ESP32-WROVER-UE Hobby project checkout

[bonon14]

Hello, i'm here to ask you for a favor. I'm selfmade hobby electronic trying to desing his own weather station. I get my knowlage from documentations and studying similar designs. I belvie that i may miss something while designing it. I would appreciate if anyone could check if everything would work. Thanks in advance

[ESP_Sprite]

I see a few issues:
* I think you have your DP and DN switched.
* You do not want C13; it'll pull the ESP32 into download mode every time you power on the device.
* A WS2812B has a minimum high level of 0.7V*Vdd, which in your case is 3.5V. The ESP32 will output at max 3.3V, so that won't work (or at least not reliably); you'll need a level converter or some other shenanigans there.
* At 220 ohm and an 12V input, D2 will get something like 45mA through it. Depending on the LED, this can be way too much.
* Also, if you invert the polarity of your input voltage, the circuit will be saved because D1, but depending on its breakdown voltage you may blow D2s socks off.
* If JP1 is closed and you feed the device via USB, your VDD5 will probably be pretty low as U2 needs to regulate 5V input to 5V output.
* You have a bunch of signals on connectors, and if this is a weather station, there may be long-ish wires there. I'd think about ESD protection on those.
* The logic around S1 is a bit weird. If you are using that to have indicator LEDs that you can also disable, the LEDs will indicate the inverse of the signals you have (low = led on, high = led off)
* Enabling S1 may overrule the (weak, because 1K series resistor) signal from your USB-serial chip... you may or may not be fine as you picked a blue LED, but the situation is a bit precarious regardless.
* J2 is not actually connected to the RX signal.
* What is C11 for?

[bonon14]

* I think you have your DP and DN switched.

Noted and changed.

* You do not want C13; it'll pull the ESP32 into download mode every time you power on the device.

Noted and changed.

* A WS2812B has a minimum high level of 0.7V*Vdd, which in your case is 3.5V. The ESP32 will output at max 3.3V, so that won't work (or at least not reliably); you'll need a level converter or some other shenanigans there.

I'll investigate

* At 220 ohm and an 12V input, D2 will get something like 45mA through it. Depending on the LED, this can be way too much.

Noted, gonna recalculate the resistor

* Also, if you invert the polarity of your input voltage, the circuit will be saved because D1, but depending on its breakdown voltage you may blow D2s socks off.

Do you mean breakdown voltage of D1? Should i redesign it? can you point me what documentation should i read or some design examples? I would like to learn some better ways to protect it.

* If JP1 is closed and you feed the device via USB, your VDD5 will probably be pretty low as U2 needs to regulate 5V input to 5V output.

USB is only for programming purpose and VDD5 is not required because all devices using 5V would be disconnected at that time.

* You have a bunch of signals on connectors, and if this is a weather station, there may be long-ish wires there. I'd think about ESD protection on those.

As above could you point me some ways to protect it?

* The logic around S1 is a bit weird. If you are using that to have indicator LEDs that you can also disable, the LEDs will indicate the inverse of the signals you have (low = led on, high = led off)

I expected that cause it was designed all by myself. I just wanted to have switchable LEDs indicating tx and rx of programmer, and ticks of anemometer and rain gauge (D8 and D9 are connected to those instruments. Those are just reed swtiches, so ON is actually line pulled down)

* Enabling S1 may overrule the (weak, because 1K series resistor) signal from your USB-serial chip... you may or may not be fine as you picked a blue LED, but the situation is a bit precarious regardless.

Anyway to correct it? changing resistor? or dump that idea

* J2 is not actually connected to the RX signal.

Noted and changed.

* What is C11 for?

I saw it on someone else's desing so i thought it's required

I really appreciate you indepth review. Thanks a lot

[ESP_Sprite]

* Also, if you invert the polarity of your input voltage, the circuit will be saved because D1, but depending on its breakdown voltage you may blow D2s socks off.

Do you mean breakdown voltage of D1? Should i redesign it? can you point me what documentation should i read or some design examples? I would like to learn some better ways to protect it.

I mean the reverse voltage D2 can handle. Usually a LED can't really handle more than 5V or so if you apply it in the reverse direction (i.e. the direction where it doesn't light up). Easiest way to fix this is to connect the LED after D1, rather than in front of it.

* You have a bunch of signals on connectors, and if this is a weather station, there may be long-ish wires there. I'd think about ESD protection on those.

As above could you point me some ways to protect it?

There's a lot of ways, dependent on the environment the device needs to work in, the length and type of wires, the requirement wrt reliability etc. In your particular case (reliability not very critical, not really a noisy environment and supposedly not very long cables) I'd simply whack an TVS diode (google is your friend wrt those) between your signal line and ground.

* Enabling S1 may overrule the (weak, because 1K series resistor) signal from your USB-serial chip... you may or may not be fine as you picked a blue LED, but the situation is a bit precarious regardless.

Anyway to correct it? changing resistor? or dump that idea

There's not really a great way to fix it, but you may not have to, as long as you keep the color of the LED blue. (If the relevance of the color of the LED puzzles you: blue LEDs have a Vf of something like 3V, while for e.g. red LEDs, it's more like 1.8V.) If it still doesn't work, you could make R15 a bit higher, like 470 ohm or even 1K.