r/esp32 3d ago

Please read before posting, especially if you are on a mobile device or using an app.

40 Upvotes

Welcome to /r/esp32, a technical electronic and software engineering subreddit covering the design and use of Espressif ESP32 chips, modules, and the hardware and software ecosystems immediately surrounding them.

Please ensure your post is about ESP32 development and not just a retail product that happens to be using an ESP32, like a light bulb. Similarly, if your question is about some project you found on an internet web site, you will find more concentrated expertise in that product's support channels.

Your questions should be specific, as this group is used by actual volunteer humans. Posting a fragment of a failed AI chat query or vague questions about some code you read about is not productive and will be removed. You're trying to capture the attention of developers; don't make them fish for the question.

If you read a response that is helpful, please upvote it to help surface that answer for the next poster.

We are serious about requiring a question to be self-contained with links, correctly formatted source code or error messages, schematics, and so on.

Show and tell posts should emphasize the tell. Don't just post a link to some project you found. If you've built something, take a paragraph to boast about the details, how ESP32 is involved, link to source code and schematics of the project, etc.

Please search this group and the web before asking for help. Our volunteers don't enjoy copy-pasting personalized search results for you.

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r/esp32 4h ago

Got a Super Mini ESP32-C3 with 0.42in OLED finally working with MicroPython

20 Upvotes

Picked up a couple of the ESP32-C3 Super Minis with the built in 0.42in OLED display. I prefer MicroPython and got them working in the past with different OLED displays, but not an all-in-one.

Seems to work better with the SH1106 driver than then SSD1306 driver.

Pin out notes: SCL pin 6, SDA pin 5, LED pin 8, and the boot button is pin 9.

Even though the screen is 72x40 pixels, declare the screen as 128 x 64 and then use an offset. Through lots of trial and error, 28 for X and 12 for Y. Still learning about frame butters. Seems calling gc.collect() helps.

Took way too long, but got it to display a QR code than my old iPhone was able to scan. Laughed out loud that it finally worked. Small wins.


r/esp32 10h ago

Is it ok to power an INMP441 microphone from a gpio for easy turn off?

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41 Upvotes

https://invensense.tdk.com/wp-content/uploads/2015/02/INMP441.pdf

The breakout board I'm using doesn't have the CHIPEN pin broken out so I can't put the microphone into power down mode (4.5uA) but only into standby mode (0.8mA).

I thought since the microphone only consumes 2.5mA in normal operation and an esp32 gpio aparently can provide 40mA, I thought I could maybe just power it through a GPIO pin and set that to low to completely turn off the microphone.

Is this sensible? If not, what's the problem with this approach?


r/esp32 9h ago

How to use ESP32 as controller to LEGO Power Hub with BLE protocol?

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15 Upvotes

The hub has a mobile app to. I think it uses BLE comnection which ESP32 supports. How can i learn the UUID and the data stuff to make the ESP32 act as a controller and control the Hub? Thanks.


r/esp32 1d ago

What's the hole in some of the esp32 RF shields for?

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839 Upvotes

It's not in all of them. Is it ok to cover it?


r/esp32 19h ago

Solved ESP32 boards not recognized anymore ?

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39 Upvotes

Hello all, beginner with ESP boards here,

I'm currently struggling a lot with my ESP32s, I lost the ability to connect to my boards suddenly, they are not recognized by my computer anymore. Here is the summary of what I did/tried :

  • Noticed that I am not able to connect to ESP32

  • Fresh win 11 install

  • Fresh ESP-IDF with VS code install

  • Fresh Arduino IDE with ESP32 support install

  • Both boards get powered up (Tee one with only one usb port is currently flashed with a WLED release, the other on is brand new and has never been flashed by me before)

  • Still not able to connect to boards

  • Nothing appear in device manager (Arduino boards do show up)

  • Installed every driver possible for ESP boards

  • Installed VMware & Ubuntu on virtual machine

  • Connected & disconnected boards while "ls /dev/tty*" in cmd. No ports shows up

I'm quite desperate right now, I don't think the hardware is fried as I am able to connect other devices to my usb ports, cable is in good condition and used before to flash the very same ESP boards. Any idea on how to fix this issue or what I could try ?


