Available functions to use from a library

Projects Programming
1

This is my first post. Please be kind.

This is the short version of the question:

How do I obtain a list of functions available to use in a library?

This is the long version if you care to read:

I have built a DS18B20 temp logger using 8 probes on the one bus.
A readily available sketch that employs the OneWire.h and DallasTemperature.h libraries uses the void functions sensors.requestTemperatures() and to print to serial printTemperature(Probe01) or up to Probe08 in my case.

My project includes writing a timestamp then each ID of the probe (Probe1 or its Hex address) with its temp in Celsius to a datalog.csv on an SD card. I can create the file and print the temps to serial. The problem is not being able to assign it to a string in order to print that to the log file. If I attempt to do sensordatastring = String(printTemperature(Probe01) it errors because printTemperature() is a void function and not a value returning function.

Is there are way to return a value using these libraries or do I need to read each bit from the scratchpad and assign it to an integer?
Kevin Darrah had a great sketch that does all of this but I don't know how to edit it to get the addresses and temps to save to an SD card log file instead of just printing to the serial monitor.

2

Why on earth do you need to assign it to a String? Can't you write it directly to the file?

3

How do I obtain a list of functions available to use in a library?

A well documented library would provide a list of functions and give examples.

You can look at the .h and .cpp files of the library to see the available functions, their inputs and return values. You could also add functions to the library.

4

The problem is not being able to assign it to a string in order to print that to the log file. If I attempt to do sensordatastring = String(printTemperature(Probe01) it errors because printTemperature() is a void function and not a value returning function.

You do not need to be storing the data in a String. Why would you assume that a function named printTemperature() would do anything BUT print the temperature?