Challenger+ RP2350 BConnect datasheet

The Challenger+ RP2350 BConnect is a small extremely powerful embedded computer based on the new dual core Cortex-M33/RISCV RP2350 from Raspberry Pi. Also featuring 8MByte of FLASH memory and 8MByte of RAM

The Challenger+ RP2350 BConnect is an awesome board to start digging in to the new features of the RP2350. We paired the RP2350 micro controller with a 8MByte high speed flash capable of supplying data up to the max clock speed as well as an 8 MByte XIP RAM. The flash memory can be used both to store instructions for the micro controller as well as data in a file system and having a file system available makes it easy to store data in a structured and easy to program approach. With the RAM you can now store huge amounts of data as well as execute code giving a hole new heap of possibilities.

The board can be powered from a Lithium Polymer battery connected through a standard 1.25 mm connector on the side of the board. An internal battery charging circuit allows you to charge your battery safely and quickly. The device is shipped with a programming resistor that sets the charging current to 500mA. this resistor can be exchanged by the user to either increase or decrease the charging current, depending on the battery that is being used.

Short introduction to the board

PCB
The board is based on a popular form factor called “Feather” which is created and maintained by an American company called Adafruit. The entire specification for the Feather format is available here. The size of the PCB for the module is 50.80mm x 22.86mm but the entire module is a little bit bigger as the Type C USB connector protrudes about 1 mm outside the board.

Antenna
On the opposite end from the USB connector the WiFi antenna is mounted. When mounting the board into any enclosure you should make sure to keep stuff like cables and/or walls from the enclosure away from the antenna as much as possible. Anything mounted in the vicinity of the antenna will affect its performance.

Headers
On each of the longer sides of the PCB there are holes intended for soldering pin header connectors. If you don’t want to use connectors for some reason you can also solder a wire directly into the hole, making a permanent connection to your external device. If you go this way please make sure that the wires are fixed in place, otherwise vibrations can cause the wire to brake at the soldering point.

LED’s
On each side of the USB connector there is a small indicator LED placed. The LED which is marked CHG is the charge control indicator. This red LED will shine whenever the connected battery is being charged, and when the battery is fully charged the LED will turn off again. If you haven’t connected a battery to the board this LED will not come on at all.

On the other side of the USB connector there is a user programmable green LED. This LED is connected to pin D13 and can easily be controlled by the user program.

Finally there is a neopixel LED on the board. This is an RGB LED with intensity control, run by a single GPIO (D14/GPIO11) pin on the board. There are several good example libraries that can be used to drive this LED. An example can be found here.

BConnect
The board is equipped with two BConnect connectors that allow you to connect an array of different peripherals based on the BConnect standard. You can read more about this standard here https://ilabs.se/bconnect/ Having dual channels means that you can operate both a Bi2C peripheral as well as a BSerial peripheral at the same time.

Hardware details

Pins

The on board micro controller (RP2350) have a number of communication channels that have been routed out to the side (header connector) connectors.

• UART – One UART channel have been routed to the header pins (RX, TX).
• SPI – One SPI channel have been routed to the header pins (SCK, SDO, SDI).
• I2C – One I2C channel have been routed to the header pins (SCL, SDA).
• Analog pins – The micro controller have 4 analog input pins that all are available on the header pins (A0-A3).
• PWM – All pins can be used for PWM.

The pin chart below shows the placement of all pins and their respective functions. When working in an Arduino environment (or Platform IO) use the blue pins when writing your code and when working with CircuitPython use the orange marked pin assignments.

Power

The board can be powered from multiple sources. The most obvious way to run the board is by plugging it in to a USB cable and attach it to your computer. In this mode you can write software and test the board with all its functionality.

The board can also be powered from the USB pin using a 5V source. Make sure you connect to this pin using a schottky diode to avoid having the external 5V collide with the voltage from the USB connector.

There is also a third way to supply the board. This way is more invasive and will disable the onboard 3.3V power regulator.

You will have to pull the EN header pin low and then supply your own 3.3V voltage on the 3.3V header pin. Please note that when disabling the onboard power regulator you will have to supply the 3.3V also when running the system on battery power.

Battery

As described earlier the board can be powered from a LiPo battery. The battery is connected using a standard 1.25 mm JST connector on the right side of the board. If the battery is an integral part of the system that you are designing it is possible to connect the battery through the BAT pin instead. The charge controller will charge your battery in both of those scenarios.

Switching between the battery voltage and the applied USB voltage or external 5V is done seamlessly by the on board circuitry.

Charging of the battery is done by either connecting a USB cable or by connecting a 5V power source to the header pin marked USB on the board. If you do this make sure you connect your voltage through a 1A schottky diode to avoid any excessive current draw in the system when the two levels are slightly different.

Please note that providing external charger circuitry could destroy the internal charger on the Challenger board.