Is a global lambda possible?

ESPHome
1

This is a hard question to research, and even harder to title. Please bear with me as I try to explain:

One of my YAML configs uses a lot of lambdas to carry out actions for which there’s no built-in component.
That is, I need to set some C++ #define’s and instantiating a couple objects which all the other lambda’s will need to use.
For now, I’m using ‘esphome: include:’ of a classic .h file, just to get those lines at a global scope.

It’d be nice to be able put those object instantiations and #define’s in a lambda within (e.g., the ‘globals’ or perhaps the ‘esphome:’ section of) the YAML, so everything could be in one file.

Is that possible?

2

While I’m probably not able to read your “monster lambdas”, don’t be too shy to post your code. It doesn’t hurt anybody…

3

The lambda code isn’t large at all, but might not make much sense since it is to operate a stepper motor in a special clock.
Here are the lines in the .h file I can’t migrate to the YAML.

Adafruit_MotorShield AFMS = Adafruit_MotorShield();
Adafruit_StepperMotor *myMotor = AFMS.getStepper(96, 2); // 96 steps per rev, board channel 2

To operate it requires that I instantiate the Adafruit Motor Shield library. Which I can only do in a C++ file (the aforementioned .h file).
Formerly, I had followed the pattern for a ‘Custom Component’ but as I found that I could factor out portions of the code into lambdas which could fit into automation elements like ‘on_time…’, I got it to the point where the only things left in the Custom Component were the few lines in .h that were C++ #define’s and a couple instantiations.
The #define’s can simply be YAML ‘globals’ that I treat as constants.
But the object creation isn’t one I can port to YAML.
Even the library inclusion was handled by the YAML ‘libraries’ section.
I went as far as trying an item under ‘globals:’ with type ‘Adafruit_MotorShield’ but ESPHome’s precompiler rejected it as undefined.

4

The YAML code. In the comments is the content of the .h file it references.

# Chrono -
  # Linear Clock - GLD - Summer 2018
  # Stepper motor control, NTP time sync, limit switch sensing

  # Pointer tracking, in motor 'steps':
  # zero is 'bottom.' Midnight is 2" up from there, at MIDNIGHT_POSITION
  # Noon is 12 * STEPS_PER_HOUR further up, at NOON_POSITION
  # the limit switch triggers about 1.5" above that (somewhere around 77277 steps)
  # so at startup, we have to presume the pointer is out of bounds and needs to reach the limit switch
  # but rather than have it do all that seeking when power bounces, we're going to presume it is already close to
  # where it should be, and just recalibrate every noon, when the distance to the limit switch is smallest.

  # 30" travel per 12 hours
  # = 2.5" per hour
  # Current threaded rod pitch: 24/inch
  # Current servo-steps: 96/revolution
  # Results in:
  # 96 steps/minute
  # = 5760 steps/hour
  # = 1.6 steps/second
  # = 8 steps / 5 seconds

  # Motor is driven by an Adafruit "DC Motor + Stepper FeatherWing Add-on For All Feather Boards"
  # Adafruit product # 2927
  # https://learn.adafruit.com/adafruit-stepper-dc-motor-featherwing

# TODO:
# make it respond immediately to the limit switch (which it can't do if stepping more than 1 at a time)
# find a quiet stepping mode that's also non-blocking
# figure out how to put this into 'globals:'
    # #define ABOVE_LIMIT_SWITCH 78336
    # #define LIMIT_SWITCH_LOCATION 72777
    # #define NOON_POSITION 69120
    # #define MIDNIGHT_POSITION 0
    # // 12 hours * 60 minutes * 96 steps/minute = 69120
    # #define STEPS_PER_HOUR 5760
    # #define STEPS_PER_MINUTE 96
    # #define STEPS_PER_SECOND 1.6
    # Adafruit_MotorShield AFMS = Adafruit_MotorShield();
    # Adafruit_StepperMotor *myMotor = AFMS.getStepper(96, 2); // 96 steps per rev, board channel 2


