Nodo-shop OTGW and nodemcu restarts

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Nodo-shop OTGW and nodemcu restarts

Postby pawel5870 » Wed Mar 07, 2018 7:39 pm

I have a problem with restart when I'm connect nodemcu (esp-link) to otgw.

First I though that my power supply is wrong 24v/1A, so I changed it to 24v/1.5A, but result was the same.

When I connect only 5v & GND from OTGW and RX & TX (cables from nodemcu to pins on OTGW dedicated for nodemcu) it works without restarts.

Does any one had similar problem? There are other pins on board for example for powering display, but I have nothing connect to them.
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Re: Nodo-shop OTGW and nodemcu restarts

Postby daveh » Fri Mar 16, 2018 11:01 pm

yes i have the same problem.
Also powering with 24v.
The voltage regulator gets to hot to touch.
I wonder if 24v is too much ?
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Re: Nodo-shop OTGW and nodemcu restarts

Postby hvxl » Sat Mar 17, 2018 12:25 am

To my knowledge, the gateway sold by the Nodo shop uses a buck converter. That should not be dissipating much heat and so shouldn't be getting hot at all.
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Re: Nodo-shop OTGW and nodemcu restarts

Postby hvxl » Sat Mar 17, 2018 1:03 am

pawel5870 wrote:When I connect only 5v & GND from OTGW and RX & TX (cables from nodemcu to pins on OTGW dedicated for nodemcu) it works without restarts.

Your description is not very clear. What is restarting? The OTGW or the NodeMCU? If it's the gateway, please check the reason for the reset via the PR=Q command.
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Re: Nodo-shop OTGW and nodemcu restarts

Postby daveh » Sat Mar 17, 2018 11:03 am

With a 24v power supply connect the nodemcu board restarts. My system is not yet connected to anything other than a PSU.
You can see the blue led on the nodemcu flash as if it just has had power removed and re applied.
I don't have an oscilloscope so can't see much.
I have not yet seen it have an uptime of more than 1 minute on the easesp status page.

The 17805 voltage regulator on my board gets too hot to touch after less than 5 minutes after being plugged in
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Re: Nodo-shop OTGW and nodemcu restarts

Postby hvxl » Sat Mar 17, 2018 2:02 pm

Something doesn't add up. The ESP Easy status page shows the uptime of the NodeMCU, not the OTGW. If an overheating voltage regulator causes the NodeMCU to reset, that suggests the NodeMCU is powered from that voltage regulator. But as far as I can tell, the 17805 is just a dissipating voltage regulator. You can't use such a regulator to power a NodeMCU along with the OTGW on an input voltage of 24V. I'm sure the guys at Nodo shop are aware of that, so they would not use such a voltage regulator in their product.

So please confirm what hardware you are using.
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Re: Nodo-shop OTGW and nodemcu restarts

Postby daveh » Sat Mar 17, 2018 2:14 pm

appologies my description of the parts is probably not great.
So far I havn't looked at anything other than the nodemcu status The unit is new was purchased on 28 of feb this year.
If the Nodemcu is removed from the board and powered via a known good 5v supply then the nodemcu is very stable, no reboots.
When the nodemcu is attached to the unit and powered via the 24V vin I see the behaviour described above.


The node MCU 5v Vin is powered from the out line on the 17805 as far as I can see. You can follow the trace by eye to the Vin on the nodemcu daughter board.
If its not using that voltage regulator where else is the 19-24Vin converted to 5v for the node mcu ?
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Re: Nodo-shop OTGW and nodemcu restarts

Postby hvxl » Sat Mar 17, 2018 3:06 pm

That is very strange. I guess Nodo shop may have decided to use the 17805 for their USB version, which is OK. But for the Wifi version I don't see how that can work. They used to provide a step-down (buck) converter, which doesn't dissipate all the excess power. I suggest you contact Nodo shop support for an explanation.
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Re: Nodo-shop OTGW and nodemcu restarts

Postby daveh » Sat Mar 17, 2018 7:03 pm

so further pocking an it gets even stranger.
If the nodemcu is removed then the power regulator doesn't get warm at all.
It also doesn't vissable spark when power is plugged in. I might have to try an ammeter and see what current is getting pulled
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Re: Nodo-shop OTGW and nodemcu restarts

Postby hvxl » Sat Mar 17, 2018 9:28 pm

That's not strange. This was the original design of the OTGW, which was possible because the OTGW doesn't use much power from the 5V supply. This is why I mentioned that it's OK to use it this way with a USB cable. But the NodeMCU uses several 100's mA when WiFi is active. That means that a dissipating voltage regulator has to convert 2W or more into heat. Without a proper heat sink that will cause it to get hot. Then again, a few 100 mA is not that much that it will cause sparks.

Have you contacted the Nodo shop as I suggested? I really think that's the best way forward for you at this point.
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Re: Nodo-shop OTGW and nodemcu restarts

Postby daveh » Sat Mar 17, 2018 10:27 pm

I have now thanks for the suggestion Ill feed back what they say.
Thanks for the help :)
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