Ok loopback test is working fine. Verified that TX/RX pins on the Feather map to GPIO16 and 17. I also ran the loopback through level shifter and it’s working fine there too. Not sure what the problem is at this point. I ordered an oscilloscope from Amazon and it should be here tomorrow.
Ok it works! Turns out the issue was the Adafruit TXB0104 based level shifter I was using. Either they were defective (I tried two!) or they don’t work for this application for reasons I don’t understand yet. I actually needed to buy an oscilloscope to figure this out. Fortunately I was able to pick up a Sparkfun converter at Microcenter and it works like a charm. So just some caution for anyone who used the Adafruit converter and ends up having the same problem.
2 Likes
If your time permits, you could ask Adafruit for a statement? It would be interesting to know why this level shifter isn’t working as expected. 
But it’s nice to see, how you figured it out (I followed your experiments on Telegram). 
The display is extremely bright and annoying, so we still need the remote on our nightstand to turn it off. Or we have to disable the display more permanently 
Would it be possible to use the ESP to send the IR code to disable the display, by connecting an IR LED to it and point towards the IR receiver internally? Did anyone manage to decipher the IR data yet?
So far it seems the display dimmer is IR only and not t controllable over uart.
Some people have started developing it, but not sure what the status is…
Yes that is possible. I made a dongle using a Wemos D1 with an IR Led.
On this photo the Wemos is not soldered in place yet:
This is my config:
esphome:
name: esp_hvac_skr
platform: ESP8266
board: nodemcuv2
wifi:
ssid: "xxxxxxxxxxxxxx"
password: "xxxxxxxxxx"
ap:
ssid: "xxxxxxxxxxxxxx"
password: "xxxxxxxxxxxxx"
captive_portal:
# Enable logging
logger:
baud_rate: 0
api:
ota:
uart:
tx_pin: TX
rx_pin: RX
baud_rate: 9600
midea_dongle:
climate:
- platform: midea_ac
name: "Slaapkamer"
beeper: false
remote_transmitter:
pin: D7
carrier_duty_percent: 50%
switch:
- platform: template
name: "Display toggle"
turn_on_action:
- remote_transmitter.transmit_raw:
carrier_frequency: 38kHz
code: [ 4390, -4371, 572, -1573, 548, -525, 570, -1575, 547, -1598, 547, -525, 573, -1570, 574, -500, 547, -1598, 551, -520, 549, -1597, 572, -498, 549, -524, 547, -1597, 572, -500, 550, -1596, 571, -500, 574, -1571, 572, -1574, 548, -1597, 546,
-1598, 548, -523, 549, -1596, 572, -499, 573, -1571, 573, -500, 570, -501, 548, -524, 573, -500, 572, -1572, 548, -524, 549, -1597, 547, -523, 572, -1573, 572, -499, 548, -1596, 550, -522, 578, -495, 548, -1596, 571, -499, 549, -1598, 548, -523, 549,
-1595, 571, -500, 549, -1596, 548, -1597, 548, -523, 574, -1571, 549, -523, 572, -5157, 4390, -4368, 548, -1596, 550, -521, 574, -1571, 572, -1573, 547, -525, 548, -1595, 549, -523, 550, -1594, 549, -524, 549, -1595, 548, -523, 550, -523, 548, -1596,
548, -523, 550, -1595, 547, -524, 549, -1595, 549, -1595, 550, -1595, 549, -1598, 546, -524, 548, -1595, 549, -523, 548, -1598, 547, -522, 550, -523, 551, -520, 550, -522, 550, -1595, 549, -522, 551, -1596, 572, -499, 547, -1596, 548, -524, 549, -1596,
548, -523, 550, -523, 571, -1574, 547, -523, 549, -1596, 548, -523, 549, -1597, 547, -523, 550, -1594, 574, -1572, 549, -522, 549, -1596, 549, -522, 550]
3 Likes
Cool Noël! Many thanks.
Been lurking other forums but did not find a proper solution yet. Time to order a IR LED and check this out 
You’re welcome! You’ll also need a transistor and a resistor. I used the diagram from this page:
I did not add the IR Receiver to my dongle, but a receiver can be useful for sniffing IR commands from the remote.
Hi, I assumed a transistor was necessary, so thanks for the schematics. Just dismantled an old IR blaster so I don’t need to order a LED. I must have some transistors lying around also, not the one mentioned in the linked GitHub page, but a simple BC547B should do the trick also. And otherwise I’ll just dismantle an old IR remote, there should be a suitable IR LED and transistor to salvage from that.
I used a BC549C, also works fine
Finally found some time to integrate the IR LED and control the display, works fine. It didn’t work with your raw codes, probably a different model/brand AC, so I had to read the codes with an IR receiver.
I was wondering if anyone found a way to control the fan speed, can’t seem to find it in the esphome component itself or on this (or other) forum. I should probably be able to control it with the IR integration, but would be nice to also have feedback on it over the uart.
