This is a implementation of the BenQ RS232 protocol for Home Assistant using ESPHome. It will read out different data and is also able to read and write settings from and to the projector.
All values and functionality is based on the manual of the projector BenQ W2700 and BenQ HT3550 for the RS232 connection.

How am I using this:

I am using this in my home cinema as the startup and shutdown is fully automated. The ESP is getting its power by the projector USB ports. As those are not powered during standby I adjusted the settings in the BenQ to startup the projector at the moment it is powered up by a switchable socket. After a few seconds the ESP is online and transferred the data into Home Assistant. The BenQ W2700 is a DLP projector, it should get a bit of cool down time after usage. So to shut everything off properly I am using an automation to put the projector into standby by RS232 with the ESP. At the moment the cool down has finished, the projector also shuts off its USB power, so I got my last needed trigger to switch my socket off when the ESP went offline.

What you need to do this:

• ESP (i had used a Wemos D1 Mini / ESP8266)
• Max3232 TTL to RS232 Converter with DB9 connector
• Four wires to connect the ESP with the MAX3232
• USB cord to power the ESP and if you want to use the functionality when the projector is shutdown/standby you need an additional power supply

Thats everything you need!

Wire up the ESP to the MAX3232:

ESP -> MAX
GND -> GND
3.3V -> Vin
RX -> RX
TX -> TX

You don't need any kind of crossover cables or anything else, the MAX3232 with DB9 connector is working directly at the BenQ RS232 connector

The following Lines in the code need to be prepared from yourself:

• Name of the device if you want to (Line: 3)
• ESP Board / Platform if you don't use a Wemos D1 mini (Line: 11 and 12)
• The fallback AP credentials (Line: 19 and 20)
• The OTA secret key (Line: 25)
• Home Assistant API Key (Line: 47)
• If you don't use ESPHome Builder you also have to adjust the Wifi SSID and Password the ESP should connect to (Line: 16 and 17)

You can get those informations from the ESPHome Builder Addon in Home Assistant. Just create a device, copy those information into the Yaml-file and copy/paste that Yaml into the ESPHome Builder editor.

You can download the latest Version of the Yaml-file below this post.

After the ESP is connected to Home Assistant and the BenQ projector correctly started up, the following features are possible:

Control elements:

• 3D-Mode
• Aspect Ratio
• Blue Gain
• Blue Offset
• Color Temperature
• Dynamic Iris
• Enable Error Report
• Green Gain
• Green Offset
• Lamp Mode
• Menu OFF
• Menu ON
• Mute OFF
• Mute ON
• Picture Mode
• Projector Power OFF
• Projector Power ON
• Query All Status (could also be used on first time startup to get all necessary values)
• Red Gain
• Red Offset
• Set Brightness
• Set Color Saturation
• Set Contrast
• Set Gamma
• Set HDR Brightness
• Set Sharpness
• Set Tint
• Source Selector

Sensor values:

• BenQ Error Report
• BenQ Fan 1 Speed (rpm)
• BenQ Fan 2 Speed (rpm)
• BenQ Fan 3 Speed (rpm)
• BenQ Lamp Hours
• BenQ Model Name
• BenQ Temperature 1 (Celsius)

The sensor data and actual values of the control elements are refreshing every 60 seconds. So settings you made directly on the projector are synced with the control elements after a bit of delay. If you want to, you could also adjust the polling interval to your needs (Line: 389)

Small Case:

To make everything look nice, I plan to design a small 3D-printable case in the near future. So everything could be packed into that. This is still an open task. The files for the case would be posted bellow and this post will get an update if that is done.

As always you can use <#1346797923714859018> to get in touch if you have any kind of question.