Connecting the PLCDuino to Cayenne


Looks like that the zeners will clamp regardless what packs you install. I reinstalled the originals. The lcd reads accurately now but the reading on the dashboard higher. 9.23v = 46.14 on the dashboard / by 5 = 9.238. The voltage level reads correctly on the dashboard if I choose float, I can live with that. Maybe it would be best to just instal voltage dividers at the analog inputs that equal 0-60v = 0 -10v, what you think, simpler solution?

I would like to figure a way to use 1 meg packs but that will have to wait while I grow the sketch using your example to use all the analog inputs as voltage inputs. The digital inputs are a cinch because as I found that cayenne handles the gpio without code if you just need a 2 state reading like say “Solar Rpi online”. That should be easy just having a gpio go high whenever its up and running. Many have noticed that their gpio’s are going high on reboot and suspect it’s because they are inverting state for that actuator.

Have you figured out what you want to do with your plduino? I almost bought a pellet smoker the other day and thought another plduino set up in the outdoor storage with a cable running to the smoker or an outlet receptacle mounted on the outside wall.Hacking hardware is fun. I have an indoor wind chime using a wemos d1.





The zeners shouldn’t clamp if you just replaced RN1 with the 1Meg packs.

For you, you will want to replace:

float adcVoltage = 10.0*adcVal/1024;


float adcVoltage = 55.0*adcVal/1024;

If you used my sketch, the two numbers should be the same in Cayenne and on the display, save a significant digit or two.

I will probably use my PLCduino to control a home brewery eventually, although, I like having distributed controls, so may just use ESPs.




Me again! ,

I got thru adding A1 to the code, this is getting a little easier each time. The voltages on the lcd jump back and forth on their own block of yellow, let’s see if I’m right (pos x, pos y, size x, size y)??




(top left x, top left y, width, height), but note that the display is 240 wide by 320 high, so it is mounted in the PLCDuino on it’s side :slight_smile:

Here is a good sketch for figuring out how to manage positions on the PLCDuino display:




So, I’m very excited that I finally got my plduino to connect via wifi. Unfortunately it will only connect if I use my cell phone as a mobile hot spot. I can’t get it to connect to my Google On Hub Router. Any thoughts? I have searched and searched and have found no definite answers. Some think it has to do with the dhcp. Or the type of mode the ESP is in. Client, Server, or Both. I couldn’t find where this can be changed in the code. Or if it has to be changed in one of the library files.


I’ve never used, or heard of, OnHub Router but a quick google search suggests it’s a standard router and should work fine. I kind of wonder if they patched the recent wifi vulnerability and it’s affecting your ESP? I’m honestly not too sure what’s involved in the patch. This link here suggests it has not been patched so might be pointing you in a wrong direction. Can you check if you have any updates past June? Another step I have to ask is to check to see if you have any other devices that can connect.


I have 13 other devices connected to the router. None are esp’s. My router did update in the last 10 days. So maybe it has something to do with the wifi vulnerability. That would be my luck. I’m sure I will figure it out eventually. Just funny that I can get my mobile hot spot to connect and not the on hub router.


@kreggly has some security connections, maybe he would know if the patch affects esp’s? I’ll read up on it tomorrow to see what I can find. The minimum reading I did tonight suggests you can patch the client or the access point which would make me think it isn’t a problem. One other suggestion I have is to delete whatever you have in the ssid and password variables in your sketch and type them again. I’ve made spelling errors on that too many times to count.


It’s got to be port blocking. Cayenne needs 1883 open. Move your ESP IP to
the DMZ zone in router config and see if it works.

If so, you need to figure out how to create firewall rules.




Sometimes you feel stupid, Apparently my wifi hotspot from my phone is not case sensitive to the SSID. However, the On Hub is. I’m all connected now. Thank you all for the help. So happy that I have my PLDUINO connected. Now for the rest of the project.


Groovy tunes.

Whatcha building?


Controlling a greenhouse for super hot peppers. Being able to know the
hydroponics system is working.