Attributes

Attributes are input parameters that the user can set in diagram.json. You can also define a controls section in the .chip.json file to let the user edit these parameters interactively during the simulation. This is particularly useful for sensor inputs (e.g. temperature, humidity, etc.).

Naming

When naming your attributes, please follow the following conventions:

• Use camelCase for attribute names
• Use American English spelling (e.g. color and not colour)

uint32_t attr_init(const char *name, uint32_t default_value)

Defines a new integer attribute with the given name. The default_value will be used when the user does not define a value for the attribute in diagram.json (under the attrs section of the custom chip part).

The function returns a handle to the attribute, which can be accessed using attr_read().

caution

Note: attr_init can only be called from chip_init(). Do not call it at a later time.

uint32_t attr_init_float(const char *name, float default_value)

Defines a new floating point attribute with the given name. See attr_init() for more info.

caution

Note: attr_init_float can only be called from chip_init(). Do not call it at a later time.

uint32_t attr_read(uint32_t attr)

Returns the current value of the attribute. attr should be a valid attribute handle, previously returned by attr_init().

float attr_read_float(uint32_t attr)

Returns the current value of the attribute. attr should be a valid attribute handle, previously returned by attr_init_float().