A card that tells me when I should start various appliances, but only when there actually is some data.

[AkshayRao27]

Credit & Disclaimer

I generated most of this code using ChatGPT 4, as well as with the Home Assistant Assistant GPT. I'm not a programmer by any stretch of the imagination, and this post is a mix of documentation & instruction, so that when I inevitablity forget how any of this works about 2½ weeks from now, future me has something to fall back on. If you need any kind of technical help with any of the stuff below, I don't know how much I will be able to contribute ¯\_(ツ)_/¯

What this card does

• It displays when I should start my dishwasher, both in terms of time as well as in terms of the hours & minutes from now (my dishwasher only lets me set a "Start in x hours" timer).
• It displays when the 30° / 60° washing machine batches should end, both in terms of time as well as in terms of the hours & minutes from now (my washing machine only lets me set an "End in x hours" timer).
• If the time window for any of these entries have already passed, it hides that entry.
• If the time window for all of these entires has already passed, it hides the whole card.

The Card

All Schedules:

Only some schedules:

Prerequisites

1. Install the necessary integrations

This card requires the EPEX Spot Sensor integration to create the entities that will feed it data, as well as Card Tools & Secondary Info entity Row for actually creating the card. All of these can be installed via HACS.

2. Create EPEX Spot Sensors

You need one EPEX Spot Sensor that determines the cheapest time-window for each cycle of each appliance. In my case, that meant three sensors.

After installing the integration, create a "helper" by going to Settings → Devices & Services → Helpers → Create Helper → EPEX Spot Sensor.

My dishwasher cycle takes 3 hours & 15 minutes to run, and I don't care when the dishwasher comes on, so this is how I configured that sensor:

For the washing machine however, I don't want to have a batch end after 11 pm or before 5:30 am. That way I can take care of putting the laundry on the drying rack before going to bed / heading to work instead of leaving it in the washing machine to ferment like a nice Sourdough loaf. So this is how I configured the 30° / 60° Batch Sensors (with slightly different values of course):

These are the three sensors that we will be extracting data from

Appliance	Sensor (Friendly Name)	Sensor (Entity Name)
Dishwasher	Dishwasher: Cheapest Window	binary_sensor.dishwasher_cheapest_window
Washing Machine	30° Batch: Cheapest Window	binary_sensor.30deg_batch_cheapest_window
Washing Machine	60° Batch: Cheapest Window	binary_sensor.60deg_batch_cheapest_window

3. Create Template Sensors for extracting the correct time

Once all of the EPEX Spot Sensors are set up, we need to extract either the start or the end time depending on the appliance.

Since I can only tell my dishwasher when to start, I need to know what time I should start it at.

Create a Template Sensor by going to Settings → Devices & Services → Helpers → Create Helper → Template → Template a sensor. Under "State Template", enter

{% set future_windows = state_attr('binary_sensor.dishwasher_cheapest_window', 'data') | selectattr('start_time', 'gt', now().timestamp() | timestamp_local) | list %}
{% if future_windows %}
  {{ (strptime(future_windows[0]['start_time'], '%Y-%m-%dT%H:%M:%S%z')).strftime('%H:%M on %d/%m/%y') }}
{% else %}
  Waiting for new data
{% endif %}

WAT

Here's what's happening:

• We start by setting a variable called future_windows where
  • state_attr('binary_sensor.dishwasher_cheapest_window', 'data') retrieves the data attribute from binary_sensor.dishwasher_cheapest_window.
    This data is a list of up to two entries for start_time
    (I am using smartENERGY.at which gives me data for the present day and the next day).
  • selectattr('start_time', 'gt', now().timestamp() | timestamp_local | list %) filters the start_time list and selects entries where start_time is greater than (gt) the current timestamp (now().timestamp()), converted to the local timezone (| timestamp_local). This ensures only future windows are considered. Then, | list % converts the filtered result back into a list (since the filtering process apparently does not return a list).
• if future_windows is NOT empty (%), then
  • strptime(future_windows[0]['start_time'], '%Y-%m-%dT%H:%M:%S%z') parses the start_time of the first ([0]) future window from a string, into a datetime object (%Y-%m-%dT%H:%M:%S%z), allowing us to then use
  • strftime('%H:%M on %d/%m/%y')** to format the datetime object as we want.
• else: Waiting for new data: In case future_windows is indeed empty, that means that all of the possible start_times are in the past, and we need to wait for new data from the provider.

