1st time user ESP-01 - working on USB adapter but not on PSU

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Re: 1st time user ESP-01 - working on USB adapter but not on

By aledrus
- Mon Jan 29, 2018 1:54 am #73549 Hi guys, thanks for the replies.

I am actually having the opposite effect of what both of you are saying.

If I boot up the ESP-01 with GPIO0 set to 3.3V (with a 10k resistor), the ESP-01 won't run the internal program.

I had to disconnect the GPIO0 to make it run the program when plugging it in.

What both of you are saying is that GPIO0 needs to be pulled up when booting - but if I pull it up, it won't run the internal program. (is booting the right terminology to say "when power is given to the ESP module"?)
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Re: 1st time user ESP-01 - working on USB adapter but not on

By aledrus
- Fri Feb 02, 2018 3:14 pm #73660 I have no idea what I'm doing guys.

I changed some code in the firmware to blink on LED_BUILTIN and now the ESP-01 just won't boot. I don't know what it was originally whether it was digitalWrite(pin1) or digitalWrite(pin2) or digitalWrite(pin0). Can't get it working again.

What is the ultimate minimum connections I need to make the ESP-01 boot in operation mode?

I have VCC connected to +3.3V
I have GND connected to 0V
I have CH_PD connected to 10k resistor to +3.3V
I have RST connected to 10k resistor to +3.3V

I pullup GPIO2 to +3.3V and the blue led doesn't come on at all. Or it comes on and stays on forever.

I pullup GPIO0 to +3.3V and the blue led doesn't come on at all, or it comes on and stays on forever.

The only way I could get it to operational mode is to plug in VCC, CH_PD, and RST to 3.3V. Turn on the AC PSU, wait 1 second then plug in GND.

Or alternatively I connect GND, CH_PD and RST to the AC PSU, wait 1 second then plug in VCC - this is the second method I could get it to work.

I have no idea what I am doing.
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Re: 1st time user ESP-01 - working on USB adapter but not on

By aledrus
- Sat Feb 03, 2018 9:09 am #73670 Hi, thanks for the reply.

The link you provided, like so many others, only tells you how to reset the ESP into flash mode. It doesn't really tell you how to connect it to normal mode.

Some tutorials say I must pull CH_PD high. Some tutorials say I must put CH_PD low but put RST high. Some say I have to put GPIO2 high.

I have tried all these combinations and they sometimes work but at other times the same configuration fails. It fails maybe 20% of the time. If I mix up most of those combinations it would work 80% of the time but will fail another 20% of the time.

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But I think I have a breakthrough. I cut off a USB cable and used the 5V from the USB to the LM 1117 chip that converts 5V to 3.3V. When I use a USB cable to power the LM1117 chip, so far the ESP works as expected 100% of the time regardless of my connections (I think I can power up the ESP-01 only with VCC and GND alone but I don't remember at the moment).

Then I went back to by 240VAC to 5V adapter and it stopped working again.

This time, I decided to power on the 240VAC to 5V for 10 seconds with the LM1117 connected (and ESP-01 with disconnected GND) and only after 10 seconds do I connect the ground pin from LM1117 to the ESP ground. This works 100% of the time.

I don't know what I could do yet, but I think I need to run a capacitor timer somewhere and let it run before connecting the ESP GND (or VCC?) to the LM1117 3.3V source.
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