Best products from r/esp32

This ended up being my fix, thank you!


I was using my USB to Serial adapter to power the ESP32-CAM after uploading the sketch. When I was uploading, I had the adapter set to 3.3v and it connected to the 3.3v pin on the board.

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This allowed me to upload the sketch but the camera would not work.


I swapped the USB to Serial adapter to 5v, plugged the power into the 5v pin and POOF, it works!


I'm now running my ESP32-CAM off of USB breakout boards and they are working great.


Working on integrating these into Home Assistant now. Thanks!

If you want a hot fix, set pinmode to input instead of switching to high. Make sure there's no sort of pullup on the pin. I had good luck with the spi pins.

By setting it to input, the pin will hopefully go into a floating or hi-z state. If all is well, the relay will open when switched to input and close when switch to HIGH output.

Worked for me until I found some single 3v relays. You could also use transistors to convert signal to 5v.

If you are going to implement the proper POE spec then you will need to handle 48v with some power negotiations.

I would recommend just injecting 12v on one side and use a switching buck converter to convert it down to 3v3. 12v is a good middle ground so as not to loose power in the ethernet cable but still get a good voltage out the other side.

I use these: https://www.amazon.com/Generic-Splitter-Injector-Connectors-PT-POE-GSPK/dp/B00LV8X81I

but make sure not to mix with standard POE!

Adafruit is always going to be overpriced. Their ESP32 board is about the same price as the Sparkfun board. Avoid adafruit whenever possible, you can usually get the exact same stuff on Amazon or Ebay for a far better price.

You can't really go wrong with a $10 ESP32 dev board from Amazon or wherever. Once you learn enough about your first dev board, and decided you need something else, you'll know better what to purchase for your specific needs. You can get quite a lot done with just the simple $10 dev board. I wouldn't go with a custom-made dev board with an exposed ESP32 chip on it (like the Sparkfun board) - you should definitely use a dev board with the ESP32-WROOM module on it, like most of them out there. You would most likely be using the ESP32-WROOM (or WROVER) modules in any project you'll do, and learning how the ESP32-WROOM module works and its pinouts is invaluable knowledge you won't get with the Sparkfun board.

It depends. Test it out and see if it works.

If you’re driving that many LED arrays, you might want to use something like the SN74HCT245 as they’re pretty cheap.

Would it be easier perhaps to switch over to the esp32-wrover-b chip? For my project, I can’t use any development boards, so I’m thinking I can buy the Wrover chip and place the pins for the camera headers like how they are in this rover-kit Wrover kit by following the esp schematic.

I like the Lolin ESP 32 .

I like this one cause it has a built in OLED, GPIOs, and LiPo Battery Connection.

You can program these using Arduino, but I beleive you can program this using Micro Python as well.

Lolin also has a ESP 32 board that doesn't have the OLED, but does come with the GPIO, and LiPo connections. https://wiki.wemos.cc/products:d32:d32

I ordered these. Two for $13.25 and they work great.

If you just want the ESP8266, why don't you get one from Amazon Prime? Probably cheaper/easier than me shipping you a banged up one :)

https://www.amazon.com/Makerfocus-NodeMcu-Development-ESP8266-ESP-12F/dp/B01N3P763C/

Are you talking about actually deploying the ESP32 out somewhere, or just for development? You mention deployment, but why do you need both during deployment? What boards are you using? Most of the development boards have a micro USB connector on them, so I power them from a bog standard 5v micro USB power supply. You can get USB hubs that will power 10 boards from one hub.

In terms of powering from 3.3 volts, I've powered it from a benchtop power supply (temporarily), I currently use a linear regulator when running off a battery, I've used a couple step down converters, and for when I actually need 3.3V and 5V power I got a couple boards like this - super cheap and handy. All these are connected to whatever random power supplies I have around, leftover from old devices, salvaged, etc. I have a couple 120VAC -> 5VDC power supplies, but I rarely end up using them.

Maybe I'm misunderstanding, but you generally shouldn't be powering the boards via 5V and 3.3V at the same time (at least with the boards I have). Did that provide an answer to your question, or have I completely missed this one?

60 x .75 mA = 45 amps. That would be 225W on 5V, indeed.

You'll need a bigger power supply. I'd use two of those : https://www.amazon.com/JOYLIT-Transformer-Industrial-automation-Communications/dp/B07Q56X68J (the 40A model) to have a comfortable overhead.

At 22,5 amps each you'll have to take the wire gauge in consideration. You can't just use a smaller gauge and daisy chain them.

Building on @Robin_B's suggestion to use ESPNow, I'd have either a dedicated ESP as a server to aggregate data or let one of the sensors pull double-duty. Assuming you have cell service, once in a while the server ESP will send the data to the internet via cellular modem. The server could be a FiPy or any old ESP with a modem. If the modules are out of ESP-Now range, then use a ESP32 with an onboard Lora radio and give one of them a cell modem. Hologram.io will sell you a sim card for $5 that comes with 1MB/month of free data. Power each of your ESPs with a solar panel and a battery and now you only need to drive out if something stops reporting.

If you don't have cell service at the farm but you do in a nearby town, you could use a long range lora antenna to send the data from the aggregating ESP to another ~10km away where it could then be relayed to the internet.

Thanks so much, I looked up "ESP32-DevKitC" and found [this one] (https://www.amazon.com/dp/B01N0SB08Q/) for $14. Is that the board you're recommending?

It's a 3.2" inch diagonal ILI9341 tft display. It is touchscreen capable but I am not using that at the moment.

It's a 320x240 display and I spent $16.59 amazon.

LCD Display Module, 3.2 inch 240320 TFT LCD Display Module 4-Wire SPI TFT LCD Screen with SD Card Cage,TFT Display Module https://www.amazon.com/dp/B07KPD4DHD/ref=cm_sw_r_cp_apa_i_ag2SDbE0TNM5D

An easier way would be to use a microUSB extension cable: https://www.amazon.com/gp/product/B00W6URQPE

Helloo theere....

i'm usinig these:

https://www.amazon.com/Diymall-Voltage-Sensor-Dc0-25v-Arduino/dp/B00NK4L97Q

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addding 300 to the ADC value gets me back to accurate........

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Because the maximum you can feed into the pin is 3.3v which is 16.5 on the voltage converter........

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12.89 from battery 2.56 into the board......

so a perfect 5 scaling factor....

Doesn't it come with a backing? The first photo on the Amazon listing shows one.

https://www.amazon.com/gp/product/B0718T232Z/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

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it says Nodemcu on the back

Do you have a link? Lowest I found is this one for $11, which I may order one of just to confirm it will fit, but that’s still $4-$5 more than Ali.

That has proven to be less than intuitive. Which manual should I be consulting? I've got a "HiLetGo" ESP32S. Nothing came with it pointing to documentation. So I can find scads of docs for the ESP-WROOM-32 chip, but that doesn't tell me anything about the design choices made for the board itself (like which header pins connect to the GPIO pins). The way I eventually figured it out was flipping it over and realizing that they had printed (in very tiny text) the pin assignments on the back of the board. Programming the thing was also a bit confusing, because you have to push a switch labeled "IO0" down when the upload says "Connecting...___..." otherwise it times out. I've got another one that times out, even when you do that.

So, it's not like these little boards are without quirks, especially if you're used to a traditional Arduino. I agree with /u/holytoledo760. It appears the most sensible approach is to figure the thing out on a breadboard. I made the mistake of building a PCB with a bunch of connections before I really understood the thing's quirks. Now I'll have to design a new PCB most likely (unless I get really lucky).