The P-Star 25K50 Micro is a tiny programmable module featuring Microchip’s PIC18F25K50 microcontroller.
It packs a Micro-USB interface and 19 digital input/output pins onto a board measuring only 1″ × 0.6″ and ships preloaded with a USB bootloader, so no external programmer is required.
The Pololu P-Star 25K50 Micro is a general-purpose programmable module based on Microchip’s PIC18F25K50 microcontroller, which has 32 KB of flash program memory, 2 KB of RAM, and built-in USB functionality. On-board features of the P-Star (abbreviated P*) include a 16 MHz crystal, a USB Micro-B connector, and three user-controllable indicator LEDs. A voltage regulator and power selection circuit allow the board to be powered from either USB or an external 5.5 V to 15 V source, while a resettable PTC fuse on the USB VBUS supply and reverse protection on VIN help protect it from accidental damage. The board ships with a USB bootloader that makes it easy to program the PIC microcontroller without using an external programmer.
The comprehensive user’s guide provides the basics you need to get started with the P-Star 25K50 Micro as well as detailed technical information.
This product requires a USB A to Micro-B cable (not included) to connect to a computer.
- Dimensions: 1″ × 0.6″ (1.05″ × 0.6″ including USB Micro-B connector)
- Programmable Microchip PIC18F25K50 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)
- 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
- 19 I/O lines in a small package
- 16 user I/O lines along the sides of the board
- 3 additional I/O pins available in other locations
- 14 pins can be configured as analog inputs
- 2 PWM output signals (one of which can be sent to four different pins)
- 5-bit digital-to-analog converter (DAC) output
- Three user-controllable LEDs
- USB Micro-B connector
- Can be powered from USB or external source regulated to 5 V by onboard regulator
- Operating voltage: 5.5 V to 15 V
- Can operate down to 3.8 V with decreased logic voltage
- Reverse-voltage protection on external power input
- PTC fuse on VBUS supply
- Ships with a proprietary USB bootloader developed by Pololu for the P-Star
- 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
- Comprehensive user’s guide
For more information about the PIC18F25K50 microcontroller and its peripherals, see Microchip’s PIC18F25K50 documentation.
- Size: 0.6″ × 1.05″ × 0.18″1
- Weight: 1.3 g2
- Processor: PIC18F25K50
- RAM size: 2 Kbytes
- Program memory size: 32 Kbytes3
- Motor channels: 0
- User I/O lines: 194
- Minimum operating voltage: 5.5 V
- Maximum operating voltage: 15 V
- Logic voltage: 5 V
- Reverse voltage protection?: Y5
- External programmer required?: N
- PCB dev codes: pc01a
1Without included optional headers. This measurement includes the USB Micro-B connector, which extends 0.05″ past the edge of the PCB.
2Without included optional headers.
38 KB of the MCU's 32 KB of flash memory is used by the pre-installed USB bootloader. All 32 KB is available if you use an external programmer and erase the bootloader.
4All 19 can be used as digital I/O, 14 can be used as analog inputs, and one can be an analog output. 16 of the 19 are available along the sides for use in a breadboard.