Peter M. Groen / DALI-Lighting-Interface

Commit fafabc60b9edc40b6cbe0c38c3306984db0c3ce5

Authored by qqqlab
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README.md
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... ... @@ -12,8 +12,8 @@ Needs a DALI hardware interface such as Mikroe DALI click. Or use this very basi
12 12  
13 13 ```
14 14 Micro- 5.6V ___ DALI BUS
15   -controller Zener +----|___|---- 16-22V
16   - ___ Diode | 100
  15 +controller Zener +----|___|---- 10-22V
  16 + ___ Diode | 100
17 17 RX ---|___|---|>|---+------------- DALI+
18 18 10K |
19 19 ___ |/
... ... @@ -22,8 +22,9 @@ controller Zener +----|___|---- 16-22V
22 22 V
23 23 GND -----------------+------------- DALI-
24 24 ```
25   - NOTES:
26   - - For this interface, reverse the polarity of TX in the code.
27   - - Might not work with all DALI components because of unmatched voltage levels.
28   -
  25 +NOTE: For this interface, reverse the polarity of TX in the code.
  26 +
  27 +### Explanation of the circuit
  28 +
  29 +The DALI bus needs to be powered with a 16V (9.5V to 22.5V) power supply, current limited to 250mA. In the circuit the 100 ohm resister acts as the current limiter. A logic low is -6.5V to 6.5V, a logic high is 9.5V to 22.5V. The zener diode takes removes the 6.5V offset, and the 10K resistor together with the shunt diodes in the GPIO port protect the microcontroller from overcurrent & overvoltage.
29 30  
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