Now for the two washing machine sensors. Here, we need theend_time and not the start_time. The rest of the code is essentially the same. Here's the 30° Batch Sensor:

{% set future_windows = state_attr('binary_sensor.30deg_batch_cheapest_window', 'data') | selectattr('end_time', 'gt', now().timestamp() | timestamp_local) | list %}
{% if future_windows %}
  {{ (strptime(future_windows[0]['end_time'], '%Y-%m-%dT%H:%M:%S%z')).strftime('%H:%M on %d/%m/%y') }}
{% else %}
  Waiting for new data
{% endif %}

For the 60° Batch Sensor, simply replace binary_sensor.30deg_batch_cheapest_window with binary_sensor.60deg_batch_cheapest_window

4. Create Template Sensors for calculating the duration

Knowing what time to start the dishwasher is one thing, but when I actually schedule it in the appliance, I need to tell it how many hours from now it should start the cycle. To calculate this, we can create another Template Sensor with this code:

{% set future_windows = state_attr('binary_sensor.dishwasher_cheapest_window', 'data') | selectattr('start_time', 'gt', now().timestamp() | timestamp_local) | list %}
{% if future_windows %}
  {% set time_till_start = (strptime(future_windows[0]['start_time'], '%Y-%m-%dT%H:%M:%S%z') - now()).total_seconds() %}
  {{ '{:02}:{:02}'.format((time_till_start / 3600) | int, ((time_till_start % 3600) / 60) | int) }}
{% else %}
  Waiting for new data
{% endif %}

The first few lines are essentially the same. Here's what's happening with the additional bits:

• We parse the start_time just like before using strptime but then also calculate the difference between the start_time and the current time (now()) in seconds, and save it in a new variable this time (time_till_start)
• The next line does three things:
  • It formats the hours and minutes (calculated later on in the line) to have leading zeros if necessary (using {:02}).
  • It divides time_till_start by 3600 to get the number of hours and displays the result as an integer (| int).
  • It divides the remainder of [time_till_start ÷ 3600] (denoted by the %) by 60 to get the minutes and displays the result as an integer.

Again, we do the same thing for the two washing machine sensors, but use end_time. Here's what the 30° Batch Sensor looks like:

{% set future_windows = state_attr('binary_sensor.30deg_batch_cheapest_window', 'data') | selectattr('end_time', 'gt', now().timestamp() | timestamp_local) | list %}
{% if future_windows %}
  {% set next_end = (strptime(future_windows[0]['end_time'], '%Y-%m-%dT%H:%M:%S%z') - now()).total_seconds() %}
  {{ '{:02}:{:02}'.format((next_end / 3600) | int, ((next_end % 3600) / 60) | int) }}
{% else %}
  Waiting for new data
{% endif %}

These are the six sensors that we will use for building our card

Appliance	Sensor (Friendly Name)	Sensor (Entity Name)
Dishwasher	Next Dishwasher Start (Duration)	sensor.dishwasher_start_duration
Dishwasher	Next Dishwasher Start (Time)	sensor.dishwasher_start_time
Washing Machine	Next 30° Batch End (Duration)	sensor.next_30deg_batch_end_duration
Washing Machine	Next 30° Batch End (Time)	sensor.next_30deg_batch_end_time
Washing Machine	Next 60° Batch End (Duration)	sensor.next_60deg_batch_end_duration
Washing Machine	Next 60° Batch End (Time)	sensor.next_60deg_batch_end_time

Card Code

In your dashboard, add a "Vertical Stack", select "Show Code Editor" and paste in:

type: conditional
conditions:
  - condition: or
    conditions:
      - condition: state
        entity: sensor.dishwasher_start_duration
        state_not: Waiting for new data
      - condition: state
        entity: sensor.next_30deg_batch_end_duration
        state_not: Waiting for new data
      - condition: state
        entity: sensor.next_60deg_batch_end_duration
        state_not: Waiting for new data
card:
  type: entities
  title: Appliance Schedules
  state_color: true
  show_header_toggle: false
  entities:
    - type: conditional
      conditions:
        - entity: sensor.dishwasher_start_duration
          state_not: Waiting for new data
      row:
        entity: sensor.dishwasher_start_duration
        name: Dishwasher Start
        icon: mdi:dishwasher
        type: custom:secondaryinfo-entity-row
        secondary_info: '[[ sensor.dishwasher_start_time ]]'
    - type: conditional
      conditions:
        - entity: sensor.next_30deg_batch_end_duration
          state_not: Waiting for new data
      row:
        entity: sensor.next_30deg_batch_end_duration
        name: 30° Batch End
        icon: mdi:washing-machine
        type: custom:secondaryinfo-entity-row
        secondary_info: '[[ sensor.next_30deg_batch_end_time ]]'
    - type: conditional
      conditions:
        - entity: sensor.next_60deg_batch_end_duration
          state_not: Waiting for new data
      row:
        entity: sensor.next_60deg_batch_end_duration
        name: 60° Batch End
        icon: mdi:washing-machine
        type: custom:secondaryinfo-entity-row
        secondary_info: '[[ sensor.next_60deg_batch_end_time ]]'