Global Variables¶
In some cases you might need to share a global variable across multiple lambdas. For example, global variables can be used to store the state of a garage door.
# Example configuration entry
globals:
- id: my_global_int
type: int
restore_value: no
initial_value: '0'
# Example for global string variable
- id: my_global_string
type: std::string
restore_value: yes
max_restore_data_length: 24
initial_value: '"Global value is"'
# In an automation
on_...:
then:
- lambda: |-
if (id(my_global_int) > 5) {
// global value is greater than 5
id(my_global_int) += 1;
} else {
id(my_global_int) += 10;
}
ESP_LOGD(TAG, "%s: %d", id(my_global_string).c_str(), id(my_global_int));
Configuration variables:
id (Required, ID): Give the global variable an ID so that you can refer to it later in lambdas.
type (Required, string): The C++ type of the global variable, for example
bool
(fortrue
/false
),int
(for integers),float
(for decimal numbers),int[50]
for an array of 50 integers, etc.restore_value (Optional, boolean): Whether to try to restore the state on boot up. Be careful: on the ESP8266, you only have a total of 96 bytes available for this! Defaults to
no
.max_restore_data_length (Optional, integer): Only applies to variables of type
std::string
. ESPHome will allocate enough space for this many characters, plus single character of overhead. Strings longer than this will not be saved. The max value of this variable is 254 characters, and the default is 63 characters.initial_value (Optional, string): The value with which to initialize this variable if the state can not be restored or if state restoration is not enabled. This needs to be wrapped in quotes! Defaults to the C++ default value for this type (for example
0
for integers).
globals.set
Action¶
This Action allows you to change the value of a global
variable without having to use the lambda syntax.
on_...:
- globals.set:
id: my_global_var
value: '10'
Configuration variables:
value (Required, templatable): The value to set the global variable to.
Note
This action can also be written in lambdas:
id(my_global_var) = 10;