Developer Ha Thach has given Adafruit a vacation reward: the flexibility to make use of a Raspberry Pi RP2040 microcontroller to program one other RP2040 microcontroller by offering a “Twin Position” simulated USB port.
“We crank out numerous RP2040 microcontroller boards,” explains Adafruit’s Phillip Torrone, “and so we now have to have the ability to program them very quick and really reliably. Traditionally we used a Teensy 3.6 to run our programmer+tester ‘brains’ — specifically we favored that it had USB Host assist and a microSD Card slot so we may retailer the goal UF2 [firmware] after which burn it over the MSD interface.”
All was properly, till the element shortages started to chew — and the Teensy 3.6 turned tougher and tougher to search out. “We ran out a number of months in the past,” Torrone explains. “But, we can not let that stand in the way in which of us making new {hardware}! Due to [Ha] Thach’s arduous work, we now have added USB Host bitbang assist to TinyUSB in order that the RP2040 can faux to have a second USB port and it really works very properly!”
The modification to TinyUSB, a cross-platform embedded stack designed to offer USB Host and/or Machine assist, signifies that the RP2040 microcontroller can present two USB ports — the bodily port and a second “pretend” port. This “pretend” port is used to program the goal machine over USB Mass Storage — finishing the method in simply two to a few seconds.
To go along with the brand new TinyUSB functionality, Adafruit has designed a “Brains Board” based mostly across the Raspberry Pi Pico that totally replaces the outdated Teensy 3.6 variant — and has confirmed that it’s going to even be switching its {hardware} testing boards to make use of the Raspberry Pi Pico as properly.
The “Twin Position” supply code is now obtainable on the Adafruit TinyUSB GitHub repository, below the permissive MIT license.
