Resistor Selection #262
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The documentation suggests using a 33k resistor for the clock and read pins for esp8266/esp32 and a 15k resistor for arduino boards. The PCB schematic lists 15k resistor for the NodeMCU board. Is this resistor value critical? Im building a board with an esp32 NodeMCU and I was going to use a 33k resistor here but I just wanted to double check.
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Replies: 3 comments
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DSC operates at 12.6V, Arduino at 5V, and ESP at 3.3V. |
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Thanks that answers my question. |
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Or rather build an isolated ground version It is easy to do even on a prototype board with all straight wires This is safer and won't does not put load on the DSC Aux line. |
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DSC operates at 12.6V, Arduino at 5V, and ESP at 3.3V.
The resistors act as a voltage divider.
Vout = Vin R2 / (R1+R2).
So with 10k and 15k we get:
Vout = 12.6 * 10 / 25 = 5.06 good for Arduino
And with 10k and 33k:
Vout = 12.6 * 10 / 43 = 2.93 good for ESP