Space, other hobbies, Covid, and career have displaced Arduino over the past 4 years.
However, we’ve reclaimed our basement and I’m setting up a dedicated space!
What notable key developments have surfaced in the past 4 years? Hardware, libraries, etc!
If I were to buy you a coffee and/or beers (travel to SW Missouri and I will!) , what would you tell me about the past 4 years of the Arduino world?
some key words to research
32 bits processors and the rise of ESP32
demise of GPRS, more WiFi and other radios like LoRa and BLE
machine learning
IoT
UWB
Lidars
3.3V instead of 5V
Because of the chip shortage, things have changed. The Arduino Team has forgotten about the normal average beginner and hobby user. So now the ESP32 and the Raspberry Pi Pico are good boards. The ESP8266 is out, because there are a number of variations for the ESP32.
There is a simulator "Wokwi" that can simulate a lot. Not only the Uno, but also the Mega, the ESP32, the Raspberry Pi Pico and other boards. It can be used in a serious way, but also in a fun way: ServoOverdone.ino - Wokwi Arduino and ESP32 Simulator
MicroPython and CircuitPython are used more and more.
I would say some trends that began 4+ years ago have continued, but for the most part things are pretty much the same. There have been no dramatic revolutions.
Uno and Uno clones continue to outsell all other arduino types, as they have for many years, and beginners still insist on connecting Unos to breadboards with rat's nests of wires.
Old and outdated designs of sensors and motor drivers like DHT11 and LM298 still feature in many projects that beginners come to the forum with help with.
So from your point of view, the good news is that you haven't fallen behind Arduino technology over the last 4 years. Perhaps that's not what you were hoping to hear!
ESP32's or other 32 bit micro controllers, Beagle Bone's (64 bit), Raspberry Pi's (64 bit). Machine Learning. IoT. MQTT Broker. pubsubclient library, RTOS. Image processing. Tensor Flow Lite.
Web Editor (IDE in Cloud)
Arduino IoT Cloud
a new desktop IDE
Nano Every and Uno WiFi with ATmega 4809
new Nano boards with different 32bit MCU SAMD, nRF52, RP2040
WiFi boards with uBlox NINA (esp32) as WiFi and BLE adapter and the coresponding WiFiNINA library and ArduinoBLE library
new popular 3d party board is Raspberry Pico with RP2040 MCU and the Pico W with added WiFi module
new Arduino Pro boards with 'big' STM32 MCU
A lot of new interesting parts and break out boards.
Better and new libraries. Unfortunately some of the outdated ones are still around. Some parts have multiple choices for libraries and it is not clear which one to use. For example the DS3231 has multiple, sometimes conflicting, libraries with same named but slightly different functions.
As previously mentioned new processor options. I mostly stick with the classic AVR parts and esp8266 variants. I have been looking at the ARM variants and the ESP32, but so far haven't had projects that require the power.
Good news - I have a few ESP32's - some with LCD screens, but 4 years ago there was an under-abundance of projects leveraging the ESP32's true powers. I'll go see what people are doing. Thanks!
I have reliable, never-been-updated, 5-year-old IoT (intranet) setup running
And I am deathly afraid to try to update anything 
Is this a good thing?
Ooh, being addicted to ChatGPT I'll have to dig into this one...
Yes.
Good!
Just googled that. Holy bajunkajunk! 
I ordered 2 regulars and 2 W's. These things look amazing!
Wow, great! 4 years ago, these sorts of things were not very usable, but they felt so close.
EXCELLENT. I have a few Circuit Pythons and similar devices. I love the idea of the actual code being stored on the device itself, but 4 years ago library support was seriously lacking.
Thanks for the updates!
Beginners are weird.
I never got super deep into motors, but want to really learn the motorized stuff now. Are there any recommended drivers now?
For the DHT11 alternative, my pile of BME280/BMP180's still relevant?
Thanks for the insight!
I'm skeptical.....
Started tinkering with this, and I like it!
Whoa.... serious research binge material there... Thanks!!
Any chance there's one that enables multitasking better than the famous millis() method of the past?
Maybe I should just start learning newer devices...
The ESP32 comes with freeRTOS as its built in OS.
A multitasking multithreading OS.
Arduino recently created an experimental "Arduino_Threads" library and framework for the boards that use an Mbed OS-based core:
Not that I know of, other than the FreeRTOS versions of ESP chips. (The esp8266 has a FreeRTOS version, but I don't think it is supported in the Arduino IDE.)
We forgot to mention something: counterfeit parts.
A MPU-6050 with one axis not working, a DS18B20 that stops working at 75°C, and so on.
Your pile of BME280/BMP180 sensors are okay to use (if they are not counterfeit).
The Wokwi simulator can also run CircuitPython and Rust.
Wokwi can create an Arduino Uno with more (fake) SRAM, so that problem is solved 
If my ESP32 is 5 years old, do I need to flash the latest FreeRTOS?
No, if you upload a sketch then everything is renewed.
The basic bootloader in the ESP32 is always the same thing.
All ESP32's come with the OS freeRTOS. You may have to refer to the documentation of the older model ESP32's.
