mirror of
https://github.com/RobTillaart/Arduino.git
synced 2024-10-03 18:09:02 -04:00
115 lines
4.4 KiB
Markdown
115 lines
4.4 KiB
Markdown
|
|
[](https://github.com/marketplace/actions/arduino_ci)
|
|
[](https://github.com/RobTillaart/I2C_24LC1025/actions/workflows/arduino-lint.yml)
|
|
[](https://github.com/RobTillaart/I2C_24LC1025/actions/workflows/jsoncheck.yml)
|
|
[](https://github.com/RobTillaart/I2C_24LC1025/blob/master/LICENSE)
|
|
[](https://github.com/RobTillaart/I2C_24LC1025/releases)
|
|
|
|
|
|
# I2C_24LC1025 - I2C 1MB EEPROM
|
|
|
|
Arduino library for for external I2C EEPROM - 24LC1025 and equivalents e.g. 24AA1025/24FC1025.
|
|
|
|
|
|
## Description
|
|
|
|
This library is to access external I2C EEPROM of 128 KB in size,
|
|
typically the 24LC1025 and equivalents e.g. 24AA1025/24FC1025.
|
|
|
|
**Warning**
|
|
A2 = Non-Configurable Chip Select.
|
|
This pin must be connected to VCC (+5V).
|
|
The device will **NOT** work when this pin floats or is connected to GND (0V).
|
|
|
|
|
|
## Interface
|
|
|
|
The interface is kept quite identical to the I2C_EEPROM library.
|
|
https://github.com/RobTillaart/I2C_EEPROM
|
|
|
|
Most important change is 32 bit memory addresses.
|
|
|
|
|
|
### Constructor
|
|
|
|
- **I2C_24LC1025(uint8_t deviceAddress, TwoWire \*wire = &Wire)** constructor, optional Wire interface.
|
|
- **bool begin()** initializes the I2C bus and checks if the device is available on the I2C bus.
|
|
- **bool begin(uint8_t sda, uint8_t scl)** idem for ESP32 / ESP8266 and alike.
|
|
- **bool isConnected()** test to see if device is on the bus.
|
|
|
|
|
|
### Write functions
|
|
|
|
- **int writeByte(uint32_t memoryAddress, uint8_t value)** write a single byte to the specified memory address.
|
|
Returns I2C status, 0 = OK.
|
|
- **int writeBlock(uint32_t memoryAddress, uint8_t \* buffer, uint32_t length)** write a buffer starting at the specified memory address.
|
|
Returns I2C status, 0 = OK.
|
|
- **int setBlock(uint32_t memoryAddress, uint8_t value, uint32_t length)** writes the same byte to length places starting at the specified memory address.
|
|
Returns I2C status, 0 = OK.
|
|
|
|
|
|
### Update functions
|
|
|
|
- **int updateByte(uint32_t memoryAddress, uint8_t value)** write a single byte, but only if changed.
|
|
Returns 0 if value was same or write succeeded.
|
|
- **uint32_t updateBlock(uint32_t memoryAddress, uint8_t \* buffer, uint32_t length)** write a buffer starting at the specified memory address, but only if changed.
|
|
Returns bytes written.
|
|
|
|
|
|
### Read functions
|
|
|
|
- **uint8_t readByte(uint32_t memoryAddress)** read a single byte from a given address
|
|
- **uint32_t readBlock(uint32_t memoryAddress, uint8_t \* buffer, uint32_t length)** read length bytes into buffer starting at specified memory address. Returns the number of bytes read, which should be length.
|
|
|
|
|
|
### Verify functions
|
|
|
|
Since 0.2.0 - experimental, needs extensive testing.
|
|
|
|
Same as write and update functions above. Returns true if successful, false indicates an error.
|
|
|
|
- **bool writeByteVerify(uint32_t memoryAddress, uint8_t value)**
|
|
- **bool writeBlockVerify(uint32_t memoryAddress, uint8_t \* buffer, uint32_t length)**
|
|
- **bool setBlockVerify(uint32_t memoryAddress, uint8_t value, uint32_t length)**
|
|
- **bool updateByteVerify(uint32_t memoryAddress, uint8_t value)**
|
|
- **bool updateBlockVerify(uint32_t memoryAddress, uint8_t \* buffer, uint32_t length)**
|
|
|
|
|
|
### Other
|
|
|
|
- **uint32_t getDeviceSize()** idem
|
|
- **uint8_t getPageSize()** idem
|
|
- **uint32_t getLastWrite()** idem
|
|
|
|
|
|
#### UpdateBlock()
|
|
|
|
(new since 0.1.3)
|
|
|
|
The function **updateBlock()** reads the block of data and compares it with the new values
|
|
to see if it needs rewriting.
|
|
|
|
As the function reads/writes the data in blocks with a maximum length of **I2C_TWIBUFFERSIZE**
|
|
(== 30 AVR limitation; 128 for ESP32) it does this comparison in chuncks if the length exceeds this number.
|
|
The result is that an **updateBlock()** call can result e.g. in 4 reads and only 2 writes under the hood.
|
|
|
|
If data is changed often between writes, **updateBlock()** is slower than **writeBlock()**.
|
|
So you should verify if your sketch can make use of the advantages of **updateBlock()**
|
|
|
|
|
|
## Limitation
|
|
|
|
The library does not offer multiple EEPROMS as one continuous storage device.
|
|
|
|
|
|
## Future
|
|
|
|
- See I2C EEPROM as this library is following.
|
|
- add examples
|
|
|
|
|
|
## Operation
|
|
|
|
See examples
|
|
|