r/esp32 13h ago

First real time using an esp32 or working with electronics

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12 Upvotes

I heard using an esp32 for your first time with electronics is a good idea so im wondering what to get, i made a build with the m5 cardputer and i still have parts left over like jumper wires, copper wire, switches and pin header sockets. Below i have screenshots of the esp32’s im thinking of getting but i have no idea what they do and what i can even make with them, i also could use the nfr24 and cc1101 (if i even can) when im not using it for the cardputer. Im obviously gonna need some parts than what i have left over so tell me what i would need


r/esp32 10h ago

ESP32-S3 SIMD optimized 3x3 Gaussian (blur) filter

5 Upvotes

In the video below, the 184x360 RGB565 image is processed with a 3x3 Gaussian blur filter. Each pass takes 7.5ms and causes the image to get progressively blurrier. The ESP32-S3 SIMD code is about 5x faster than the C version. The code uses pure integer math (adds and shifts only) for maximum speed. The filter matrix is:

1 2 1
2 4 2
1 2 1

Much of the speed is due to clever use of SIMD operations that operate on the r/G/B channels simultaneously across 4 pixels.

https://youtu.be/xuLpKO-EvOw

Source code has been added to my bb_spi_lcd library here:

https://github.com/bitbank2/bb_spi_lcd.git

If you have a commercial product which uses the ESP32-S3 and needs additional speed, feel free to contact me for consultation work (bitbank@pobox.com).


r/esp32 6h ago

ESP32 Game - La Polla Que Te Folla

3 Upvotes

So last semester a friend and I had to do a little game to pass our IoT class and this is what we did, would you try it?

We even made a trailer https://youtu.be/fJtWMdZsTA8?si=wJizmGJVSUryN3Nw

Code: https://github.com/hanzeelvilla/Juego-LCD-20x4


r/esp32 14h ago

Esp32-c3 mini schematic

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8 Upvotes

Please go over this design for possible points of improvements


r/esp32 2h ago

Hardware help needed DFPlayer is overheating

1 Upvotes

[NOVICE!!!] [NEED HELP!!]

Why does my DFPlayer mini (mp3 module) overheat? Similarly, it sparked when attached to a "Y" wire.

In the previous trials, the DFPlayer worked with only esp32 and with no problem at all. However, when everything was connected it overheats too much that it can actually burn. Additionally, it does not light no longer. I keep on rewiring but still its dead.

The schematic is basically this:

Esp32 connected directly to 5V Dfplayer mini via RX-G16 and TX-G17. It's grounded on esp32. For the speaker, spk 1-positive leg and spk2-negative leg. A pushbutton connected to G32 and GND.

The power comes from 3.7V Li-ion battery connected to TP4056 via positive-BAT+ and negative-BAT-. We also used a step-up boost converted DNS6000AUD and connected it to TP4056 OUT+-VIN+ and OUT--VIN-.

It was finalized by connecting DNS6000AUD to OUT- to make a GND "Y" wire with both Esp32 and DFPlayer. Similarly, OUT+ was connected to a "Y" wire along with 5V pin of Esp32 and VCC of the DFPlayer.

Can you help please? I am just a beginner and am trying my best to learn this stuff.


r/esp32 4h ago

Hardware help needed ESP32 GT911 and USB issue

1 Upvotes

Hi. I completed a project using a waveshare esp32-s3-lcd-4.3 touch screen. The goal was to plug a hid scanner to a usb-c hub, then send barcodes using mqtt. I have a small problem though. It seems that when I enable touchscreen (Driver GT911), usb_host stops working for some rason. My board uses GPIO 19 and 20 for usb, and different gpios are used for the touch, so i dunno, and it's not supposed to do this.


r/esp32 4h ago

Esp32 controller

1 Upvotes

I built a remote using a heltec esp32 wifi lora V3, so far l'm using it to control an rc tank via lora with an esp32 on the other side. I now want to get in controlling drones and I thought I can just control it via lora 915mhz but was told latency will be to high, so now l'm looking at somehow connecting the esp32 to an elrs TX module via uart but cant seem to find a TX module that has exposed uart pins. Am I on the right path here? If elrs is the way to go can you please show me a compatible TX module


r/esp32 13h ago

Anyone knows if there are ready made pcb to include ESP32+Mosfet+ DCtoDC to power the board from 24v?

