pico-examples
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raspberrypi
Blink gpio10
Propose an additional blink example that
- Uses an external led to work with both the pico and pico w
- Provides a serial out message
- Shows how to declare a variable used for debugging with "volatile" to avoid the inspected value showing as "optimized out"
As far as I know the existing blink.c using the on-board LED works on both Pico and Pico W? https://github.com/raspberrypi/pico-examples/blob/master/blink/blink.c
However, if we were going to include something like this — an additional blink example using an external LED — just like the two "hello world" examples (hello_usb and hello_serial) it should live in a sub-directory of the existing blink example, which should then be renamed and moved to its own subdirectory inside the existing blink/ directory.
In addition, since it's a getting started example, I think it should have a wiring diagram as it requires external wiring, e.g. see https://github.com/raspberrypi/pico-examples/tree/master/i2c/bmp280_i2c where there is a README.md file with an included wiring example.
That said, a blink example needs to be the simplest thing possible, parsable by folks that don't even know C, and are just familiar with other languages, and this is far longer and much more complex than the existing blink example. I don't believe this is suitable for folks that'll be looking to a blink example as their very first experience of the SDK.
That blink example doesn't work on Pico W. There's a separate one for Pico W https://github.com/raspberrypi/pico-examples/blob/master/pico_w/wifi/blink/picow_blink.c
In the spirit of keeping it simple, someone just starting may purchase the pico w as their first board (I did because I want to do an IOT project).
- It is not immediately obvious that the current blink example does not work on the pico w.
- The pico w blink example is pretty well buried in the examples directory tree.
- picow_blink it is a slightly more complex program because the onboard led is tied to the wifi module rather than being a standard gpio => not a good teaching example.
For those reasons, the current blink example should be updated to be pico w friendly.
No problem leaving out the serial coms and the "volatile" declaration for simplicity.
For the record I fell into this trap getting started, flashing the pico examples on a pico w, scratching my head and flailing about until I realized my mistake. A few more breadcrumbs and safety nets wouldn't hurt the experience.
Is it going to be any more obvious when you need a led and a resistor to make it work?