Hi all, Hoping for some advanced but perhaps obvious answers here.
The background, I have a solar controller ( solarfocus Mk-2 ) which uses three DS18x20 sensor's wired directly to it's board to monitor specific temps, in the tubes, and the top and bottom of a tank of water.
Everything works great, however, it's all located in my garage, and the tank of water, is in the house, What i was hoping to do was monitor via a sonoff th16 each sensor and in turn report on the temp ( simples )
The sensor's are two wire devices, so parasite power, where the controller appears to be pulling up the 3.3/5 v's on to the Data line.. Again all is good here.
On my sonoff's I can wire up a 2.5 mm jack, and attach to the senor's mid wire, to say GPIO14, and GND, however in doing so, the Sonoff will also pull up the VDD to 3.3 /5v
I'm concerned that in doing so, i'll be sending power twice, and possibly fry something in the process.
My resolution if the above is going to be an issue, Use GPIO4 bridge with a 0K resister but dont connect the 3.3v with a 10K resister. this would hopefully allow the sonoff to read the data from the sensor, and allow only the MK-2 provide the pull up..
Original thread altho slightly in reverse is here
The background, I have a solar controller ( solarfocus Mk-2 ) which uses three DS18x20 sensor's wired directly to it's board to monitor specific temps, in the tubes, and the top and bottom of a tank of water.
Everything works great, however, it's all located in my garage, and the tank of water, is in the house, What i was hoping to do was monitor via a sonoff th16 each sensor and in turn report on the temp ( simples )
The sensor's are two wire devices, so parasite power, where the controller appears to be pulling up the 3.3/5 v's on to the Data line.. Again all is good here.
On my sonoff's I can wire up a 2.5 mm jack, and attach to the senor's mid wire, to say GPIO14, and GND, however in doing so, the Sonoff will also pull up the VDD to 3.3 /5v
I'm concerned that in doing so, i'll be sending power twice, and possibly fry something in the process.
My resolution if the above is going to be an issue, Use GPIO4 bridge with a 0K resister but dont connect the 3.3v with a 10K resister. this would hopefully allow the sonoff to read the data from the sensor, and allow only the MK-2 provide the pull up..
Original thread altho slightly in reverse is here