Adafruit Teases RP2040 Circuit Pyrate

Communicating with integrated circuits and electronic devices can present a challenge when prototyping or debugging projects and designs. One option is to use a microcontroller to accomplish the communication, however this also requires developing code to interface with the devices. An additional option available is to use a device such as the Bus Pirate. The Bus Pirate enables users to communicate with devices using protocols such as I2C, SPI, JTAG, asynchronous serial, and 2- and 3-Wire libraries. The major benefit the Bus Pirate provides is that only a serial terminal is needed to communicate with the devices. It also has additional benefits of being able to program AVR microcontrollers and being completely open source. The Bus Pirate has been a very popular hacking tool for a while now, unfortunately it has become harder to get (like many other devices) and may not be back in stock anytime soon.

As a result, Adafruit is tinkering around with the idea of releasing their own version of a Bus Pirate. Meet the Circuit Pyrate! Instead of a PIC microcontroller, an RP2040 would be used for communication and interfacing to devices. This introduces the advantage of added memory as well as usage of the RP2040’s programmable IO (PIO). The RP2040’s PIO offers a major upgrade here. They can basically be used to create any interface that may be needed to communicate with other devices. It is also possible to use them to create interfaces that are completely custom and do not exist yet. Using internal state machines and shared memory, the PIO can act as a completely separate microcontroller to handle GPIO communications.

llDespite the advantages the RP2040 offers, there is still challenges and questions that need to be worked out. First, the original Bus Pirate has an interface that is tolerant of voltages from 0 – 5.5V. The RP2040 natively works at 3.3V and consequently will require some sort of logic level conversion to interface with 5V devices. The current implementation uses a Zener diode and resistor that should let it tolerate 3.3V and 5V devices. But this method has the disadvantages of limiting bandwidth and constantly pulling a small amount of current, which makes it less energy efficient. While this may work for a proof of concept, additional ideas are currently being explored. Another challenge being faced is matching the pin outputs exactly to the original Bus Pirate. However, as alluded to previously, the RP2040’s PIO should allow for a universal interface to accomplish this task. In addition, the Adafruit board is planning on featuring a separate STEMMA QT port, NeoPixel, and LEDs for the power outputs. It is not guaranteed we will be seeing the Adafruit Circuit Pyrate for sale, though with a lack of Bus Pirates on the market it would be a welcome addition.