I'm a 14-year-old boy currently working on a project involving a small NAS (Network-Attached Storage) using an ESP32 Wrover and three SD cards. I designed the PCB myself, and everything is working well except for one issue. The problem arises when I attempt to use Wi-Fi in my code, and the brownout detector is triggered. After researching other posts, I understand that this issue is related to the power supply for the ESP32.
Could someone please assist me in resolving this hardware problem? I have included my schematics for reference. Thank you!
Edit : Here are the message I receive :
21:34:43.002 -> Brownout detector was triggered 21:34:43.002 -> 21:34:43.002 -> ets Jun 8 2016 00:22:57 21:34:43.002 -> 21:34:43.002 -> rst:0xc (SW_CPU_RESET),boot:0x33 (SPI_FAST_FLASH_BOOT) 21:34:43.002 -> configsip: 0, SPIWP:0xee 21:34:43.002 -> clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00 21:34:43.002 -> mode:DIO, clock div:1 21:34:43.002 -> load:0x3fff0030,len:1344 21:34:43.002 -> load:0x40078000,len:13964 21:34:43.002 -> load:0x40080400,len:3600 21:34:43.002 -> entry 0x400805f0
Schematic_Tiny Synology NAS_2023-09-22.pdf (64,0 Ko)
You actually did a great job, even better you are speaking the language of electronics; schematics! The major problem I see is you are missing filter and decoupling capacitors, they filter out noise and add bulk reserve for the regulator. I will take a SWAG and say your voltage regulator is either collapsing and/or oscillation when you load it up. I will guess it will leave a burn mark on your finger especially if there is no heat sinking. Look at the manufacturer's datasheet for the regulator and it will tell you what you need in capacitance, they are not all the same. They will also probably tell you the type, be sure to follow that. I will guess this is a through hole design so a hint Capacitors (SMD [Surface Mount Devices]) can be soldered between the pins of the regulator.
Hello,
Thank you for your assistance! I will follow your suggestions and let you know the results. Also , this is a SMD design and not a through hole one 
.Thanks once again for your help!
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Would it be something like that ? (The datasheet is in Chinese so it is more difficult to understand even with traduction)
Edit : I tried that and it still does the brownout detect trigger
The power supply is inadequate. The MCU power supply should be able to supply at least 500 mA at 3.3V with no significant voltage drop.
SD cards are very power hungry when reading and writing, and need another 100-200 mA each, so aim for 1 Ampere total current draw.
Why do you think you need 3 SD cards?
For the power supply , I tried with a phone charger and the ports on my pc .Also, I'm not using an SD card at the moment, so that's not what's causing the problem. Also , I need 3 SD card because I am doing a tiny NAS ans the "Drive" have each one SD/TF card inside to act like a real hard drive.
The power supplies you mention are 5V. The 3.3V regulator needs to be able to supply 1 Ampere for the project. Also, fix the decoupling and filter capacitor problem mentioned above.
I have one of these ,
and I have a 1 amp power supply with it. Do you think that the usb port on it would provide the 1 amp needed? Also , I added capacitor like in the datasheet but there was no change in the error.
The datasheet for the HT7533-1 is a mess, and does not state the maximum output current. It states only the "typical" current of 100 mA.
I suspect this regulator is completely inadequate for your project, and recommend a professionally designed 3.3V regulator module, like this one.
So I would really need a Step-Down Voltage Regulator and not a linear voltage regulator?
You can use either one. I do not recommend that you try to design your own until you completely understand the requirement for decoupling and filter capacitors.
ALWAYS follow the manufacturer's recommendations for decoupling and filter capacitors, found in any professionally prepared data sheet (the HT7533 data sheet is not a good example).
Ok, I'll take this as a last option if the others don't work. Thanks!
Would this be a good choice considering only one SD card will be written to at a time?
Have you read the AMS1117 datasheet, and determined whether it meets the project requirements?
Well on the product page , it says that it can provide 800 milliamps (Up to 900~1500 ma) at 3.3v and my project would only use about 700-800 milliamps . So yes it meets the project requirements. But I was more asking me if a cheaper one like that is still good compared to the pololu one.
Espressif recommends to follow the hardware design guide lines of this document (attached).
esp32_hardware_design_guidelines_en.pdf (6.4 MB)
Hello , thanks for helping . But the document you provided are only for the people making the esp32 module. But in my case , I bought the esp32 module.
Which one of the following, you have bought -- Fig-1 or Fig-2?
Figure-1:
Figure-2:
Envoi en cours : 16954766940522754255081030505454.jpg…
This is the one I have , so only the Esp32 Wrover module like in fig-1 but mine is an Esp32 Wrover
