Anybody use DMX on Kincony A24's RS485 on EspHome in Home Assistant?

[KRende]

Good day.  Has anybody set up DMX on Kincony A24's RS485 in EspHome in Home Assistant?  I tried installing the Github add-in at https://github.com/andyboeh/esphome-dmx512, but I'm a beginner and haven't gotten it to work so far.  The Kincony's input and outputs work fine, but I don't know how to proceed.  I've put this in the Kincony's Yaml file, and the logger reports the value being sent to DMX_1, but my fixture's DMX indicator doesn't come on, so I don't even know if I wired it correctly.  Anyway, here are the Yaml settings:

uart:
  id: uart_bus
  tx_pin:
    number: 33
    allow_other_uses: true # For ESPHome >= 2023.12.0
  baud_rate: 250000
  stop_bits: 2

dmx512:
  id: dmx
  uart_id: uart_bus
  tx_pin:
    number: 33
    allow_other_uses: true # For ESPHome >= 2023.12.0
  uart_num: 1
  periodic_update: true
  update_interval: 500

output:
  - platform: dmx512
    channel: 1
    universe: dmx
    id: dmx_1

light:
  - platform: monochromatic
    name: "Test Lights"
    output: dmx_7
    id: light_test
    default_transition_length: 2s

[admin]

which DMX512 controller you are using? can you take a photo.

[KRende]

which DMX512 controller you are using? can you take a photo.

I want to use the Kincony A24 as the controller, so it needs to transmit.

[defl]

Hey KRende, I just ran into the exact same as you using ESPHome for DMX. I've bought a few A6'es for this and gave them a quick spin only to discover there is no output.

When looking at the design documents (https://www.kincony.com/kc868-a6-hardwar...tails.html) and the datasheet it lists the MAX13487 chip being used for this (which is great and I've used it before). However in reality it comes with a MS2548, which is listed as a drop in replacement, but when you look for it there are plenty of posts where this was done leading to issues. (https://electronics.stackexchange.com/qu...ounterfeit for example). Going by the schematic from Kincony their design looks a lot like others (VCC to /RE and /SHDN) but I didn't validate yet. Unfortunately I have no other working MS2548 boards to compare to.

When I scope out the TX pin on the ESP32 with the ESPHome code roughly as above that works, and I get a clean DMX pattern. Nothing after the MS2548 as observed above.

@admin: Can you provide a code example which I can run to validate the hardware actually works?

[admin]

MS2548 as same as MAX13487, just MS2548 made in China.

[defl]

MS2548 as same as MAX13487, just MS2548 made in China.

Well, that would mean the A6 I got is broken as there is clearly input into the chip and no output. On the other hand, there are a few reports of these chips not doing what one would expect. So would you happen to have some example code that I can run which will generate a valid RS485 output to confirm all is well and the error is mine?

[admin]

https://www.kincony.com/forum/showthread.php?tid=1867

[defl]

So I finally got around to spending an hour on this. My test setup is the AB and of the RS485 are connected to DMX+ and - respectively of an Eldoled Linear 100 driver, terminated with 120ohm at the driver. The board ground is connected to the driver DMX ground. The scope is a cheapy Hantek so I don't trust it too much in terms of absolute levels.

The link is probed with two floating probes connected to the busses and in the scope the math is A-B. A is clearly the original and B the inverted, however the waveform that comes out deserves no prizes, the inverted side is significantly different in voltage level than the positive, resulting in a skewed signal (A is 1.1v p2p, B is 2.5 p2p). The final combined output signal is 2.8v p2p.

Long story short, I got this working a few times but the driver simply doesn't like the signal coming out at all. It worked a few times with a really short wire and no termination resistor, though I can't see the difference between with or without on the scope.

Time to get myself some better measurement tooling and a genuine MAX13487 and try again.

If I could upload images I would throw in a screenshot.

[defl]

Dug into this and solved it, turned out the ESPHome config is finicky in ways I didn't expect. https://github.com/andyboeh/esphome-dmx512/issues/40