Issue with this little circuit, can someone help me ?

(deleted)

So that we do not all have to download the image

You don't say which GPIO pin you're using (GPIO0 or GPIO2), but if you're using GPIO0, that circuit will tend to pull it low on boot which will make the ESP-01 go into the programming mode rather than the run mode. You should probably use GPIO2 to drive the transistor and have a pull up to 3.3 V on GPIO0.

Also, and not related, check the Vf of your I.R. Leds. IIRC, they are usually 2.2V not 1.5V (like a RED LED).

(deleted)

Hi,

Did you check the voltages? Check the pin voltage output to see if it is 3.3 and the +5 volt feeding the leds.

123Splat:
Also, and not related, check the Vf of your I.R. Leds. IIRC, they are usually 2.2V not 1.5V (like a RED LED).

No. Wavelength ~ energy of photons ~ voltage drop of LED. There is probably some quantum physics hidden and I am no sure if it holds for all materials without exception but in general the longer is wavelength the lower is forward drop of LED. So IR led should have lower forward drop than red. It should depend on it’s peek wavelength.

Hi,
If you want to see if your IR LEDs are working, look at them with your digital camera, most are sensitive down to the IR region of the spectrum.

Phone camera should work.

Tom... :slight_smile:

Keyword is MOST camera's.... It got me once, OnePlus does add a IR filter... ::slight_smile:

(deleted)

GPIO0 and GPIO2 must both be high for a normal boot. As mentioned, your external circuit must be pulling it low.

Use a small n-channel mosfet instead of the npn. One that has gate threshold voltage of 2V or less. Then you can have a 10K pull-up on GPIO2.

Add a small signal PNP transistor between ESP and 2N2222.
Emitter to 3.3volt, 10k from GPIO to base, ~330ohm from collector to base of 2N2222.
Leo..

edit: logic is now reversed...

Hi,
Have you got 22uF across the output of the AMS1117 as per the data sheet, your link shows a PCB but nothing like a 22uF fitted.
Also what are you using for 5V source and what voltages do you measure on the input and output of the 1117 during startup.
The 1117 has 1.3V dropout, so your input voltage should not drop to 3.3 + 1.3 = 4.6V.
1117.jpg

Tom.... :slight_smile:

1117.jpg

(deleted)

Mopheus:
I think the problem could be related with the PaulRB comment, that GPIO2 is acting as LOW and that's affecting the boot mode of the ESP, I'm considering getting that mofet or a PNP to test that theory.... but not exactly sure what I can get here in Argentina and models....

It's a bit of a hack, but in the interim you might try something like 330 Ohm pullup between GPIO2 and 3.3 V. That should hold the input high enough on boot (about 2.65 V) and the GPIO is strong enough to pull it down. The LEDs would be on until the boot completed and the GPIO was configured and set low, but that probably doesn't matter.

Hi,
Your 1117 board does not have the 22uF capacitor fitted.
Please add one and see if it helps.

Tom… :slight_smile:

(deleted)

Mopheus:
Ops… really ? Ok… my very bad… 22uF of what type of cap should I buy ? Ceramic ? And where should I put it ?

Thanks a lot Tom, didn’t realize that…

Does your board look like the picture from the DX.com link in your first post? That picture shows four capacitors on the board and the fixed 3.3 variant of the 1117 so it would surprise me if the capacitors weren’t already there. I expect the circuit is one big and one little capacitor on both Vin and Vout and the reference pin tied to ground.

That said, ESP-01s are very sensitive to power supply layout so the leads between your power board and the ESP should be short and relatively heavy gauge wire. It wouldn’t be a bad idea to add a bypass capacitor on the pins of the ESP-01 using a low reactance capacitor (ceramic or tantalum) of a few tens of microFarads.

More to the point, I believe PaulRB has correctly identified your issue in post #10 and the various workarounds identified in that post, post #11, or post #14 should correct it.

MrMark:
It wouldn't be a bad idea to add a bypass capacitor on the pins of the ESP-01 using a low reactance capacitor (ceramic or tantalum) of a few tens of microFarads.

The ESP8266 draws about 80mA, but a few hundred mA during short (transmit) bursts.
A linear regulator might have problems delivering that peak current.
A low ESR cap of a several hundred uF on the 3.3volt line is wise.
I have used 2* 220uF/6.3volt tantalum in my latest design.
Leo..

(deleted)