I let the smoke out
I think RxTx serial communications are going to be my downfall. I made an oopsie.
Yesterday I took another look at the communications between the Uno and the NodeMCU, wanting to take the time to make sure all the buffers are of the appropriate size. Unfortunately the way Serial communications were created you can’t use your RxTx pins… or even have them connected, if you intend to upload an updated program to either of the computers. The constant needing to get up to unhook 2 wires, sit, upload new program, stand to connect 2 wires, sit to check results and recode what needs recoding…stand to unplug 2 wires… etc strips all enjoyment and sense of making any progress from the job… all it does is make me feel like I’m jumping through hoops in lieu of actually accomplishing anything.
Case and point, I was getting tired, a little bleary eyed and maybe a little annoyed at the flurry of standing and sitting I needed to do every 2 minutes and only was only getting errors for my efforts. I wasn’t aware at the time that I had connected the RxTx lines from the NodeMCU to the i2C lines out of the Arduino which prevented communication for obvious reasons.
In an effort to trouble shoot the problem I moved the dht sensor to a new position on the protoboard I was using, and swapped out the jumpers I was using to connect it… and in doing so accidentally reversed the 5v and ground lines. Unfortunately, I wasn’t aware of what I had done until it was too late. I didn’t see the smoke, but I could smell it… and you know what they say: Electronics require smoke to work, and if you let the smoke out of your device its going to stop working - Case and point, I haven’t been able to get any love out of my dht sensor since smelling it’s displeasure about what I had done..
As much as this sucks, there are a couple of silver linings that gave come into play as a result.
First: I wanted to pick up more DHTs anyways (to get a better scan of my room’s ambient temperature/humidity using multiple points of reference) so I ordered myself a pack of 5.
Second: While ordering DHTs I also went looking for some soil moisture sensors. I’d thought I might have had one stashed away, as I am thinking that it would probably be handy as part of a “sensor pack” (that includes temperature, humidity and light) I can leave in the garden. Happily, I found something even better. It was a 4pack of the soil sensors I wanted, that included a relay and 4 small pumps. Not only will these pumps allow me to start running multiple beds and reservoirs, I’ll be able to control their irrigation with the Colonel. My mind was blown when I saw that one, let me tell you! I am so looking forward to playing with these!
Third: While I was fiddling around, connecting and disconnecting the RxTx wires, I was alerted to a problem with my circuit - I have a leak. I noticed that while the NodeMCU was powered that the TDS sensor that is attached to the (unpowered) Uno would light up. This means that the sensor was drawing voltage backwards out of the “Voltage In” pin that shares the circuit with the small communication board I set up. I think I’m going to need to slap in another one of those diode thingers in there to prevent the backflow through the circuit.
Fourth: I just tried out a small tutorial sketch for i2c communications, and successfully handed test data off from the Arduino to the NodeMCU, when the Node requested it. That is a lot more in line with how I wanted the system to work both from both a technical (data management) and physical (not having to play with wires to test an upgrade) perspective. I am beyond motivated to upgrade the Colonel’s communications protocol to i2c as you can update/upload your programs on the fly, without needing to disconnect anything first. YES PLEASE!!
Fifth: Perfect world, The colonel should be using the clock/calendar chip to schedule tasks and automate processes to better control my data uploads instead of spamming them off every 10 seconds. As the Clock / calendar chip is also i2c, any “slave” Arduino on the circuit will also be able to benefit from clock access, should it be required.
With all that going on, plus the new case, plus the LCD screen, I think I’ll be more than justified in slapping a 2.0 on the Colonel’s designation when I’m done.
I’m looking forward to that!
