ESP32 Forum

Hello I'm trying to design a custom PCB with an ESP32WROOM-E and im pretty new into PCB development.

I tried to use an ESP32 Devkit and it worked fine so I tried to copy the Schematics found here into KICAD. https://dl.espressif.com/dl/schematics/ ... v4-sch.pdf

For my project I want to connect an RFID module and 2 RGB LED's.

As attachment you can find the schematices I tried to copy into KICAD and the stuff I added to it.

1. Are my schematics okay or are there any misstakes or things I should change? Is there any need to improve the power supply for high power usage spikes?
2. Is there a similiar product to the LESD5D5-0CT1G which I can buy on Mouser?
https://eu.mouser.com/
3. why does the AMS1117 3,3V in the schematices only has 3 Pins when in reality it has 4?

best regards Alexander

I think your RxD and TxD are flipped. RxD and TxD normally are indicated as the direction as seen from the device the pins are on, so you'd want to connect RxD to TxD and vice versa. The devkit flips them around in the connections of the two 0 ohm resistors; you don't.

Also, the AMS1117 is a SMD part; while it looks like it has 3 pins and a tab, it actually only has 3 pads. Flip one over if you have them lying around; the tab and the center pin actually is one large pad.

The LESD5D5-0CT1G seems to be a pretty standard 5.6V breakdown voltage TVS/ESD diode. You should be able to select for that on Mouser ad just pick any of those parts, I'd think.

Thats exactly why I was asking for help you are completly right. I didnt see they flipped RX and TX in the DEVKIT Schematices thank you very much.
https://www.mouser.de/ProductDetail/Com ... pBeFVHVA==
Should this ESD protection Diode work too or do I have to ask this question in a forum for the CP2102?

Best regards
Alexander

That diode looks fine to me.

Hello, I have an other question:
What does the NC stand for on the 10K(5%)(NC) Resistor used in the UART / USB Bridge?

alexander96 wrote: ↑

Fri Apr 16, 2021 1:10 pm

Hello, I have an other question:
What does the NC stand for on the 10K(5%)(NC) Resistor used in the UART / USB Bridge?

NC normally stands for "Not Connected", but Im not sure what it means here, should the !SUSPENDED be grounded or not? sry

NC in our schematics when associated with a component means the PCB will have a footprint for that component, but it's not placed there when the PCB is pick&placed (I guess it stands for No Component?) It's useful if we're not sure if there needs to be a component or not, or in case there may be a niche reason someone wants to place a component there afterwards. In practice, you can assume that component is not needed for the normal function of the devboard.