Groups and values

By default:
- there are 8 groups maximum and they are numbered from 0 to 7.
- there may be maximum 16 buttons per group.
- each button can have a value (identifier) freely chosen between 0 and 15.

We can change these default values if:
- we want more than 8 groups
or
- we want more than 16 switches in one of the groups.

In the library file MTobjects.h, the first lines indicate:

#define RADIO_NB_BITS_GROUPE 3 // Number of bits for the definition of the radio group 0..6
                               // 0: 1 group of 128 buttons maximum
                               // 1: 2 groups maximum of 64 buttons max each
                               // 2: 4 groups maximum of 32 buttons max each
                               // 3: 8 groups maximum of 16 buttons max each
                               // 4: 16 groups maximum of8 buttons max each
                               // 5: 32 groups maximum of 4 buttons max each
                               // 6: 64 pairs of buttons maximum

We can change the number 3 in red above to change the default values. Be careful this only indicates the maximums. If we only need 2 buttons in all (so in the same group) we can replace number 3 in red with any number between 0 and 6. In this case, we do not touch anything. Note that as much as possible you can have 128 buttons, but that you can only have 70 pins with a MEGA. Nevertheless if a button was to belong to several groups, it would be necessary to define it several times with the same pin number, but with different group numbers.

For the first 4 groups, instead of using a number, we can use:

RADIO_GROUP_0
RADIO_GROUP_1
RADIO_GROUP_2
RADIO_GROUP_3

And for the first 10 buttons, we can use:

RADIO_BUTTON_0
RADIO_BUTTON_1
RADIO_BUTTON_2
RADIO_BUTTON_3
RADIO_BUTTON_4
RADIO_BUTTON_5
RADIO_BUTTON_6
RADIO_BUTTON_7
RADIO_BUTTON_8
RADIO_BUTTON_9

It is equivalent but it automatically comments on the number. Instead of writing:

MTradioButton button(0, one, two, 0, 1, 2);

It is better to write:

MTradioButton Button(pinOn, lightOn, lightOff, LOW if_not_pressed, RADIO_BUTTON_1, RADIO_GROUP_2);

By default when you omit to specify the group, it is group 0 which is implemented. In the case we have only one group, we may not specify the group number.

Include to add

#include <MTobjects.h> // See http://arduino.dansetrad.fr/en/MTobjects

I strongly advise to leave the comment, if another person wanted to try the program, they would have a download link directly. This is valid for all the libraries you use.

Useful comment

if_not_pressed

This comment is a word that can be added anywhere and which is ignored by the compiler.

Constructor

MTradioButton(pin,
              onSelectFunction = NO_ACTION,
              onUnselectFunction = NO_ACTION,
              rest = HIGH, 
              valeur = 0,
              groupe = 0);

• pin (uint8_t): pin to which the button is connected
• onSelectFunction: what happens when you activate the button
  • NO_ACTION -> nothing happens
  • myFunction → call a function "void myFunction(void) {...}"
• onUnselectFunction: what happens when the button is desactived
  • NO_ACTION -> nothing happens
  • myFunction → call a function "void myFunction(void) {...}"
• rest (boolean): pin state if the button is release
  • HIGH -> if it is wired between GND and pin (recommended). The pullup resistor is automatically added
  • LOW -> if it is wired between VCC and pin, with a pulldown resistance between pin and GND
• valeur (byte): arbitrary number associated with the button. This allows you to differentiate it in a group; 0 to 15
• groupe (byte): group number 0..7

Useful functions

void select(void);
void unselect(void);
boolean getSelect(void);
virtual void onSelect(void);
virtual void onUnselect(void);

select: select the button
unselect: unselect the button
getSelect: return true if the button is selected
onSelect: overload function called when pressing the button
onUnselect: overload function called when the button is unselected

Useful global functions
(not belonging to the object)

void unselectMTradioButton(char groupe = 0);
void unselectMTradioButton();
byte getMTradioButtonValeur(char groupe = 0);
byte getMTradioButtonValeur();

unselectMTradioButton: deselects all the radios buttons of a group
getMTradioButtonValue: Returns the value of active control of the group

Bonus functions

byte getValeur();
byte getGroupe();
void setOnSelectFunction(onSelectFunction);
void setOnSelectFunction();
void setOnUnselectFunction(onUnselectFunction);
void setOnUnselectFunction();

getValeur: return the value of the button
getGroupe: return the button group number
setOnSelectFunction: changes the function called when pressing the button
setOnSelectFunction: without parameters removes the function called when pressing the button
setOnUnselectFunction: changes the function called when the button is unselected
setOnUnselectFunction: without parameters removes the function called when the button is unselected

Examples

• LW-MW-FM
• LW-MW-FM derivative class