esphome:
  name: ${node_name}
  includes:
    - common/chrono.h
    - <Adafruit_MotorShield.h>
  libraries:
    - "Wire"
    - "SPI"
    - "Adafruit BusIO"
    - "Adafruit Motor Shield V2 Library"
      # Motor Library reference: https://learn.adafruit.com/adafruit-stepper-dc-motor-featherwing/library-reference

  on_boot:
    priority: -100
    then:
      - lambda: |-
          AFMS.begin(); // initialize, using the default PWM frequency 1.6KHz
          myMotor->setSpeed( 60 ); // a modest speed seems mostly important to accurate SINGLE stepping mode, not MICROSTEP
          myMotor->release();
          id(afms_setup_complete) = true;

  on_loop:
    then:
      # stepping has to be done one at a time, so it can properly handle changes to pointer position (e.g. limit switch)
      - lambda: |-
          // don't run this if AFMS isn't setup yet, it will crash
          if( ! id(sntp_time).now().is_valid() || ! id(afms_setup_complete) ) { return; }

          id(stepsNeeded) = (id(desired_pointer_position) - id(presumed_pointer_position));
          if( id(stepsNeeded) != 0 ) {
            myMotor->step( 1
              , id(stepsNeeded) > 0 ? FORWARD : BACKWARD
              , abs(id(stepsNeeded)) > STEPS_PER_MINUTE ? SINGLE : MICROSTEP
              );
            if( id(stepsNeeded) > 0 ) id(presumed_pointer_position)++; else id(presumed_pointer_position)--;
            myMotor->release();
          }

time:
  - platform: sntp
    servers: '10.1.1.1'
    id: sntp_time
    timezone: 'America/Indiana/Indianapolis'
    on_time_sync:
        then:
          - script.execute: do_time_calc
          - text_sensor.template.publish:
              id: text_timesync
              state: !lambda |-
                return( id(sntp_time).now().strftime( "%c" ) );
    on_time:
      # every minute on the mark, choose the new pointer position
      - seconds: 0
        then:
          - script.execute: do_time_calc

      # every second, update the webpage time so it looks like something's happening
      - seconds: '*'
        then:
          - text_sensor.template.publish:
              id: text_time
              state: !lambda |-
                return( id(sntp_time).now().strftime( "%c" ) );

      # at noon, if it's 1st of month or calibration needed after startup, do so
      - seconds: 0
        minutes: 0
        hours: 12
        then:
          - if:
              condition:
                lambda: |-
                  return( id(sntp_time).now().is_valid() &&
                    ( id(sntp_time).now().day_of_month == 1 || id(calibration_needed) ) );
              then:
                - script.execute: recalibrate_now

script:
  - id: do_time_calc
    then:
      - lambda: |-
          if( id(stepsNeeded)==0 && id(sntp_time).now().is_valid() ) {
            unsigned long thisSecond = id(sntp_time).now().second;
            if (id(sntp_time).now().hour < 12) {
              // id(desired_pointer_position) = MIDNIGHT_POSITION + (id(sntp_time).now().hour * STEPS_PER_HOUR) + (id(sntp_time).now().minute * STEPS_PER_MINUTE) + (thisSecond * STEPS_PER_SECOND);
              id(desired_pointer_position) = MIDNIGHT_POSITION + (id(sntp_time).now().hour * STEPS_PER_HOUR) + (id(sntp_time).now().minute * STEPS_PER_MINUTE);
            } else {
              // id(desired_pointer_position) = NOON_POSITION - ((id(sntp_time).now().hour - 12) * STEPS_PER_HOUR) - (id(sntp_time).now().minute * STEPS_PER_MINUTE) - (thisSecond * STEPS_PER_SECOND);
              id(desired_pointer_position) = NOON_POSITION - ((id(sntp_time).now().hour - 12) * STEPS_PER_HOUR) - (id(sntp_time).now().minute * STEPS_PER_MINUTE);
            }
            if( id(time_first_pass) ) { // presume the pointer is already close to where it needs to be
              id(presumed_pointer_position) = id(desired_pointer_position);
              id(time_first_pass) = false;
            }
          }
  - id: recalibrate_now
    then:
      - lambda: |-
          id(presumed_pointer_position) = 0;
          id(desired_pointer_position) = ABOVE_LIMIT_SWITCH;

