2 WEMOS D1 on the network and it causes chaos

Hi Guys,

Got something weird going on here. I made a project back in Jan19 using a wemos D1 on wifi for a PWM dimmer via a blynk slider and alexa. It has worked a treat faultless since day 1, until I made another project. 4 way wifi loudspeaker switch with 4 push buttons and blynk buttons to select each speakler pair, with a Wemos mini d1, on wifi, using the same network. I built this and tested it at work on a different network and it works perfectly, again faultless. So I took it home and connected it to my network with PWM dimmer - at that point both wemos boards just went crazy, connecting and disconnecting all the time, to the point were both were useless.

so I then removed the 4 way spkr switch(powered off etc) and the PWM dimmer now refuses to connect at all. I have brought the PWM dimmer to work and connected to network here and again it works fine!!! its just when I hang both of them on the same network. I did note the both had different IPs

anyone any ideas what is going on here ???



Are you using different Blynk Auth codes, or sharing one code?

Have you tried rebooting your router and any switches/access points on your home network?

Do you have any static IPs set-up in your router for these devices?


Hi Pete,

yes both got separate auth codes. rebooted everything. No static IPs both using DHCP
even deleted all the dvices connhected from the router DHCP table to force new IPs and they still went crazy!!



Are these D1 R1s, D1 R2’s or D1 Minis?

Do you have a third device that you could try with this code?

I use a collection of D1 Minis on my network without any problems, but I recently had one device that misbehaved. Sometimes it wouldn’t connect to Wi-Fi and other times it seemed to cause issues when it was connected. In the end it went in the bin.

I also had lots of network issues a while ago with things keep connecting and disconnecting and it took ages to get to the bottom of it. In the end I decided to check every device on the network and disconnect them one at a time to see if they were causing the issue. I scanned my network using Advanced IP scanner and worked my way through the list of devices without any joy. I then remembered that I had a wireless access point in my garden shed that hadn’t appeared in the list of devices. As soon as I unplugged it everything went back to normal, so it’s not beyond the bounds of possibility that one rogue device could be causing network issues.


I may have another device - I will check. one question is what happens when one of these devices is on the limit of wifi range??. Reason I ask is the 4way switch is in my shed and the other device is right next to the wifi router.

Could this cause issues with other devices - I hope it shouldnt!!

You might get disconnections and re-connections if you’re on the Kim it of the range, but why not bring it indoors and test it near the router to rule that out?

You can also add a timer to your code to take RSSI signal strength readings every 5-10 seconds and push these up to Blynk so that they are viewable in the app if you wish, to get an idea of what sort of RSSI values you’re getting.

At our place in Spain I have a couple of Sonoff Basics that still seem to keep working well even though they have RSSI values in the high -80’s and low to mid -90s…


Hi Pete not easy to bring it in as it has 20 wires coming out of it for all the inputs and outputs!! so bit of a pain.

Do you have example code to get the RSSI values - didnt know you could do that.
Also what values would you need to get for it not to work ?



You can do:

long rssi = WiFi.RSSI();

but …


may also work.

Acceptable Signal Strengths

Signal Strength TL;DR Required for
-30 dBm Amazing Max achievable signal strength. The client can only be a few feet from the AP to achieve this. Not typical or desirable in the real world. N/A
-67 dBm Very Good Minimum signal strength for applications that require very reliable, timely delivery of data packets. VoIP/VoWiFi, streaming video
-70 dBm Okay Minimum signal strength for reliable packet delivery. Email, web
-80 dBm Not Good Minimum signal strength for basic connectivity. Packet delivery may be unreliable. N/A



Cheers Pete will give it a try

Might be a stupid idea, but do you mind checking the MAC address of those Wemos devices? It could be that are the same :thinking: and if that’s true they will never work on the same network