Only UP/DOWN/ENTER button, how to edit values?

[SanderM2]

I'm trying to use GEM on an Industruino (https://industruino.com) device that only has an UP, DOWN and ENTER button.
I'm succesfully running the Example-02_Blink.ino example on it right now but if I want to change the Interval, a variable. I can only change the first number of the value. So for example, change 500 to 400 or 300 etc...
But I cannot set it to 350 because I don't have a left or right button.

Is there a way make GEM cycle through the digits using only the UP/DOWN/ENTER buttons?
Like, when I press enter, it should cycle to the next digit, let me change it and continue until all 3 digits are changed?

Thanks

[Spirik]

Hello!

At the moment it may require some source code modification, I am afraid. For example, you can make GEM._editValueMode property public, and by checking it in your loop decide what to do when pressing Enter button: if _editValueMode is true then you are in edit mode and subsequent presses of Enter button (aka GEM_KEY_ENTER) should be interpreted as Right key (aka GEM_KEY_RIGHT), unless the end of a variable string is reached (and it may be tricky to track that part).

Alternatively, you may want to consider avoiding editable variables altogether in favor of making use of Selects, Checkboxes and Buttons (if it is acceptable in your specific case, of course).

However I still plan on adding special means of tracking current state of GEM object (accessing currently selected Menu item object, its value, menu states, etc.) to make it a little bit easier to customize behavior of input methods. That will be added in some future versions of library, but no estimates as of now. You may see the discussion here for some additional context.

[Spirik]

Additional thing you can try to do (without the need to modify GEM source code) is to detect quick-time events (QTE) with what buttons you have available: e.g. quick double click of Enter/GEM_KEY_ENTER (or Up/GEM_KEY_UP, or Down/GEM_KEY_DOWN) button may be interpreted as GEM_KEY_RIGHT action.

For that you would have to write your own key detection method and call menu.registerKeyPress with action you would like to perform.

Please, refer to Control menu from your sketch section of wiki for details.

[zandernc]

Hi - I'm rather new to all this so apologies in advance if any of this is clueless... but I'd like to add my voice in support of GEM working with just a rotary encoder and a single button - it's such an efficient UI input when you are trying to make a simple menu-based project. Maybe it's worth implementing? In my experience the difference between the "ok" button and the "right" button are pretty similar, and... I'm not sure you lose much functionality if you make them equivalent. Changing your source code is far beyond my skills... Thank you!

[Spirik]

Hi, zandernc!

It should be possible to use rotary encoder (or any other input device) with GEM without the need to modify source code (although edition of variables in this mode will require some creative solutions)!

There is no example for rotary encoders specifically, but theoretically as soon as input device (or rather your sketch) can produce 6 basic operations that menu understands (up, right, down, left, ok, cancel) it should be completely possible. But it is up to you to figure out how to extract those readings from encoder (or any other input device for that matter). Presumably with the use of some 3rd party library, such as Encoder.

See Control menu from your sketch section of wiki for a little more details. You may want to look into how KeyDetector or U8g2 key detection organized in supplied examples (in their loop()) as a starting point.

You also may be interested in the following discussions:

• Use with Rotary Encoder? #36
• Encoder or/and 4x4_over_i2c_multiplexer #61
• Menu controlling via serial port #57 (shows possible way to control GEM from custom device, in this case - Serial port)
• Context Loop only triggers on input #71 (issue itself not related to the topic, but author provides listing of the code in which GEM is operated using rotary encoder)

Hope navigating through those resources helps!

[zandernc]

Just to follow up - I was able to implement a very functional version of the menu using an encoder with a button - turning the encoder for up and down keypresses, and a short press of the encoder for right keypress and a long press of the encoder for "ok." Works great! Thank you Spirik!

[Spirik]

One other possible solution, as I mention in #36, is to detect turning the encoder while pressed (may not be compatible with all of the encoders though). If it is supported by encoder, then I would suggest to consider the following scheme:

• Rotation - Up, Down;
• Rotation while pressed - Left, Right;
• Short press - Ok;
• Long press - Cancel.

That way we will cover all 6 interactions GEM is able to respond to.

[Spirik]

👋 FYI: just updated GEM with examples on how to control menu with rotary encoder using latest version of KeyDetector (implementing control scheme described above).