Hello -
New to ESP & ESPHome, not new to hard and softwares
I’m trying to connect an LD2410 sensor to the KC868-A16 using the LD2410’s RX and TX pins. The documentation for the KC868 says to use GPIO13 & GPIO16.
I’m sure this is a stupid question - but where are these RX and TX pins on the KC868?
The diagram shows Digital inputs 1-16 as “dry contacts”. It also shows “GPIO’s 1->3” on the upper right of the board. I tried using Digital inputs (Dry contacts) 13 & 16, along with the configuration from the yaml sample file but I don’t get any comms from the LD2410. I also tried using the RS485 A & B pins connected to the RX and TX on the LD2410.
I’ve been trying for days - and just cannot get it to work. The LD2410 does work via bluetooth as well as the “OUT” pin - I just cannot figure out which pins on the KC868 to use.
I wonder what people are doing with these boards… Except frying their sensors.
Esp32 can mux rx/tx to any Gpio, that’s not a problem. Just to find a pin that is not pulled up/down to 12V or optoisolated.
Try 32/33 (or 4/5 if you don’t use I2C)
That board is a monster. All the inputs are optoisolated and pulled up to 12V.
Outputs seam to go through transistors and rx/tx are through RS485 converter.
Not a lot left for normal use…
Ok - THANKS for the replies and link to the Pinout Reference - I went down a nice rabbit hole and read thru a lot of the related links as well as most of the ESPHome Getting Started content.
Based on my new knowledge, I understand that the 32 inputs and outputs on the KC868 are from port expanders via the I2C bus, hence my confusion as to why I didn’t see them defined as legit GPIOs in the yaml (keep me honest here).
My next bit of confusion came from the actual GPIO pins on the KC868 - I still couldn’t figure out the relationship between the “physical” pins and the “port” pins and for the life of me didn’t know how you (Karosm) knew which ones were which. I kept looking for some magical mapping graphic for the KC868 like the ones i’ve seen for various dev boards. Shit, I even tried superimposing one of those graphics over the photo of the KC868 thinking I could see a pattern lol… Now I know that there is no standard pinout that everyone follows and you simply looked at the pinout table for your recommendation or “menu” of options. As I understand from my reading, the mapping/placement from the ESP32 pins to the physical board is at the sole discretion of the board designer (again, plz keep me honest). And, the board designer can choose which GPIO pins they want to expose for their specific implementation - in this case it’s limited to the ones listed in the table on the product page.
And finally, to answer your question as to “what people are doing with these boards”, I’m migrating a bunch of hard-wired occupancy and other “dry contact” sensors from an 8-port Insteon I/O controller running on Indigo Domotics to HA & ESPHome via the KC868.
That’s why you have to be careful with this board. Those “dry contacts” are not so dry at all, they all have pullups to 12V. Enough to fry normal 3.3V sensors.
What about gpio 32/33, I think they might be direct. 4/5 are for sure.
Here’s an update, hopefully it can save someone some time in the future…
I gave up on this solution - using the kc868 to connect to about a dozen LD2410 presence sensors .
Why?
It’s my fault entirely - I’ll chalk it up as a learning experience.
When I bought the KC868, I ignored the “dry contact” description for the 16 inputs - and assumed I could just update them to do what I wanted as if they were standard GPIOs. Clearly NOT the case.
I wasted a ton of time just trying to get GPIOs figured-out for the comms between the LD and the KC868. I then wasted (a’hem, learning) another couple of nights trying to figure out how to get the OUT pin on the LD2410 to activate on one of the dry contacts - mainly by tweaking every possible setting on each of devices, all to no avail.
I then thought I could stick a small 3v relay connected to the LD2410, to close the circuit/dry contact - but the output didn’t have the amperage to close the coil in the relay - and I don’t think an SSD relay would’ve worked b/c there was no load that would be going across it. I started going down the MOSFET route and finally decided that this just wasn’t worth it as I need to make about a dozen of these, and my goal is to design/print the smallest possible housing for an ultra-small ceiling mount.
TBH, I only bought the KC868 bc I thought it would save me a bunch of time NOT having to design a nice DIN-mountable housing for the ESP with the terminal screws and whatnot (mounted on a panel with all of my other HA components in the utility room). I really just need something with ethernet, a dozen inputs and about 2 outputs.
I have some Ethernet-based ESP32’s that I was able to get working immediately - so I just need to work on the housing. I’ll wait until the tariffs kick-in and stick the KC868 on eBay…
Making something like this was what I was trying to avoid by buying the kincony. In the end, I’m happy I made it, funny enough in a fraction of the time I spent trying to get the kincony to work. Will post the stl files after I add the cover. It mounts on a DIN rail.
.