EDIT: oops never mind, reloaded the device and fan mode and swing mode are back in the hvac entity
So, I’m completely new to this Topic and haven’t read through all 156 comments to be honest. (I actually did now )…
I Have a “Dimstal SMND-12ECO” AC which, as far as I could find out, is pretty much identical with midea…
Still, the midea_ac component doesn’t seem to work properly 
What I did:
- flashed an ESP-01 via the ESPhome addon, using this yaml:
(no errors or warnings)
esphome:
name: ac01-esphome
platform: ESP8266
board: esp01_1m
wifi:
ssid: !secret wifi_ssid
password: !secret wifi_pass
# Enable fallback hotspot (captive portal) in case wifi connection fails
ap:
ssid: "Ac01-Esphome Fallback Hotspot"
password: "***"
captive_portal:
# Enable Home Assistant API
api:
password: !secret api_ota_pass
ota:
password: !secret api_ota_pass
# Disable logging over UART
logger:
baud_rate: 0
uart:
tx_pin: 1
rx_pin: 3
baud_rate: 9600
midea_dongle:
strength_icon: true
climate:
- platform: midea_ac
name: "My Midea AC"
visual:
min_temperature: 16 °C
max_temperature: 30 °C
temperature_step: 1 °C
beeper: true
swing_horizontal: true
outdoor_temperature:
name: "Temp"
power_usage:
name: "Power"
humidity_setpoint:
name: "Hum"
- used the adapter to connect it to the AC:
the Logs now show this:
usually it just shows gibberish (as far as I’m concerned) and only shows readable values, if I send a command with the original IR remote control (like here)… also there’s that occasional yellow “RX: frame has unknown type” warning
What could I have done wrong?
EDIT:
The AC doesn’t do anything when I try to send a command via Home Assistant - the climate Lovelace card shows unavailable and if I try do select something there (for example a different fan speed) it just goes blank a second later
EDIT2:
the AC is Wifi enabled - it was sold as such and there was a “USB” plug connected where the ESP-01 is now
EDIT3:
tried “esphome_version: esphome:dev” … no change
EDIT4: I doubt I need a logic level converter, since that’s what the adapter seems to do already - TX and RX to ground are almost 5V …
EDIT5:
It works now … I deletet everything from ESPhome and Home Assistant, re-flashed the ESP-01 and addet it again… I have absolutely no idea what is different now, since the configuration is exactly the same as before (except for the name)
1 Like
Your circuit board looks exactly the same as mine and has the same part-No - is that a Dimstal AC?!
So you use a logic level shifter?! I assume you have tried without?!
Did you have to do any special steps setting everything up?
Have you tried switching the brown and yellow duponts on the esp side (RX and TX)?
Yes I did that - the result is like that: Support for Midea A/C - #138 by BakaMonogatari
so there’s only “one” TX line and IR commands are not showing up.
At least I get TX and RX, which should mean, that it’s connected correctly 
Not that I look you noob (I’m not), but do you have connection between your ESP and your wifi network? (check your router log and ensure that the ESP is connected).
Also, have a try with the recommended settings (ie no !secret yaml, enter the wifi password directly into the esphome yaml). Also: have you set password for homeassistant api? If so, then disable it until you’re 100% sure that it’s not the root cause.
You absolutely should! xD
It has to be connected to show the log, doesn’t it?! 
Also it shows up in my router’s device list, and it is online (green) in the ESPhome Addon
I’ll try that
EDIT: no change … still just
[10:55:55][D][midea_dongle:094]: TX: AA 22 AC 00 00 00 00 00 03 03 41 00 00 FF 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 84 68
[10:55:56][D][midea_dongle:029]: RX: AA 22 AC 00 00 00 00 00 03 03 C0 01 4B 28 7F 7F 00 30 00 00 00 64 65 00 00 00 00 00 00 00 00 00 00 E7 1A
[10:55:56][D][midea_ac:034]: RX: query frame
[10:55:56][D][midea_ac:072]: TX: query
over and over again
with switched RX/TX cables as well?
If I switch the cables it’s:
[11:05:16][D][midea_dongle:094]: TX: AA 22 AC 00 00 00 00 00 03 03 41 00 00 FF 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 84 68
[11:05:17][D][midea_ac:072]: TX: query
[11:05:17][D][midea_dongle:094]: TX: AA 22 AC 00 00 00 00 00 03 03 41 00 00 FF 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 84 68
[11:05:18][D][midea_ac:072]: TX: query
[11:05:18][D][midea_dongle:094]: TX: AA 22 AC 00 00 00 00 00 03 03 41 00 00 FF 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 84 68
[11:05:19][D][midea_ac:072]: TX: query
[11:05:19][D][midea_dongle:094]: TX: AA 22 AC 00 00 00 00 00 03 03 41 00 00 FF 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 84 68
[11:05:20][D][midea_ac:072]: TX: query
I think this one should be working. Try this: OTA update your device via ESPHome and check carefully your log. It should show that it’s connected to Home Assistant.