diff --git a/src/SparkFun_External_EEPROM.cpp b/src/SparkFun_External_EEPROM.cpp
index 9c62ca4..377e80c 100644
--- a/src/SparkFun_External_EEPROM.cpp
+++ b/src/SparkFun_External_EEPROM.cpp
@@ -296,46 +296,58 @@ uint8_t ExternalEEPROM::detectAddressBytes()
uint32_t originalMemorySize = settings.memorySize_bytes;
uint16_t originalPageSize = settings.pageSize_bytes;
- // Read and store before we start (potentially) writing
- // This will fail on two byte address EEPROMs when the memory size is below 4096 bytes
- uint8_t locationValueOriginal = read(testLocation);
-
- // Serial.print("locationValueOriginal: 0x");
- // Serial.print(locationValueOriginal, HEX);
-
setMemorySizeBytes(128); // Assume the smallest memory size during test
setPageSizeBytes(1); // Assume a page size
+ uint8_t locationValueOriginal = 0;
+
uint8_t addressBytes = 1;
for (; addressBytes < 3; addressBytes++)
{
setAddressBytes(addressBytes); // Start test at one byte
- // Avoid the default state of 0xFF = 255 and 0. Assumes user has randomSeed()ed something.
- // Do not use the original value
- // Do not use the value found in the next location either
- uint8_t magicValue = 0;
- do
+ // Read and store before we start (potentially) writing
+ // This will fail on two byte address EEPROMs when the memory size is below 4096 bytes
+ uint8_t i2cResponse = read(testLocation, &locationValueOriginal, 1);
+
+ // Check to see if the device ACK'd
+ if (i2cResponse == 0)
{
- magicValue = random(1, 255); // (Inclusive, exclusive)
- } while (magicValue == locationValueOriginal);
+ // Serial.print("locationValueOriginal: 0x");
+ // Serial.print(locationValueOriginal, HEX);
+
+ // Avoid the default state of 0xFF = 255 and 0. Assumes user has randomSeed()ed something.
+ // Do not use the original value
+ // Do not use the value found in the next location either
+ uint8_t magicValue = 0;
+ do
+ {
+ magicValue = random(1, 255); // (Inclusive, exclusive)
+ } while (magicValue == locationValueOriginal);
- // Serial.print(" writing: 0x");
- // Serial.print(magicValue, HEX);
+ // Serial.print(" writing: 0x");
+ // Serial.print(magicValue, HEX);
- // Write this new value
- write(testLocation, magicValue); // Will use a 1 or 2 byte address depending on setMemorySizeBytes()
+ // Write this new value
+ write(testLocation, magicValue); // Will use a 1 or 2 byte address depending on setMemorySizeBytes()
- // Read data back
- uint8_t locationValue = read(testLocation);
- // Serial.print(" read: 0x");
- // Serial.print(locationValue, HEX);
- // Serial.print(" - ");
+ // Read data back
+ uint8_t locationValue = read(testLocation);
+ // Serial.print(" read: 0x");
+ // Serial.print(locationValue, HEX);
+ // Serial.print(" - ");
- if (locationValue == magicValue)
+ if (locationValue == magicValue)
+ {
+ // Successful write. We've determined the number of address bytes
+ break;
+ }
+ }
+ else
{
- // Successful write. We've determined the number of address bytes
- break;
+ // Serial.print(" device failed ack with: ");
+ // Serial.print(i2cResponse);
+ // Serial.println(". Moving to next address byte size.");
}
}
@@ -411,14 +423,6 @@ uint16_t ExternalEEPROM::detectPageSizeBytes()
// Serial.print(pageSizeBytes);
// Serial.print(" write failed. Previous page size is the answer ");
- // Reduce the page size to the last value
- if (pageSizeBytes == 32 || pageSizeBytes == 16 || pageSizeBytes == 256)
- pageSizeBytes /= 2;
- else if (pageSizeBytes == 128)
- pageSizeBytes = 32;
- else if (pageSizeBytes == 8)
- pageSizeBytes = 1;
-
detectedPageSize = true;
break;
@@ -437,10 +441,12 @@ uint16_t ExternalEEPROM::detectPageSizeBytes()
pageSizeBytes *= 2;
else if (pageSizeBytes == 32)
pageSizeBytes = 128;
- else if (pageSizeBytes == maxPageSize)
+ else if (pageSizeBytes > maxPageSize)
break; // EEPROMs with larger than 256 byte page writes are not known at this time.
- // We can't write more than I2C_BUFFER_LENGTH_TX at a time so that is the limit of our pageSize testing.
+ // The I2C_BUFFER_LENGTH of this platform must be large enough for the pageSizeBytes + deviceID byte + address byte(s).
