"Not so" Final board build and assembly #32

jazzmonger · 2023-02-28T05:32:51Z

jazzmonger
Feb 28, 2023
Maintainer

While this all sounds great...Practice proves otherwise. Problems w/ this design:

I'm pushing this little D1 to far....
the D1 is running out of memory! when that happens, lots of things can and will go wrong.
I mounted the D1 using the backside of the ant. unfortunately the way its positioned installed on the stove,the wifi signal sucks.
So, I've SUCCESSFULLY mounted and programmed a D1 on a daughter board without the Wifi Module. it required a level shifter, but its working.
next step in the saga is to convert the code to an ESP32-C3 which are on the slow boat from China. But I have a dev board, so I'm already working on that!

I'll leave this post here. Who knows, perhaps someone will someday find something useful in my failure? Much of the build pics are still relevant as are the mods to the main MCU board.

I have the final working product finished and all functions operational, at least on the bench. This really is a win in conquering this beast. Alas, to get the full functionality it requires removing the TYWE1S Tuya chip and replacing it with a D1 mini, but that little chip seems more than capable of running all the functions that make this pellet stove truly smart, and a joy to use. If the Tuya functions reported temps more than once every 60s, it would have been fine to keep the original chip.

But with the D1 mini, now we get an analog A0 port that measures the exhaust temps accurately and in near real time, and extra GPIOS that are used to measure the pellet level in the hopper and one GPIO I use to reset errors and get the stove working again without having to touch it or add a smart plug to turn it off and on. And a USB port 'just in case' we need it.

I took lots of pics along the way and I'll post them here in some type of order that hopefully makes sense. I used a hot glue gun to great effect in holding down the D1, usb jacks and even to organize the wires in some cases. Patience here pays off. You can't rush the cooling of hot glue.

The Home Assistant Lovelace Command Module. I can spend hours watching and tweaking all this shit. Who knew that pellet stoves have so many components that keep them lit and operational!

1- Female usb jacks used on both the display and the main MCU control board. Dremel the holes and hot glue them in. I then used an old micro to standard usb cable and cut the micro end off. Then added a standard male connector to that end of that cable. This gives me a standard male usb connector on each end to connect the main MCU board to the display board carrying the bi-directional auger signals and the analog thermocouple exhaust temp signal.

2

3 - Final assembled boards

4 - Bottom view of daughter card. D1 mini attached underneath the daughter board with hot glue. Notice the Level shifter under the wires - only one level shift is required and is used to apply 5v to the Thumbs Up button for 3 seconds from GPIO0 on the D1. This resets any errors that might appear on the stove without having to unplug or power it off/on. I added that 3 row of cut diy circuit board to give the large jack more stability. The use of these jacks are just me being anal and having fun buying shit on AliExpress. You could totally do all this without jacks. That's how I did my prototype and it works fine.

5 - Top view of daughter card. Only 2 conns required to where the TYWE1S chip was. RX & TX, that's it. I take a ground off one leg of the little switch. +5v is taken just above the rx/tx wires. This is before adding the jack for the Ultrasonic Sensor.

6 - Adding the 4 wire Ultrasonic Sensor jack. +5v, gnd, echo and trigger. Removing the old Tuya chip gives plenty of room for all this stuff!

7 - Ultra low power level light indicator stolen from the useless timer function.

8 - tapping the rightmost (TX) pin of the data interconnect cable gives us a tap on the UART signals from the display so we can decode the display messages and echo them in home assistant Lovelace.