Lesson28- How to use KC868-A4 (ESP32) DAC output DC 0-10V by ESPHome

[admin]

esphome:
  name: kc868-a4
  platform: ESP32
  board: esp32dev
 
output:
  - platform: esp32_dac
    pin: GPIO25
    id: dac_output2
  - platform: esp32_dac
    pin: GPIO26
    id: dac_output1

light:
  - platform: monochromatic
    output: dac_output1
    name: "KC868-A4-DAC1"
    gamma_correct: 2
    id: dac_light1
  - platform: monochromatic
    output: dac_output2
    name: "KC868-A4-DAC2"
    id: dac_light2

# Enable logging
logger:

# Enable Home Assistant API
api:

ota:
  password: "3b853165e19b67ba8193c59fe59f21a7"

wifi:
  ssid: "KinCony"
  password: "a12345678"

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "Kc868-A4 Fallback Hotspot"
    password: "RgIGz8qo4bVC"

captive_portal:

[Tomek]

Hi Admins,
I use KC868-A4 with esphome.
I have problem with DAC output, in my case is to low. Max i have 9.45V. But i need 9.8V minimum. What i can do in my problem

[admin]

what's your power supply voltage?

[Tomek]

what's your power supply voltage?

DC 12V 2A with voltage adjust. Now i set 12,3V but it did nothing. I tried two other power supplies (DC 12V 5A, and 1,67A), same result.

[Tomek]

So any idea? Why can't get 10V ?
On your video about DAC is 9,5V. It's max?

[admin]

1. you can check your PCB 3.3v Vcc pin whether is well. whether it's 3.3v value.
now R37,R38,R47,R49 all are 10K resistance.
if use 20K resistance , MAX DAC voltage should be: 3.3v * (1 + 20K/10K) = 9.9V
2. if Vcc is 3.3v work well , you can try to replace 20K resistance to 22K for a test. it should be output MAX 10.05V

[bas_vdl]

So any idea? Why can't get 10V ?
On your video about DAC is 9,5V. It's max?

Were you able to solve it? I'm looking into this board to control my gas fireplace which needs 0v (off) and 10v (2 burners, high flames).

Thanks!

---

1. you can check your PCB 3.3v Vcc pin whether is well. whether it's 3.3v value.
now R37,R38,R47,R49 all are 10K resistance.
if use 20K resistance , MAX DAC voltage should be: 3.3v * (1 + 20K/10K) = 9.9V
2. if Vcc is 3.3v work well , you can try to replace 20K resistance to 22K for a test.  it should be output MAX 10.05V

Hi, I have a couple of questions, hope you find the time.

Which is one the Vcc pin?

And where i should put the 20k or 22k resistance?

And will it also be able to produce 0V?

Thanks!

[admin]

Which is one the Vcc pin? that is 5V , see text on the PCB.

And where i should put the 20k or 22k resistance? R37,R38,R47,R49

[rtoivo]

I'm using node red in home assistant.
I have tried several various ways to control DAC (percentage value) from node red without success. 
Output is working fine in lovelace.
Could you show an example how control should be done in node red?

[admin]

which board you are using? if use KC868-A4 board, i think you can download "KCS" v2 firmware, then integrate to Node-Red by MQTT.