I have attached the basic design of what I am using to build the circuit. The issue that I am having is that the esp32 is it is not receiving enough current on start up, it is only drawing up to 80mA when I measure with my multimeter. It is going to be using BLE and wifi so the max current draw on start up should be about 200mA. I know there should be enough current available because the power supply is rated at 2.5A and the voltage regulator has a max of 1A so it should be able to draw enough through. The TFT screen is also only drawing around 80mA as well, not sure if that means anything for cause of problem as I think it should draw more.
The 7805 does have an appropriate heatsink attached, so I am pretty sure it is not thermal shutdown. It also cannot be an issue with the board it self because it will run with the 12V connected up, to the 5V input (not smart to do, but needed to test).
I am really racking my brain here I have been trying to solve this for a while. I am only do this as hobby and I am learning on the go so any help would be greatly appreciated.
Does it work if you don't connect the rest of the circuitry? You forgot the decoupling capacitors for the whole 3.3V part. I also don't know what specs the 3.3V regulator on the ESP32 has.
The onboard 3V capability is not much (there's no standard, varies by manufacturer etc.)
Disconnect everything and plug things back in till the trouble comes back.
thanks for the replies,
I have tried disconnecting the rest of the circuit, the problem still remains when I am drawing power through the regulator. If I bypass the regulator, with any other power source to the 5V pin it will work. Also I am pretty sure the onboard 3.3V regulator is an AMS117, if that is of any use. I have tried placing a capacitors at the 5V pin but it didn't make a difference, not sure if that is because I didn't incorrectly though.
Why do you use a 12volt supply when everything needs 5volt.
Why do you power two audio amplifiers from the 3.3volt supply of the ESP32 instead of 5volt.
That 3,3volt supply is only designed to power the ESP, and maybe only a few sensors.
Leo..
P.S. The ESP32 draws AFAIK close to 500mA on startup.
A cheap/thin/long USB lead can already give bootup problems on USB power.
Running current is AFAIK about 80-100mA, with short peaks during transmit up to 500mA.
The peak current of a ESP32 / ESP8266 is about 250 mA as far as I know.
The voltage regulator on the ESP32 board can give that, but there is not much left for other things. So it can be used for sensors, but not for motors or those amplifiers as TomGeorge wrote.
I think that the 7805 is a counterfeit. It has to go anyway, it does not belong in your project.
Let's no longer think about what is wrong, let's go for a good solution.
A DC/DC-converter from 12V to 5V and another one for the 3.3V. If you make the 3.3V from the 5V, then you can also power your project with 5V. Both converters for 3A or so. The amplifiers powered by 5V.
The very cheap modules on Ebay might cause noise or do weird things without load. Don't bring nasty things into your project when there is no need to. Take a pick from good modules: https://www.pololu.com/category/131/step-down-voltage-regulators.
Two good DC/DC-converters will take half the costs of your project. That's just how it is.
I did consider using DC/DC converters but I was concerned about the RF interference with them on the BLE and wifi because they end up being close to each other. Yeah you weren't joking about the price it will end up costing neat $100 to get the parts, not sure if I want to spend that much on just 2 parts. I took in the advice and switch the amplifiers over to the 5V.
I'll repeat, and I know the cruel prospect of step-by-step is a soul-crusher around here, but you have to bust this all down to the 7805 and the ESP32. If that's good, then connect other modules till the trouble comes back. You should add the module and cycle power (sys re-boot) each time.
And you need to comprehend the difference between switchmode converters operating at perhaps hundreds of kilohertz and producing harmonics perhaps up to tens of Megahertz, and BLE operating a 2.4 Gigahertz.
Hi,
I can see two electro capacitors on the output of the 7805..
Where is the input bypass cap?
You do have all those gnd strips connected together?
I kind of suspect you have some gnd problems.
Can I suggest you do a very careful reverse engineer and draw your circuit?
Draw it by hand.
You are in trouble shooting mode now, so you need to logically approach your project and checking your circuit is first. Reverse engineering is a good way to check.