binary_sensor:
  platform: gpio
  id: limit_switch
  name: "${node_name} Limit Switch"
  internal: true
  pin:
    number: 14
    mode:
      input: true
      pullup: true
  filters:
    # - invert: # needed for normally-open switch
    - delayed_on_off: 100ms
  on_press:
    then:
      # note that the pointer is now pressing the limit switch
      - lambda: |-
          id(stepsNeeded) = 0; // stop any motion immediately (redundant with math done in loop)
          id(calibration_needed) = false;
          id(presumed_pointer_position) = LIMIT_SWITCH_LOCATION;
          id(desired_pointer_position) = NOON_POSITION;

button:
  - platform: template
    name: "Recalibrate now"
    on_press:
      - logger.log: Recalibrate Button Pressed
      - script.execute: recalibrate_now

globals:
  - id: time_first_pass
    type: boolean
    initial_value: 'true'
  - id: calibration_needed
    type: boolean
    initial_value: 'true'
  - id: afms_setup_complete
    type: boolean
    initial_value: 'false'
  - id: presumed_pointer_position
    type: int
    initial_value: '0'
  - id: desired_pointer_position
    type: int
    initial_value: '0'
  - id: stepsNeeded
    type: int
    initial_value: '0'

# =================================
# UI stuff is below here

text_sensor:
  - platform: template
    name: "${node_name} Time, SNTP"
    id: text_time
    internal: true
    icon: mdi:clock-start
  - platform: template
    name: "${node_name} Time, last NTP sync"
    id: text_timesync
    internal: true
    icon: mdi:clock-start

# number:
  - platform: template
    name: "${node_name} Pointer, Presumed Position"
    internal: true
    update_interval: 1s
    lambda: |-
      char buffer[32];
      sprintf( buffer, "%u", id(presumed_pointer_position));
      return {buffer};
    # set_action:
    #   - lambda: |-
    #       id(presumed_pointer_position) = x;
    # update_interval: 1s
    # id: presumed_pointer_position_number
    # mode: box
    # entity_category: 'config'
    # max_value: 80000
    # min_value: 0
    # step: 1

  - platform: template
    name: "${node_name} Pointer, Desired Position"
    internal: true
    update_interval: 1s
    lambda: |-
      char buffer[32];
      sprintf( buffer, "%u", id(desired_pointer_position));
      return {buffer};
    # set_action:
    #   - lambda: |-
    #       id(desired_pointer_position) = x;
    # update_interval: 1s
    # id: desired_pointer_position_number
    # mode: box
    # entity_category: 'config'
    # max_value: 80000
    # min_value: 0
    # step: 1

# =================================

output:
  - platform: esp8266_pwm
    id: output_blue_led
    pin: GPIO2
    inverted: True
  - platform: esp8266_pwm
    id: output_red_led
    pin: GPIO0
    inverted: True

i2c:

api:
  reboot_timeout: 0s  # ignore absence of HomeAssistant

esp8266:
  board: huzzah
  # framework:
  #   version: latest

#========================================
substitutions:
    node_name: chrono

packages:
  # diag_info: !include common/diag_info.yaml
  ## device_base seems to need to be last one in this block
  device_base: !include common/device_base.yaml

logger:
  # baud_rate: 0
  level: DEBUG
  # level: VERY_VERBOSE
  logs:
    number: INFO
    text_sensor: INFO
    sensor: INFO
    component: ERROR # avoid seeing hundreds of complaints about servo steps being slow

ota:
  - platform: esphome
    on_begin:
      then:
        - lambda: |-
            id(stepsNeeded) = 0;
            myMotor->release();