⚠️ Use the PR version at esphome/esphome#4880, as that may go in esphome and that will be updated in the future.

esphome-fram

ESPHome port of RobTillaart/FRAM_I2C

The code has been adjusted to use ESPHome's implementation of the I2C bus, so the library can be used with both Arduino and ESP-IDF frameworks.

Some features were removed as I don't have use for them (yet) and can (should) be implemented separate of this component.

• removed FRAM_RINGBUFFER and FRAM_ML classes
• removed write protect pin, control that pin elsewhere in esphome
• removed hard-coded size for FRAM9/FRAM11, set the size in yaml

Usage

external_components:
  - source: github://sharkydog/esphome-fram
    components: [ fram ]

i2c:
  scl: 10
  sda: 8
  id: i2c_1

fram:
 - id: fram_1
 - id: fram_2
   i2c_id: i2c_1
   address: 0x52
   type: FRAM11
   size: 2KiB

some_option:
  on_something:
    - lambda: |-
        uint8_t write_bytes[3] = {0xA2,0xB2,0xC2};
        fram_1->write(0x0001, write_bytes, 3);
        
        uint8_t read_bytes[2] = {0,0};
        fram_1->read(0x0002, read_bytes, 2);
        ESP_LOGD("fram","Bytes: 0x%X 0x%X", read_bytes[0], read_bytes[1]);

Multiple devices can be used at the same time.

• id - Unique ID for use in lambdas
• i2c_id - (optional) ID of the I2C bus
• address - (optional, default 0x50) I2C address
• type - (optional, default FRAM) One of: FRAM, FRAM9, FRAM11, FRAM32
• size - (optional) Set the fram size, if your device does not return a size and this is not set, logs will warn you
  • valid option is a number optionally followed by suffix - one of: B, KB, KiB, MB, MiB
  • KB and MB multiply by 1000, KiB and MiB multiply by 1024
  • you won't be able to use clear() method if size is unknown

I only have MB85RC256V, it has no sleep function, so my FRAM9/FRAM11/FRAM32 and FRAM::sleep() are not tested.

Fore more info on methods and supported devices, see RobTillaart/FRAM_I2C/README.md

fram_pref - global_preferences handler

A component that replaces global_preferences, meaning wherever there is a setting "restore from flash" or similar, those states will be written in FRAM.

Tested with a Switch on ESP8266 and ESP32-C3 with ESP-IDF.

All preferences in the pool will be wiped out on reflash.

A more persistant option can be added through static preferences (see bellow). A pool or at least one static preference must be defined, or both.

external_components:
  - source: github://sharkydog/esphome-fram
    components: [ fram, fram_pref ]

i2c:
  scl: 10
  sda: 8
  id: i2c_1

fram:
 - id: fram_1

fram_pref:
  fram_id: fram_1
  pool_size: 1KiB
  pool_start: 100

switch:
  - platform: gpio
    pin: 12
    name: "test switch"
    id: switch_1
    restore_mode: RESTORE_DEFAULT_OFF

• pool_size - (optional) Size of the pool to hold preferences, min 7, max 65536 (64KiB)
• pool_start - (optional, default 0) Starting address for the pool, max 65528

Static preferences

A list of preferences can be added to be kept after reflash. They will not be cleared unless a component changes its internal hash (like changing entity name). If persist_key option is used, the preference will be cleared only if key is changed.

Keep in mind, that if this internal hash changes, the component probably wants its preferences cleared.

fram_pref:
  fram_id: fram_1
  pool_size: 1KiB
  pool_start: 100
  static_prefs:
    - key: sw1
      lambda: return id(switch_1).get_object_id_hash();
      addr: 12
      size: 3
      persist_key: true
    - key: wifi
      lambda: return fnv1_hash(App.get_compilation_time());

• key - (required, string) Unique key for this preference
• lambda - (required) A lambda to return the same hash components use in make_preference() call, most components (entities) use get_object_id_hash(), which is a hash of the name or id.
• addr - (optional, default 0) Starting address
• size - (optional) Size, requested size will be reported in logs
• persist_key - (optional, default false) Persist after hash change, change key to clear

Add either both addr and size or none of them. If they are not added, preference will be ignored and saved nowhere, but reported in logs (so you know what size to set).

Address ranges can not overlap with each other or with the pool (if set).

Logs will report something like this for each preference: Pref: key: sw1, persist_key, addr: 12-14, request size: 3

• If key: sw1 is numeric, preference is in the pool and not static
• persist_key will not be shown if the option above is not used
• addr: 12-14 is start-end address (inclusive) in FRAM, not shown if addr, size and pool were not set, this means preference is ignored
• request size: 3 is the size that needs to be set in size, if this does not show, make_preference() was not called for this hash (returned with lambda)

So, to set a static preference for some component or entity:

• search esphome source for make_preference and see how the hash is being generated.
• put something in lambda that will generate the same.
• compile, upload and look in the logs for your key
• set addr that does not overlap with pool or other preference and size to what is reported with request size: 3
• compile, upload and done