{"product_id":"adafruit-555-pwm-output-stemma-1-5k-25-khz-or-1-5-250-hz-stemma-jst-ph-2mm","title":"Adafruit 555 PWM Output STEMMA - 1.5K~25 KHz or 1.5~250 Hz - STEMMA JST PH 2mm","description":"\u003cp\u003eA fully-assembled 555 timer board with adjustable PWM square-wave output.\u003c\/p\u003e\n\u003cp\u003eHow many times have we heard \"hey you could have just replaced that microcontroller with a 555\"? Maybe 555 times! But we always find wiring up a timer chip to be a bit of a pain, you need quite a few components - especially if you want a buffered output. That's why we designed the\u003cstrong\u003e\u003cspan\u003e \u003c\/span\u003eAdafruit 555 PWM Output STEMMA\u003cspan\u003e \u003c\/span\u003e\u003c\/strong\u003e- a fully-assembled 555 timer board with adjustable PWM square-wave output.\u003c\/p\u003e\n\u003cp\u003eWe originally came up with this idea when someone requested we make a 'PC Fan Dummy' board, that can generate a 100Hz signal for faking a PC fan's tachometer signal to a motherboard. But then we thought that sometimes we want a square wave for driving a piezo, or as an audio input, or to modulate an IR signal. So we made it a little more general-purpose.\u003c\/p\u003e\n\u003cp\u003eYou can select between two 'ranges': approximately 1.5K~25 KHz or 1.5~250 Hz. The onboard trimmer pot will tune the actual output between those values. You can use a logic analyzer, oscilloscope, multimeter with frequency-counting, or even an audio input jack on a computer, to determine the precise value if you need more than a rough number. The output is a DC square wave, driven by a\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/www.digikey.com\/en\/products\/detail\/nexperia-usa-inc\/74HC1G04GW-125\/1022913\"\u003e74HC1G04\u003c\/a\u003e\u003cbr\u003ebuffer so it can sink\/source up to 12.5mA.\u003c\/p\u003e\n\u003cp\u003eYou can power the board from 3V to 12VDC, an onboard regulator will pin the input to the 555 and buffer to 5V max. That means that between 3V and 5V power, the signal peak will be at the same logic level as the power. Above 5V, the output will be pegged to 5V.\u003c\/p\u003e\n\u003cp\u003eEach STEMMA board is a fully assembled and tested PCB but no cable. No soldering is required to use it, but you will need to pick up \u003ca href=\"\/en-au\/products\/jst-jumper-3-wire-assembly\" rel=\"noopener\" target=\"_blank\"\u003ea 2mm pitch, 3-pin STEMMA JST PH cable\u003c\/a\u003e. Alternatively, if you \u003cem\u003edo\u003c\/em\u003e want to solder, there's a 0.1\" spaced header for power\/ground\/signal.\u003c\/p\u003e\n\u003ch2\u003eTechnical Details\u003c\/h2\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/www.adafruit.com\/includes\/templates\/shop2019\/images\/RoHS2_2011_65_EU.svg\" alt=\"RoHS 2 2011 65 EU Compliant\" width=\"145\" height=\"80\"\u003e\u003cimg src=\"https:\/\/www.adafruit.com\/includes\/templates\/shop2019\/images\/RoHS2_2015_863_EU.svg\" alt=\"RoHS 2 2015 863 EU Compliant\" width=\"145\" height=\"80\"\u003e\u003c\/p\u003e\n\u003ch2\u003eLearn\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/learn.adafruit.com\/adafruit-555-pwm-output-stemma\"\u003ePrimary Guide: Adafruit 555 PWM Output STEMMA\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003c!----\u003e","brand":"Adafruit","offers":[{"title":"Default Title","offer_id":56500167672181,"sku":"ADA5963","price":3.29,"currency_code":"GBP","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0389\/1025\/files\/5963-00.jpg?v=1766148612","url":"https:\/\/wholesale.pimoroni.com\/en-au\/products\/adafruit-555-pwm-output-stemma-1-5k-25-khz-or-1-5-250-hz-stemma-jst-ph-2mm","provider":"Pimoroni Wholesale","version":"1.0","type":"link"}