Page 1 of 2

ESP32 Minimum Hardware

Posted: Sat Jun 24, 2017 9:31 am
by JohnKed
Hello to everyone!

I was starting to playing with the ESP32 and I have a hardware oriented question. The module I using is the ESP-WROOM-32.
What is the minimum hardware-peripheral components that I should use for this module?

For example with the ESP8266 the minimum hardware/peripheral components for best results looks like this:
http://esp8266.github.io/Arduino/versio ... serial.png

Have we got anything similar for the ESP32? For example and pull-up/pull-down resistor from a specific pin to vcc/ground?

Re: ESP32 Minimum Hardware

Posted: Sat Jun 24, 2017 6:40 pm
by f.h-f.s.
You can take a look at the devboard schematics viewtopic.php?t=344
olimex has public schematics https://github.com/OLIMEX/ESP32-EVB/blo ... _Rev_B.pdf

Re: ESP32 Minimum Hardware

Posted: Sat Jun 24, 2017 8:38 pm
by JohnKed
Thank you f.h-f.s. !
That was really helpful!!!

Re: ESP32 Minimum Hardware

Posted: Sat Jun 24, 2017 10:15 pm
by loboris
Minimal hardware you need to use ESP32 module is USB to ttl UART adapter like this one
http://www.ebay.com/itm/6Pin-USB-2-0-to ... SwKIpWER5M
and two buttons to put the module into bootloader mode.
To avoid soldering the wires directly to the module, I would recomend minimal breakout board like this one
http://www.ebay.com/itm/ESP-32S-Support ... SwiDFYPVWe
And, of course, some 3.3V, min 500mA power supply.

Or, all on one board:
http://www.ebay.com/itm/Hot-ESP-32S-Blu ... SwB-1Y24vO

Re: ESP32 Minimum Hardware

Posted: Sun Jun 25, 2017 3:48 am
by ESP_Sprite
Specifically, be sure to use a 3.3V PSU that can actually deliver 3.3V @ 500mA or so. If the ESP32 crashes somewhere around the time WiFi is initialized, most likely your power supply isn't beefy enough.

Re: ESP32 Minimum Hardware

Posted: Sun Jun 25, 2017 10:02 am
by JohnKed
Thanks alot to everyone of you!

Another simple question! I want to connect an SD card to the ESP. I am using the Arduino core.
It seems that they are using those connections to connect the sd card: https://github.com/espressif/arduino-es ... braries/SD

But on the ESP Wroom 32 datasheet here: https://www.espressif.com/sites/default ... eet_en.pdf
they are specifying other pins for SD usage (shared with the local memory).
Which pins should I use for my project (using Arduino)?
Mainly I want to store and manipulate text files on the SD card, mp3 files and possible run ESP32 firmware code from there.

Any suggestions?

Re: ESP32 Minimum Hardware

Posted: Sun Jun 25, 2017 12:11 pm
by loboris
If you want to use Arduino, follow the Arduino instructions.
It is not possible to run ESP32 firmware code from SD card.

Re: ESP32 Minimum Hardware

Posted: Sun Jun 25, 2017 3:53 pm
by JohnKed
loboris wrote:If you want to use Arduino, follow the Arduino instructions
Ok, I will! Thanks loboris!
loboris wrote:It is not possible to run ESP32 firmware code from SD card.
Can at least write a .hex file or .bin file or something to the SD card and flash the ESP32 from the SD card?

Re: ESP32 Minimum Hardware

Posted: Sun Jun 25, 2017 6:17 pm
by loboris
JohnKed wrote:...Can at least write a .hex file or .bin file or something to the SD card and flash the ESP32 from the SD card?
It is possible, you could modify the OTA example to do that. But, I don't know if it is possible from Arduino...

Re: ESP32 Minimum Hardware

Posted: Mon Jun 26, 2017 3:52 pm
by martinayotte
Since the OTA is working in Arduino, it should be possible as @loboris said by modifying the OTA example and taking the bits from SD files.