{"title":"Adafruit PyRuler - Engineer Reference Ruler with CircuitPython","handle":"adafruit-pyruler-engineer-reference-ruler-with-circuitpython","url":"/products/adafruit-pyruler-engineer-reference-ruler-with-circuitpython","description":"The Adafruit PyRuler is a PCB reference ruler and a fully functional CircuitPython microcontroller in one. Measuring approximately 25 × 150 mm (1\" × 6\"), this gold-plated FR4 ruler features common SMD component package outlines, a font size guide, trace-width diagram, and AWG wire gauge drill holes — all the references an electronics engineer needs at a glance.\n\nBuilt into the end of the ruler is a Trinket M0 (ATSAMD21 Cortex-M0+) with four capacitive touch pads and matching LEDs. Out of the box, it ships with CircuitPython and can act as a USB keyboard — touch the pads to type special characters like Ω, µ, and π. Edit the on-board code.py file in any text editor to customise the behaviour.\n\nKey Features\n\n\nPCB Reference Ruler – Gold-plated with SMD package outlines, font sizes, trace widths, and AWG drill holes\n\nATSAMD21E18 Processor – 48 MHz Cortex-M0+ with 256 KB flash and 32 KB RAM\n\n4 Capacitive Touch Pads – Each with a matching coloured LED (red, yellow, green, blue)\n\nUSB Keyboard Mode – Type Ω, µ, π, and custom characters by touching the pads\n\nCircuitPython Pre-Loaded – Shows up as a USB drive; edit Python code in any text editor\n\nArduino Compatible – Can also be programmed with the Arduino IDE\n\nNative USB – Serial console, HID keyboard/mouse, and small disk drive\n\nRGB DotStar LED – Plus green power LED and red pin 13 LED\n\n5 GPIO Header Pins – 3 ADC, 1 DAC, 2 PWM, 3 extra capacitive touch; not shared with USB or touch pads\n\nHardware SPI, I2C & Serial – True hardware support on dedicated pads\n\nNeoPixel & DotStar Support – Drive 8,000+ pixels with DMA on one pin\n\nUSB or Battery Power – Automatic switchover between USB and external power\n\n\nIdeal For\n\nElectronics engineers needing a quick SMD package reference\nCircuitPython beginners looking for an easy first project\nCustom USB keyboard shortcuts and special character input\nDesk accessories and engineering gifts\n\n\nResources\n\nAdafruit PyRuler Learning Guide\nTrinket M0 CircuitPython Guide\n","vendor":"Adafruit","product_type":"physical","in_stock":true,"options":[],"variants":[{"id":5034,"title":"Default Title","sku":"AF-4319","price":24.97,"on_sale":false,"in_stock":true,"available_quantity":92,"option1":"Default Title"}]}