You can operate up to four Dreamboxes in the same room with IR signals by configuring each box and its remote to use one of four available IR addresses. By default, a Dreambox reacts to all four addresses.
To build an IR code, you need to learn a little bit about its structure. Each NEC IR code is a 32-bit number consisting of four 8-bit numbers:
1. Address
2. Inverse Address
3. Data
4. Inverse Data
Valid values for Address and corresponding Inverse Address
Valid values for data if address is either 32h or 33h
Valid values for data if address is either 34h or 35h
*) Used by remotes with address 35h
**) Used by remotes with address 34h
Example code calculation
Suppose you want to send a MUTE key code for address 32h. First look up or calculate the inverse address for 32h: CDh. Then look up the value of MUTE in the first data table: 1Ah. Calculate its inverse value: 1Ah XOR FFh = E5h. The resulting IR code is the concatenation of all four hexadecimal values: 32h CDh 1Ah E5h -> 32CD1AE5h, or 0x32CD1AE5 in another notation.
How to use it?
If you don't own a universal remote already that let's you enter raw NEC codes, there are many cheap ESP8266-based devices available on the market, which are supported by the open source software Tasmota. There's a Tasmota-IR firmware variant, which supports additional IR protocols.
Tasmota allows sending IR commands via MQTT or from the console. To send the code calculated above, the console command looks like this:
IRSend {"Protocol":"NEC","Bits":32,"DataLSB":"0x32CD1AE5"}Some related articles:
- https://tasmota.github.io/docs/devices/YTF-IR-Bridge/