pw_arduino_build#
The pw_arduino_build module contains both the arduino_builder command
line utility and an Arduino Main Wrapper.
See also
See the Arduino target documentation for a list of supported hardware.
Arduino Main Wrapper#
arduino_main_wrapper.cc implements the standard setup() and loop()
functions [1] that are expected in Arduino sketches.
Pigweed executables rely on being able to define the main() function. This
is a problem for Arduino code as each core defines it’s own main(). To get
around this the Pigweed Arduino target renames main() to ArduinoMain()
using a preprocessor macro: -Dmain(...)=ArduinoMain(). This macro only
applies when compiling Arduino core source files. That frees up main() to be
used elsewhere.
Most Arduino cores will do some internal initialization before calling
setup() followed by loop(). To make sure Pigweed main() is started
after that early init we run it within setup():
void setup() {
pw_arduino_Init();
// Start Pigweed main()
main();
}
void loop() {}
Note
pw_arduino_Init() initializes the pw_sys_io_arduino
module.
Warning
You may notice loop() is empty in arduino_main_wrapper.cc and never
called. This will cause any code appearing after loop() in an Arduino
core to never be executed. For most cores this should be ok but may cause
issues in some scenarios.
arduino_builder#
arduino_builder is utility that can extract compile and tooling information
from an Arduino core. It’s used within Pigweed to shovel compiler flags into
the GN build system. It will also work
without Pigweed and can be used with other build systems.
Full documentation is pending. For now run arduino_builder --help for
details.
Footnotes