Add support for I2C EEPROMs with page sizes other than 128 in eeprom_i2c.py.

Author: adeuring

eeprom/i2c/eep_i2c.py

@@ -132,8 +132,10 @@ def cptest(eep=None):  # Assumes pre-existing filesystem of either type
             print("Fail mounting device. Have you formatted it?")
             return
         print("Mounted device.")
-    cp("eep_i2c.py", "/eeprom/")
-    cp("eeprom_i2c.py", "/eeprom/")
+    cp(__file__, "/eeprom/")
+    # We may have the source file or a precompiled binary (*.mpy)
+    suffix = __file__[__file__.rfind('.'):]
+    cp("eeprom_i2c" + suffix, "/eeprom/")
     print('Contents of "/eeprom": {}'.format(uos.listdir("/eeprom")))
     print(uos.statvfs("/eeprom"))
 

eeprom/i2c/eeprom_i2c.py

@@ -16,10 +16,18 @@
 T24C64 = const(8192)  # 8KiB 64Kbits
 T24C32 = const(4096)  # 4KiB 32Kbits
 
+_PAGE_SIZES = {
+    T24C32: const(0x20),
+    T24C64: const(0x20),
+    T24C128: const(0x40),
+    T24C256: const(0x40),
+    T24C512: const(0x80),
+    }
+
 # Logical EEPROM device consists of 1-8 physical chips. Chips must all be the
 # same size, and must have contiguous addresses.
 class EEPROM(BlockDevice):
-    def __init__(self, i2c, chip_size=T24C512, verbose=True, block_size=9, addr=_ADDR, max_chips_count=_MAX_CHIPS_COUNT):
+    def __init__(self, i2c, chip_size=T24C512, verbose=True, block_size=9, addr=_ADDR, max_chips_count=_MAX_CHIPS_COUNT, page_size=None):
         self._i2c = i2c
         if chip_size not in (T24C32, T24C64, T24C128, T24C256, T24C512):
             print("Warning: possible unsupported chip. Size:", chip_size)
@@ -29,6 +37,16 @@ def __init__(self, i2c, chip_size=T24C512, verbose=True, block_size=9, addr=_ADD
         self._i2c_addr = 0  # I2C address of current chip
         self._buf1 = bytearray(1)
         self._addrbuf = bytearray(2)  # Memory offset into current chip
+        if page_size is None:
+            if chip_size not in _PAGE_SIZES:
+                raise ValueError(
+                    f'The page size for chip size {chip_size} is not known.'
+                    'Please specify it in the parameter page_size')
+            self._page_mask = ~(_PAGE_SIZES[chip_size] - 1)
+            self._page_size = _PAGE_SIZES[chip_size]
+        else:
+            self._page_mask = ~(page_size - 1)
+            self._page_size = page_size
 
     # Check for a valid hardware configuration
     def scan(self, verbose, chip_size, addr, max_chips_count):
@@ -67,7 +85,7 @@ def _getaddr(self, addr, nbytes):  # Set up _addrbuf and _i2c_addr
         self._addrbuf[0] = (la >> 8) & 0xFF
         self._addrbuf[1] = la & 0xFF
         self._i2c_addr = self._min_chip_address + ca
-        pe = (addr & ~0x7F) + 0x80  # byte 0 of next page
+        pe = (addr & self._page_mask) + self._page_size  # byte 0 of next page
         return min(nbytes, pe - la)
 
     # Read or write multiple bytes at an arbitrary address