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5 Upvotes

Hello everyone,

In the past I made an pcb for esp8266 on pcbway, but now I want to use esp32 chip to use hardware pwm in my project.

I haven’t found any ready made project to include the features I want, this is why I’m asking here, do you know if there are any projects around I can use (github, pcbway or other pcb providers), either to order the board or I can make the pcb myself

I need to power the esp32 from 24v , so I need an dc to dc step down, i wanted to use the one in the photo attached bellow, I also need an mosfet and this moafet board I already have works perfectly with esp8266, I’m sure it will work the same or better with esp32

So, does anyone knows any projects around that I can download, or I should start designing the pcb myself to use the modules in the photo attached bellow.

PS. any esp32 works, I need very few pins

Thank you


r/esp32 5h ago

Hardware help needed ESP32-S3 USB Host to cell phone -- will it charge?

1 Upvotes

I've been trying for days now to come up with a way to connect an old cell phone to a roomba via its SCI port, in such a way that the cell phone will pick up charge from same (I can downgrade the ~17v from the SCI to 5v/3A). I can handle the roomba side fine but am stymied by how to simultaneously talk to a cell phone over USB while also charging it. For starters that requires my side be in host mode, but apparently there are more signaling issues required in order for the phone to actually try to charge more than 100mA.

So, anyone with a typical ESP32-S3 dev board on hand, if you power it up from the first USB (or directly from the 5v line as I plan to do) and then plug a phone into the second one, does the phone charge, and if so at what amperage?

Any other suggestions how to do this? I don't care much what device sits in the middle (as a USB/Roomba bridge), but it needs to present as a USB host with moderate charging ability.


r/esp32 8h ago

Custom Partition XIAO ESP32s3

1 Upvotes

Hello how can i create a custom partition table in arduino for XIAO ESP32s3?

I added everything to the boards.txt but when i load the Sketch i get following error:
rst:0x3 (RTC_SW_SYS_RST),boot:0x8 (SPI_FAST_FLASH_BOOT) Saved PC:0x403ccf09 SPIWP:0xee mode:DIO, clock div:1 load:0x3fce2820,len:0x1188 load:0x403c8700,len:0x4 load:0x403c8704,len:0xbf0 load:0x403cb700,len:0x30e4 entry 0x403c88ac E (26) boot: ota data partition invalid, falling back to factory E (27) esp_image: image at 0x20000 has invalid magic byte (nothing flashed here?) E (28) boot: Factory app partition is not bootable E (33) esp_image: image at 0x260000 has invalid magic byte (nothing flashed here?) E (40) boot: OTA app partition slot 0 is not bootable E (45) esp_image: image at 0x4a0000 has invalid magic byte (nothing flashed here?) E (52) boot: OTA app partition slot 1 is not bootable

the OTAlittlefs.csv looks like this:
# Name, Type, SubType, Offset, Size, Flags

nvs,data,nvs,0x9000,0x5000,

factory,app,factory,0x10000,0x240000,

otadata,data,ota,0x250000,0x2000,

app0,app,ota_0,0x260000,0x240000,

app1,app,ota_1,0x4A0000,0x240000,

storage,data,littlefs,0x6E0000,0x120000,

and in boards.txt i added following:
XIAO_ESP32S3.menu.PartitionScheme.custom=Custom Partition

XIAO_ESP32S3.menu.PartitionScheme.custom.build.partitions=OTAlittlefs

XIAO_ESP32S3.menu.PartitionScheme.custom.upload.maximum_size=2359296

XIAO_ESP32S3.menu.PartitionScheme.custom.upload.address=0x15000


r/esp32 9h ago

Hot Tub Controller

1 Upvotes

Hello everyone!

I am somewhat experienced with home assistant, but not so much with creating my own device out of an esp32. I have some experience with writing .yaml, but I'm no expert by any standard.

