I have a bus pirate, and it is sitting on the shelf most of the time.

For serial, I end up using dedicated adapters. Terminal for text, custom python script for binary protocols.

For I2C, I have some USB dongles which appear as /dev/i2c-* devices. Use bash + i2c-tools to debug, then switch to python for more complex stuff.

For unusual protocols, I can use Arduino(clone) directly. Sometimes this needs a trivial interactive handler, like '2' to toggle CS2 line and 'x' to shift in 5 bits.

The problem with BusPirate is that you are not going to integrate it into your device, so whatever scripts you write to it will need to be rewritten for "real" thing. And its interactive mode is pretty limited and you grow out of it very quickly.

I own a bus pirate.

Today, I'd instead recommend a serial adapter based on FT232H or variants. Good UART speed, hardware handshake if needed, and a bunch of GPIOs.

I like this one personally:

https://makerdiary.com/products/pitaya-link

It's both a USB-UART bridge and a debug/programming adapter for ARM microcontrollers, for 11$.

Based on a microcontroller itself, with open firmware and some extra exposed pins so it's hackable if you wish (but it works fine ootb).

I have two of these configurable adapters, too. But i don't use them anymore. I don't have the control programs installed on every machine, i don't remember their settings... in the end of the day i always use the cheap ch340 one because its stateless, because it doesn't have any persistent settings. I grab one from the box and don't get surprises.

Today you are probably better off owning RPi-pico and just bitbanging (or in the rare case when it is needed the PPI comes in handy) the whatever bus you want to interface to in microPython.

For stuff like this (connecting to a router) you really want to have serial adapters. Because it may or may not work, and if it doesn’t work, a bus pirate or raspberry pi pico has a lot more variables to troubleshoot.

I've got a bus pirate, a JTAGulator, and I ordered a Glasgow over two years ago, but it's presently vaporware. I'm out the money and I'll be surprised if it ever arrives.