very expensive (a single guy on Tindie sold them). How is the antenna performance? I'm suspicious of anything that doesn't have one of those Proant thingies.

EDIT it even has 4MB PSRAM! Very, very nice.

EDIT2 ok it does have a Proant antenna, and its 20$, so not that cheap. But ok for what you get I suppose.

I haven't had any major issues with the antenna, although I've only really used it around my home Wi-Fi. It occasionally blips and I have some reconnection logic for that but overall it's been fine for indoor use. I have a DIY smart lock and DIY smart thermostat (that literally sit over the real lock and real thermostat -- I rent my apartment so I can't change those out) running off a TinyPICO each and they've been doing fine as far as the Wi-Fi connection goes. They just run a HTTP server on my LAN and I can set the lock and thermostat states with a simple REST API. (I can't stand the complexities around interfacing with Google Home and Alexa ...)

I also used a TinyPICO's BLE interface to connect a phone with a motor driver for a mini telepresence robot [0] though a TinyPICO was probably overkill for this use case. My thinking was really just future-proofing it in case I wanted to add more stuff to the robot.

BTW the Wi-Fi only seems to support 2.4 GHz. No 5Ghz.

[0] http://github.com/dheera/robot-tethys

Yeah still waiting for a new chip that has at least as much SRAM, number of cores and clock frequency as the original ESP32, but with integrated USB and 5Ghz WiFi. What Espressif have released so far are just cost-optimized variations.

One alternative with both 2.4/5GHz wifi+BLE is the RTL8720DN. More here: https://www.cnx-software.com/2020/01/17/realtek-rtl8720dn-du...

Until recently, the only devkit you could find was the Seeedstudio Wio Terminal. Just came across a devboard on AliExpress for < $6. Looks interesting.

I have briefly experimented with Mediatek and RTL wifi SoCs, but found SDK and documentation severely lacking / buggy. What’s your experience?

Is 5GHz matter for IoT use case?

Yeah, the TinyPICO has everything you'd want for building your own IoT device (e.g. a smart switch) but at $20 you might as well buy a pre-made device for the same price. If they could get the price down a bit more it could hit a real sweet spot. Still an awesome board though, kudos to them.

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