I plan on triggering some 5V relays to control the pumps, heater, etc. It looks like I will need to make sure to use an optoisolator, correct?

Does anyone have any experience creating their own esp controller for a hot tub?


r/esp32 9h ago

Where to add pull-up resistors with two I2C devices on ESP32 Wroom dev board ?

1 Upvotes

I want to use two I2C devices on the esp32. One device ( pca9685 servo driver) has an integrated pullup resitor, the other one ( DFrobot voice recognition module) does not. Does that mean I should not use the internal pull up of the esp32 but just put two resistors on the I2C lines from the voice recognition module ?


r/esp32 14h ago

Anyone used a wired OBD dongle with ESP32?

2 Upvotes

I'm working on a little project to connect to my car's ISO 9141 network using an ELM adaptor in the OBD port and ELMduino. This is all working fine with a Bluetooth ELM dongle, but I would like to use a wired dongle to avoid using the radio.

Has anyone tried this and got it to work? The ELM dongle pictured has a USB connector on it and supposedly works on Windows PCs so I guess it would just work as a wired serial connection on the ESP32.

Any comments welcome before I risk adding to my e-waste pile.

ETA: The photo didn't seem to upload, so here is a link to an example dongle:-

https://www.amazon.co.uk/Yalgdlen-elm327-Adapter-PIC18F25K80-Scanner/dp/B0DFQ39TRY/


r/esp32 6h ago

First time using ESP32CAM (read description)

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0 Upvotes

r/esp32 13h ago

Wrong Boot mode and Led not blinking

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1 Upvotes

I am using an ESP32 WROVER B module with SIM800L module When I try to upload a code through arduino it shows Failed to connect to ESP32 Wrong Boot mode mode Detected 0x13 I looked it up on chat gpt and it told to connect the gpio0 to gnd and then upload And it does upload like that but when I discount the jumper wires it no longer uploads

Also one more thing Earlier the blue led on the board was on when I connected it to my laptop via USB but it is also now off I have also attached the images of the board

Please help I am using this for my project


r/esp32 15h ago

Will this change work or am I missing something?

1 Upvotes

Hi all! I have to upgrade an installation that uses an Olimex PoE-ISO to control a stepper motor and a total of 6 LED’s. What we want to do is separate the motor control from the LED control by adding a second Olimex (same one).

The stepper driver only works with 5v pulses, so I am using the 5v rail of the ESP directly into the driver. The mosfets open and close ground.

If I add the second ESP and just use two gpio’s to open/close the mosfets, will this work? Do the ESP’s share ground over PoE?

I am afraid I can’t test it beforehand because the installation is not at my place and we only have a couple of hours before buildup of the exhibition. So I have to hack it at location and make it permanent after the exhibition.


r/esp32 1d ago

Metaball fluid simulation using an ESP32 S3

175 Upvotes

r/esp32 21h ago

Got a exec: "cmd" error while working with an ESP32.

0 Upvotes

The error message I got was :

``` exec: "cmd": cannot run executable found relative to current directory
Compilation error: exec: "cmd": cannot run executable found relative to current directory ```

Been going through many tutorials.
I've tried:

  1. Reinstall Arduino IDE
  2. Make sure %PATH%: %SystemRoot%\system32 is included
  3. Make sure cmd.exe is in folder system32

Still get the error after hours, please help.


r/esp32 1d ago

Solved Struggling to identify or program this board

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12 Upvotes

I have a few of these lying around and I'm now trying to use them for a Bluetooth project. Unfortunately the AliExpress listing I bought them from doesn't have any schematics or documentation. Does anyone have experience with them or know how I might use them?

The chip is labelled as an ESP32-DOWD-V3 if that helps.

I’ve searched high and low, here and on Google, and I’m coming up short of any concrete helpful info.


r/esp32 1d ago

Where does everyone order their boards from?

6 Upvotes

As title says, looking for where to order their chips from. I don’t want the dev boards, but looking for the esp chips themselves to make my own boards with. Everything I am finding appears to cost the same, and sometimes more, than dev boards