+ // For example, if the page size is 32, we need a buffer that is 34 bytes. However, many platforms (ie Uno) have only
+ // 32 bytes. We therefor have to give up and use page writes up to the size of I2C_BUFFER_LENGTH_TX.
if (pageSizeBytes > I2C_BUFFER_LENGTH_TX)
{
// Serial.print("Page size test limited by platform I2C buffer of: ");
@@ -449,33 +455,41 @@ uint16_t ExternalEEPROM::detectPageSizeBytes()
}
}
+ // Reduce the page size to the last value
+ if (pageSizeBytes == 32 || pageSizeBytes == 16 || pageSizeBytes == 256 || pageSizeBytes == 512)
+ pageSizeBytes /= 2;
+ else if (pageSizeBytes == 128)
+ pageSizeBytes = 32;
+ else if (pageSizeBytes == 8)
+ pageSizeBytes = 1;
+
settings.pageSize_bytes = pageSizeBytes;
// Write original chunk to EEPROM
- write(testLocation, originalValuesArray, pageSizeBytes);
+ write(testLocation, originalValuesArray, maxPageSize);
return (settings.pageSize_bytes);
}
// Attempts write-then-reads until failure to determine memory bounds
// Identifies the following EEPROM types and their variants:
-// 24LC00 - 128 bit / 16 bytes - 1 address byte, 1 byte page size
-// 24LC01 - 1024 bit / 128 bytes - 1 address byte, 8 byte page size
-// 24LC02 - 2048 bit / 256 bytes - 1 address byte, 8 byte page size
-// 24LC04 - 4096 bit / 512 bytes - 1 address byte, 16 byte page size
-// 24LC08 - 8192 bit / 1024 bytes - 1 address byte, 16 byte page size
-// 24LC16 - 16384 bit / 2048 bytes - 1 address byte, 16 byte page size
-// 24LC32 - 32768 bit / 4096 bytes - 2 address bytes, 32 byte page size
-// 24LC64 - 65536 bit / 8192 bytes - 2 address bytes, 32 byte page size
-// 24LC128 - 131072 bit / 16384 bytes - 2 address bytes, 64 byte page size
-// 24LC256 - 262144 bit / 32768 bytes - 2 address bytes, 64 byte page size
-// 24LC512 - 524288 bit / 65536 bytes - 2 address bytes, 128 byte page size
-// 24LC1024 - 1024000 bit / 128000 byte - 2 address bytes, 128 byte page size
-// 24CM02 - 2097152 bit / 262144 byte - 2 address bytes, 256 byte page size
+// 24XX00 - 128 bit / 16 bytes - 1 address byte, 1 byte page size
+// 24XX01 - 1024 bit / 128 bytes - 1 address byte, 8 byte page size
+// 24XX02 - 2048 bit / 256 bytes - 1 address byte, 8 byte page size
+// 24XX04 - 4096 bit / 512 bytes - 1 address byte, 16 byte page size
+// 24XX08 - 8192 bit / 1024 bytes - 1 address byte, 16 byte page size
+// 24XX16 - 16384 bit / 2048 bytes - 1 address byte, 16 byte page size
+// 24XX32 - 32768 bit / 4096 bytes - 2 address bytes, 32 byte page size
+// 24XX64 - 65536 bit / 8192 bytes - 2 address bytes, 32 byte page size
+// 24XX128 - 131072 bit / 16384 bytes - 2 address bytes, 64 byte page size
+// 24XX256 - 262144 bit / 32768 bytes - 2 address bytes, 64 byte page size
+// 24XX512 - 524288 bit / 65536 bytes - 2 address bytes, 128 byte page size
+// 24XX1024 - 1024000 bit / 128000 byte - 2 address bytes, 128 byte page size
+// 24XXM02 - 2097152 bit / 262144 byte - 2 address bytes, 256 byte page size
// For EEPROMs of 4k, 8k, and 16k bit, there are three bits called
// 'block select bits' inside the address byte that are used
// For 32k, 64k, 128k, 256k, and 512k bit we need two address bytes
-// At 1Mbit (128,000 byte) and above there are two address bytes and a block select bit
+// At 1Mbit (128,000 byte) and above there are two address bytes and a block select bit
// is used but at the upper end of the address bits (so instead of A2/A1/A0 it's B0/A1/A0).
uint32_t ExternalEEPROM::detectMemorySizeBytes()
{
@@ -771,7 +785,14 @@ int ExternalEEPROM::write(uint32_t eepromLocation, const uint8_t *dataToWrite, u
settings.i2cPort->write((uint8_t)((eepromLocation + recorded) & 0xFF)); // LSB
for (uint16_t x = 0; x < amtToWrite; x++)
+ {
settings.i2cPort->write(dataToWrite[recorded + x]);
+ // Serial.print("writing: ");
+ // Serial.print(dataToWrite[recorded + x]);
+ // Serial.print(" to location: ");
+ // Serial.print(eepromLocation + recorded + x);
+ // Serial.println();
+ }
result = settings.i2cPort->endTransmission(); // Send stop condition
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