pptemp

pptemp reads temperature samples from the supported I2C temperature sensor and prints them periodically.

The current implementation is in c++/pptool.cc and uses the MCP9808 helper in c++/MCP9808.hh.

Typical usage is continuous monitoring.

Current runtime behavior

In the current pptool.cc implementation, pptemp constructs a default Args object and uses it directly. That means the active runtime behavior is currently fixed to the built-in defaults shown below.

The current helper defaults are:

I2C bus 1
sensor address 0x18
one sample per second
unlimited sample count

In the current code path, the default Args values mean the output is human-readable Celsius text rather than CSV.

Output model

For each sample the tool:

reads register 0x05 from the MCP9808 over I2C
decodes the raw value into degrees Celsius
formats the result as one output line
sleeps for the configured delay before the next sample

The underlying helper can also generate timestamped, CSV, and Fahrenheit-augmented output, but those behaviors are not currently configured by pptool.cc.

The underlying helper supports both human-readable and CSV-oriented output and can optionally include:

UTC timestamps
Fahrenheit conversion in addition to Celsius
reopen-per-sample behavior for more defensive I2C access
quiet error handling with placeholder output

This makes pptemp useful for simple interactive monitoring and plain-text logging.

Typical examples

Run continuously:

pptemp

Pipe into a log file:

pptemp >> temp.log