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esp32

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esp32 boards

solderstation.jpg

Blinky

esp32.jpg

  • ESP-Strapping
    • GPIO
      • GPIO12 float low - low 3.3v, high 1.8v (VDD_SDIO)
      • GPIO15 float high U0TXD - high logging, low silent
      • GPIO 0 float high, GPIO 2 float low - Flash boot
      • GPIO 0 gnd low, GPIO 2 float low - Serial boot
    • ESP32-S pins
      • pin25 - programming
      • 1,38,15 - GNDs
      • 2 - pwr, 3 - enable
      • ADC1 (ADC2 unavailable w/ wifi)
  • Sep 2019
  • Oct 2019
    • Move ADC port to an ADC1 Pin pin4-9
    • Another ADC Pin to 3.3v input?
    • Another ADC Pin to vdivider + 15v input
    • Add 3.3v to top of ADC
    • drop 3.3io and 3.3 power ports
    • add oled/serial port at edge
    • short rx/tx lines pin34&pin35
  • Nov-B 2019 (send to pcbs.io)
    • LMS8117AMP-3.3/NOPB
    • LCD pin23 DO, pin16 CLK. (any GPIO)
    • POWER idle 115mA with esphome
    • POWER 16 neopix 17ma(low) 177ma (full red or green or blue) 305ma full white
      • POWER neopix 20ma per color per led
  • Nov-C 2019
    • Reset line (no room)
    • connected 3v bus
    • vreg cap
    • volt Divider ADC (no room)
    • add pullup resistor to one port (for i2c temp sensor)
    • U0 TX 500ohm R close to esp32 (reflections)
  • Dec-D 2019
    • move pin20 (SD1 CLK) to 12 G27
    • add 4-pin switch port (switch+status led)
    • LVDS connector
    • GPIO12 1.8 vs 3.3v pin14
    • flip micro USB

photoresistor

  • super-bright (from cell phone) 300KOhm
  • super-dark (fabric lightly covered) 10MOhm

signal harmonics

esp32.1577831329.txt.gz · Last modified: 2024/01/31 04:08 (external edit)