====== Cheap MP3 FM transmitter ======
start pulse:
^ signal ^ time ^ description ^
| LOW | 8.9ms | start pulse |
| HIGH | 4.4ms | start pulse |
| LOW | 619 us | bit separator |
| HIGH | 520 us | bit 0 |
| HIGH | 1600 us | bit 1 |

  * Short pulse is 0
  * Long pulse is 1
  * **LSBit is transmited first** 
  * First/left/most significant byte (MSbyte) is transmited first





Prefix **FF00** (Low byte transmitted first).

Example: **CH-** button full code would be BA45FF00, or in binary (LSBit transmitted first - right to left): 
<code>0101 1101   0010 0010   1111 1111   0000 0000</code>


^  Col 1  ^  Col 2  ^  Col 3  ^
|  **CH-** / BA45  |  **CH** / B946 |  **CH+** / B847  |
|  **<nowiki>|</nowiki><<** / BB44  |  **>><nowiki>|</nowiki>** / BF40 |  **><nowiki>||</nowiki>** / BC43  |
|  **-** / F807  |  **+** / EA15 |  **EQ** / F609  |
|  **0** / E916  |  **FOL-** / E619 |  **FOL+** / F20D  |
|  **1** / F30C  |  **2** / E718 |  **3** / A15E  |
|  **4** / F708  |  **5** / E31C |  **6** / A55A  |
|  **7** / BD42  |  **8** / AD52 |  **9** / B54A  |



===== Below information is WRONG (reversed) =====

I assumed the protocol wrongly. Below is "the wrong way" for reference of past projects.



start pulse:
^ signal ^ time ^ description ^
| LOW | 8.9ms | start pulse |
| HIGH | 4.4ms | start pulse |
| LOW | 619 us | bit separator |
| HIGH | 520 us | bit 1* |
| HIGH | 1600 us | bit 0* |
* assumed that short pulse is 1 long is 0. Not sure about that but if it's the other way - just invert all numbers below

Prefix **FF00** (High byte transmitted first)

^  Col 1  ^  Col 2  ^  Col 3 ^
|  **CH-** / 5DA2  |  **CH** / 9D62 |  **CH+** / 1DE2  |
|  **<nowiki>|</nowiki><<** / DD22  |  **>><nowiki>|</nowiki>** / FD02 |  **><nowiki>||</nowiki>** / 3DC2  |
|  **-** / 1FE0  |  **+** / 57A8 |  **EQ** / 6F90  |
|  **0** / 9768  |  **FOL-** / 6798 |  **FOL+** / 4FB0  |
|  **1** / CF30  |  **2** / E718 |  **3** / 857A  |
|  **4** / EF10  |  **5** / C738 |  **6** / A55A  |
|  **7** / BD42  |  **8** / B54A |  **9** / AD52  |