Hi I am having trouble uploading a sketch to the ESP8266, all connections and voltages are correct except for an incorrect voltage on GPIO00 equal to 1.56V even though this pin is connected to 3.3V through a 10K resistor, the problem It seems to me that it is this voltage, I don't understand why it is the ESP8266 throws it at 1.56V when it should be at 3.3V, someone has experienced the same thing?
I cannot properly answer that with the information give. You could have a bad ESP8266. Is it possible the pin has a clock or PWM signal on it? Are you sure the resistor in connected properly? GPOO00 is a general usage port so unless there is code running I would guess a bad ESP8266. Do you have another to try it?
I have already changed the ESP8266, also the flash memory, the transistors that make the switching of the RESET and Boot and the FT232R, I don't understand what could be happening,
"ESP8266", in this context, is, in a way. . . meaningless.
Is this an ESP-01 or a NodeMCU or some other Dev Board?
Can you be specific?
If you're doing with ESP-01, buying one of these eliminates a lot of screwing around --
You need to provide:
1: a schematic
2: a link to any/all parts you are using
3 : your code
I am using the same ESP8266EX microcontroller, taking as reference several designs that are spread out there, my problem is I cannot enter the serial bootloader mode, here is my schematic.
Error serial bootloader mode.pdf (23.0 KB)
Looks like a hardware problem.
If you had a board made and populated, perhaps is it defective or wrong.
No, the board is well designed and manufactured
If you remove Q6, does GPIO00 go to 3.3V ?
Or is there any voltage at its base?
But it doesn't work. Have fun with your project!
jremington, I think you misunderstood me, I meant that the PCB and are well manufactured, the error is in the design, something that I am omitting or something that is wrongly connected in the schematic
And you should be looking at the automatic Reset/Boot mode system. as ZX80 is also suspecting in reply #10.
To confirm that you could remove Q6 altogether and check the voltage which then should read 3.3v.
I suspect there is some kind of signal coming in through the DTR, but just measuring the voltage is not a very accurate way of trying to find what is going on. You need a scope, because i seriously doubt that the measured 1.56v is actually a constant voltage.
Well yes, but what is running now on the ESP ? what is in the flash ? it is quite possible that the GPIO is fluctuating in voltage because the Flash is uninitialized.
Again the only way to confirm that is to remove Q6 and check what is happening.
And that is what has gone wrong. The normal procedure is to first create a prototype which you populate part by part and check functionality. Normally speaking i would first make sure i have the manual reset working and boot-mode selection working properly, just to confirm that i have a working combination of MCU & flash memory.
Anyway i think you will understand how to approach this. Just the ESP & flash, use a separate USB uploader that is known to work. Then start adding stuff. If you are suspicious of some parts, you will just have to disable their function and replace them with parts that are known to work. If you have multiple possibilities of problems you will be searching in the dark.
Is there a way to invert the transistor pins that would give that result ?
This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.