tweak

Author: thinkyhead

Marlin/src/HAL/shared/eeprom_if_i2c.cpp

@@ -61,23 +61,24 @@ static constexpr uint8_t eeprom_device_address = I2C_ADDRESS(EEPROM_DEVICE_ADDRE
 // Public functions
 // ------------------------
 
+#define SMALL_EEPROM (MARLIN_EEPROM_SIZE <= 2048)
+
+// Combine Address high bits into the device address on <=16Kbit (2K) and >512Kbit (64K) EEPROMs.
+// Note: MARLIN_EEPROM_SIZE is specified in bytes, whereas EEPROM model numbers refer to bits.
+//       e.g., The "16" in BL24C16 indicates a 16Kbit (2KB) size.
 static uint8_t _eeprom_calc_device_address(uint8_t * const pos) {
   const unsigned eeprom_address = (unsigned)pos;
-  // Note: MARLIN_EEPROM_SIZE is specified in bytes, whereas most EEPROMs advertise bits
-  if (MARLIN_EEPROM_SIZE <= 2048 || MARLIN_EEPROM_SIZE > 65536) {
-    // Address high bits are stuffed into device address on <=16Kbit and >512Kbit EEPROMs
-    return uint8_t(eeprom_device_address | ((eeprom_address >> (MARLIN_EEPROM_SIZE <= 2048 ? 8 : 16)) & 0x07));
-  }
-  return eeprom_device_address;
+  return (SMALL_EEPROM || MARLIN_EEPROM_SIZE > 65536)
+    ? uint8_t(eeprom_device_address | ((eeprom_address >> (SMALL_EEPROM ? 8 : 16)) & 0x07))
+    : eeprom_device_address;
 }
 
 static void _eeprom_begin(uint8_t * const pos) {
   const unsigned eeprom_address = (unsigned)pos;
   Wire.beginTransmission(_eeprom_calc_device_address(pos));
-  if (MARLIN_EEPROM_SIZE > 2048) {
-    Wire.write(uint8_t((eeprom_address >> 8) & 0xFF)); // Address High, if needed
-  }
-  Wire.write(uint8_t(eeprom_address & 0xFF)); // Address Low
+  if (!SMALL_EEPROM)
+    Wire.write(uint8_t((eeprom_address >> 8) & 0xFF));  // Address High, if needed
+  Wire.write(uint8_t(eeprom_address & 0xFF));           // Address Low
 }
 
 void eeprom_write_byte(uint8_t *pos, uint8_t value) {