Something that I picked up from a comment by Hippy in the last couple of days. Powering the DS18B20 from a Picaxe output pin.
I am interested in in the concept of powering the sensor/s only at or about the time of reading, but do have a few questions.
I understand the max sink current to be 4mA and think that is during one-wire communication and the quiescent current is normally in the order of 1mA per sensor. So if running four sensors, the general saving is in the order of 4mA?
What is the required settling time between powering and reading the sensor.? I imagine that one second is more than sufficient, but am fairly curious about it. Should a pause be inserted after the READTEMP instruction and before powering down the power supply port pin, in the case of a single sensor arrangement?
In the case of multiple sensors, is there any significant advantage to be gained from powering each sensor from separate port pins, or is it just as well to power a number from the one port pin?
I'm thinking in terms of 08M2 and 18M2 chips and data logging with between four to ten (sets of) readings per hour (undecided). The short example shown uses the 08M2.
I don't think that I'm astute enough to really make a minimal power consumption device, but there is nothing like making the attempt, albeit in a piecemeal sort of fashion.
I haven't managed brevity either it seems . . .
I am interested in in the concept of powering the sensor/s only at or about the time of reading, but do have a few questions.
I understand the max sink current to be 4mA and think that is during one-wire communication and the quiescent current is normally in the order of 1mA per sensor. So if running four sensors, the general saving is in the order of 4mA?
What is the required settling time between powering and reading the sensor.? I imagine that one second is more than sufficient, but am fairly curious about it. Should a pause be inserted after the READTEMP instruction and before powering down the power supply port pin, in the case of a single sensor arrangement?
In the case of multiple sensors, is there any significant advantage to be gained from powering each sensor from separate port pins, or is it just as well to power a number from the one port pin?
I'm thinking in terms of 08M2 and 18M2 chips and data logging with between four to ten (sets of) readings per hour (undecided). The short example shown uses the 08M2.
I don't think that I'm astute enough to really make a minimal power consumption device, but there is nothing like making the attempt, albeit in a piecemeal sort of fashion.
I haven't managed brevity either it seems . . .