- Sat Apr 28, 2018 11:31 pm
#75667
So, as schufti suggested, since you have no voltage regulation a Li-Ion will supply up to 4.2v directly to Vcc and damage your esp8266. Am I missing something?
- Sun Apr 29, 2018 1:41 am
#75668
How are they connected? The reason I asked for a picture is to how you are doing this. A schematic is a connection list and only tells a part of the story. You may be doing everything right according to a schematic but it may not be adequate for operation.
Maria Sierra wrote:VCC and GND are connected to the lithium battery with a capacitor of 22 µF
How are they connected? The reason I asked for a picture is to how you are doing this. A schematic is a connection list and only tells a part of the story. You may be doing everything right according to a schematic but it may not be adequate for operation.
- Sun Apr 29, 2018 3:27 am
#75669
Yes but why i connect it again with LiOn or FTDI USB (5V) it works again?
Concerning the picture, i will post asap when i come back.
Whatever, the capacitor is directly soldered on the ESP8266 (as close as possible) and the wires between ESP and battery are 10 cm long.
McChubby007 wrote:So, as schufti suggested, since you have no voltage regulation a Li-Ion will supply up to 4.2v directly to Vcc and damage your esp8266. Am I missing something?
Yes but why i connect it again with LiOn or FTDI USB (5V) it works again?
Concerning the picture, i will post asap when i come back.
Whatever, the capacitor is directly soldered on the ESP8266 (as close as possible) and the wires between ESP and battery are 10 cm long.
- Sun Apr 29, 2018 8:11 am
#75672
As I said in my first post.
I am going to numbers that are for this explanation and I am not saying that this is the exact voltages you have.
Let us say that the ESP8266 will fail (causes a stack error) if the voltage drops below 3.0 volts. Also let us say that the way you are powering the ESP-07 causes a instantaneous voltage drop of 0.4 volts.
When powered from 4.0 volts the 0.4 volt dip causes the ESP to see a minimum voltage of 3.6 volts. And since that is above the minimum 3.0 volts stated above, it continues to work.
When powered from 3.2 volts the 0.4 volt dip causes the ESP to see a minimum voltage of 2.8 volts. And this is below the minimum voltage the ESP needs, and therefore it crashes.
And that is part of your problem is. You used the right word, long. What you should have is short lengths.
And you should not be powering the ESP with more than 3.6 volts. The higher the voltage the greater the likelihood of permanent damage. In your case I think what is happening is the parts are drawing excessive current much of the time but when the ESP needs to draw a peak current, then the power supply voltage drop will help to minimize the potential damage. Use proper regulation!
The ESP8266 goes through a calibration procedure when it starts up. It will draw a high peak current at this time. If the power supply is incapable of supplying the required curren then it will fail. The power supply should be capable of supplying at least 400mA.
What is need in your case is a regulator that has a "low drop out voltage", 500mA current capacity, and low operating current. And you will need proper capacitors and have all this wired at the ESP module. Not 10 cm away. Short wires on everything. If you don't need the length then don't have it.
Maria Sierra wrote:Yes but why i connect it again with LiOn or FTDI USB (5V) it works again?
As I said in my first post.
At 4 volts the power dip is not below what the ESP8266 needs to operate. But at 3.2 volts the dip disrupts operation. The meter can't measure the sudden drop in voltage. You are seeing the average value with the meter.
I am going to numbers that are for this explanation and I am not saying that this is the exact voltages you have.
Let us say that the ESP8266 will fail (causes a stack error) if the voltage drops below 3.0 volts. Also let us say that the way you are powering the ESP-07 causes a instantaneous voltage drop of 0.4 volts.
When powered from 4.0 volts the 0.4 volt dip causes the ESP to see a minimum voltage of 3.6 volts. And since that is above the minimum 3.0 volts stated above, it continues to work.
When powered from 3.2 volts the 0.4 volt dip causes the ESP to see a minimum voltage of 2.8 volts. And this is below the minimum voltage the ESP needs, and therefore it crashes.
Maria Sierra wrote:wires between ESP and battery are 10 cm long
And that is part of your problem is. You used the right word, long. What you should have is short lengths.
And you should not be powering the ESP with more than 3.6 volts. The higher the voltage the greater the likelihood of permanent damage. In your case I think what is happening is the parts are drawing excessive current much of the time but when the ESP needs to draw a peak current, then the power supply voltage drop will help to minimize the potential damage. Use proper regulation!
The ESP8266 goes through a calibration procedure when it starts up. It will draw a high peak current at this time. If the power supply is incapable of supplying the required curren then it will fail. The power supply should be capable of supplying at least 400mA.
What is need in your case is a regulator that has a "low drop out voltage", 500mA current capacity, and low operating current. And you will need proper capacitors and have all this wired at the ESP module. Not 10 cm away. Short wires on everything. If you don't need the length then don't have it.
