P-Star 25K50 Micro (top) and P-Star 45K50 Mini SV (bottom).
The Pololu P-Star microcontroller boards are a family of general-purpose programmable modules based on the PIC18F25K50 and PIC18F45K50 microcontrollers from Microchip, which have 32 KB of flash program memory, 2 KB of RAM, and built-in full-speed USB functionality. The P-Stars add on-board components and connectors that support the microcontroller and make it easier to use. Each board ships with a USB bootloader that makes it easy to load new programs without using an external programmer.
The P-Star requires a USB A to Micro-B cable (not included) to connect to a computer.
Features and specifications
- Programmable Microchip PIC18F25K50 or PIC18F45K50 microcontroller
- 32 KB flash (8 KB used by bootloader, leaving 24 KB available for user program by default)
- 2 KB SRAM
- 256 bytes of EEPROM
- Native full-speed USB (12 Mbps)
- 2 PWM output signals (one of which can be sent to four different pins)
- 5-bit digital-to-analog converter (DAC) output
- 5 V logic voltage
- Internally clocked at 48 MHz, resulting in execution speeds up to 12 million instructions per second (MIPS)
- Precision 16 MHz crystal
- Three user-controllable LEDs
- USB Micro-B connector
- Can be powered from USB or external source regulated to 5 V by on-board regulator
- Reverse-voltage protection on external power input
- Ships with a proprietary USB bootloader developed by Pololu for the P-Star (see Section 6)
- Bootloader is usable from Windows, Linux, and Mac OS X with open source software
- No external programmer required
- Compatible with standard Microchip compilers, development tools, and programmers
P-Star comparison table
|P-Star 25K50 Micro||P-Star 45K50 Mini SV|
|User I/O lines:||19||30|
|Operating voltage:||5.5 V to 15 V||5 V to 36 V|
|Regulator type:||linear||switching step-down|
|Regulated current:(1)||100 mA||500 mA|
|Auxiliary 3.3 V regulator:|
|Dimensions:||1″ × 0.6″||2.0″ × 0.7″|
|Weight:(2)||1.3 g||3.5 g|
1 These values are rough approximations for comparison purposes. Available current depends on input voltage, current consumed by the board, ambient conditions, and regulator topology.
2 Without included optional headers.