getUniqueID

Signatures

• uint64_t SPIFlash::getUniqueID(void)
• uint64_t SPIFram::getUniqueID(void)

What It Is For

Read chip unique identifier when supported by the specific memory device.

Parameters

• No parameters.

Behavior Details

Useful for device fingerprinting, provisioning, and differentiating units in production logs.

Return Semantics

Returns unique ID value, often 0 when unsupported/unavailable.

Failure Behavior

Not all chips implement unique-ID commands; a zero value may reflect unsupported feature rather than total comms failure.

Common Mistakes

• Assuming all chips implement unique ID and treating 0 as guaranteed comm failure.
• Using UID as security/authentication secret without threat modeling.
• Changing provisioning logic without handling unsupported chips.

Choosing Between Similar APIs

• Use getUniqueID() for unit fingerprinting when supported.
• Use JEDEC/manufacturer IDs for chip compatibility, not per-unit identity.
• If UID is unsupported, fall back to app-level provisioning IDs.

Example

uint64_t uid = flash.getUniqueID();
Serial.println((uint32_t)(uid >> 32), HEX);
Serial.println((uint32_t)uid, HEX);