OnBoard – A New Grants Program to Fund $100 in PCB Costs for Teenagers

I wouldn't want a USB-based Picoprobe debugger or logic analyzer to depend on (or even use?) wireless connectivity. And for a low-latency game controller adapter which translates between wired NES/SNES, N64/GC, and/or USB protocols, converting a regular controller to a Bluetooth controller is quite an invasive change which requires adding batteries to the device, and increases input latency/unreliability when you're using a wireless connection, so many adapters don't bother with networking.

In terms of whether WiFi or Bluetooth is a wise idea (as opposed to being cool or useful), I find that wireless/networked protocols are easier to get wrong than simpler configuration. I have a video scaler (GBS-Control) which exposes a network-based interface over the ESP8266's Wi-Fi adapter. The IP address it picks up in my LAN is random, and though you can visit gbscontrol.local to resolve the URL using mDNS, this is unsupported on older versions of Android. And in certain video modes, the video circuitry interferes with the wireless signal, causing network requests to stall indefinitely.

In my observation, networking is especially prone to race conditions. If I toggle my power strip and power on both the ESP8266 and my router at the same time, the ESP8266 boots before the router, fails to connect to the router (remembered by PersWiFiManager), and decides to expose its own access point and never reconnect to the existing router afterwards. Worst of all, the web server used runs networking code in the yield() callback, leading it to handle network requests in the middle of I2C communication call stacks and possibly overflow the stack. It's also known to corrupt heap memory when concurrent HTTP requests occur (https://github.com/me-no-dev/ESPAsyncWebServer/issues/324 was closed by a bot without a solution). I found an concurrency footgun where the server allows HTTP callbacks to ask the server to reply with a SPIFFS file handle, but you can reopen and write to the file in subsequent code after the HTTP callback finishes, but before the server finishes streaming data from the file handle. This results in corrupted data being sent to the HTTP client.

I also heard that the Pinecil V2 released with a Bluetooth Low Energy compatible microcontroller, but the wireless-enabled firmware apparently malfunctions on certain irons and causes them to fail to boot (https://github.com/Ralim/IronOS/issues/1661), though this may be fixed over time.

Depends on use case, for me at least, I have used RP2040s as secondary microcontrollers for something like a CM4, where I want something that is closer to real time, or if it is a control loop.

You should look at atiny10s too, they have a 6 pin and through hole version and you can use them without a crystal.

I have thought about making a design for one and doing a series where we make an assembler in python, where it's an exercise in writing a parser to output the binary assembly for use in a simple micro like the atiny. They have limited registers and instruction set, so would be a good way to help people understand what is happening.