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One ESP32 pin controlling a shift register?

Posted by newbob 
One ESP32 pin controlling a shift register?
March 03, 2020 01:42PM
I stumbled upon an old article describing a simple way to drive a shift register with only one pin. This method utilizes input capacitance combined with the fact that shift register 'shifts' on rising clock edge to drive the Data input of the shift register.

[www.edn.com]




Variable duty cycle clock output seems to be a perfect application for ESP32 RMT peripheral. It has up to 80MHz resolution and combined with fast shift registers like MC74VHC595 [datasheet.lcsc.com] one ESP32 could, conservatively, drive 64 'virtual' pins with 8 real pins. To make it better one could use real pin to control STROBE instead of RCD network for faster and synchronized output across all 8 RMT peripheral pins.

Has this been done already?
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