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esp32:esp32_main [2020/10/13 19:54]
admin [Espressif ESP32 Development Board]
esp32:esp32_main [2020/11/17 15:49]
admin [DAC and ADC]
Line 35: Line 35:
 === Special Hardware Configuration ==== === Special Hardware Configuration ====
  
-** The I/O pins are not 5V-tolerant! ** Use 3.3V instead.\\+** The I/O pins are not 5V-tolerant! **\\ 
 +Use 3.3V instead.\\ 
 +\\
 The build in LED is on GPIO 2.\\ The build in LED is on GPIO 2.\\
-GPIO 34 39 are input only. And don't have a software pull-up or pull-down functions. One has to use an external 10k pull-up resistor. Details are at  +\\ 
-[[https://learn.sparkfun.com/tutorials/esp32-thing-hookup-guide/hardware-overview|learn.sparkfun.com]].\\+GPIO 34, 35, 36, 37, 38 and 39 are input only. And don't have a software pull-up or pull-down functions. One has to use an external 10k pull-up resistor.\\ 
 +\\ 
 +GPIO 6, 7, 8, 9, 10 and 11 are used for the SPI flash chip and can't be used  for any other purposes.\\
  
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Line 107: Line 111:
 [[https://www.adafruit.com/product/3405|Adafruit HUZZAH32 – ESP32 Feather Board]]\\ [[https://www.adafruit.com/product/3405|Adafruit HUZZAH32 – ESP32 Feather Board]]\\
 [[https://learn.adafruit.com/adafruit-huzzah32-esp32-feather|Adafruit Learn Guid]]\\ [[https://learn.adafruit.com/adafruit-huzzah32-esp32-feather|Adafruit Learn Guid]]\\
 +
 +----
 +===== DAC and ADC =====
 +
 +**ADC**\\
 +
 +
 +[[https://www.malabdali.com/esp32-adc-and-dac/]]
 +
 +**DAC**\\
 +The ESP32 has two DAC pins, GPIO25 and GPIO26. The resolution is 8 bits.\\
 +   dacWrite(25, Value); // 255=3.3V 128=1.65V 0=0.0V
 +For generating a sine wave one finds a good manual here: [[https://www.xtronical.com/basics/audio/dacs-on-esp32/|DAC’s on ESP32]]\\
 +
 ---- ----