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I am currently working on a prototype for an ESP32 retrofit for a home alarm system. I am an aspiring electrical engineer and will be attending Miami University next year.

I am having trouble getting my computer to recognize my USB connection to the ESP, despite having the correct drivers installed on my Mac. Even in the device inspector, my computer doesn't show the FT232 as connected. I have rebuilt the schematic twice on my breadboard with no luck. I have attached my schematic below which is based off the Sparkfun ESP32 Thing. Any suggestions?

EDIT: 3.3V is coming from a regulator circuit which is powering the ESP from 12V.

Schematic

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  • \$\begingroup\$ Where's your 3.3V coming from? \$\endgroup\$
    – Tom Carpenter
    Apr 22, 2018 at 21:03
  • \$\begingroup\$ And also, please post a screenshot of the PCB layout as well. \$\endgroup\$
    – Tom Carpenter
    Apr 22, 2018 at 21:04
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    \$\begingroup\$ How have you attached the FT232RL to a breadboard? USB signals don't like breadboards. \$\endgroup\$
    – Tom Carpenter
    Apr 22, 2018 at 21:06
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    \$\begingroup\$ Are you sure it's a real FT232? There have been issues of incompatibilities between FT232 drivers and fake/clone devices. \$\endgroup\$
    – user16324
    Apr 22, 2018 at 22:26
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    \$\begingroup\$ @MarkU schematic looks fine. Compared it with a design I've previously used and it matches (except mine didn't have R3/R4). \$\endgroup\$
    – Tom Carpenter
    Apr 22, 2018 at 23:10

2 Answers 2

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100 nF capacitor is missing on pin 17. It is needed for stability of internal 3V3OUT regulator.

Also, in all suggested application diagrams the VCCIO is tied to either VCC, or to 3V3OUT, which is an internal derivative from VCC. The configuration shown in OP question doesn't follow any of suggested diagram. I suspect that if the VCC and VCCIO are completely independent, internal POWER-ON-RESET might not function, and the chip logic may not start properly. It is highly recommended to follow manufacturer's suggested configurations precisely.

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Pin D + of the USB connector must go with pin 16 and pin D- of the same USB connector connects to pin 15.

The lines are reversed in your project.

I hope this observation is useful.

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    \$\begingroup\$ That's completely wrong answer. The wires are not reversed. DP is 15 and DM is 16. \$\endgroup\$
    – Justme
    May 27, 2020 at 17:54
  • \$\begingroup\$ echoing the above, this answer is completely wrong. \$\endgroup\$
    – VanGo
    May 27, 2020 at 18:01
  • \$\begingroup\$ "I hope this observation is useful." It isn't. It's simply wrong. \$\endgroup\$
    – Sébastien Dawans
    Aug 31, 2021 at 12:33

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