writeStr

Signatures

• bool SPIFlash::writeStr(uint32_t _addr, String &data, bool errorCheck = true)
• bool SPIFram::writeStr(uint32_t _addr, String &data, bool errorCheck = true)

What It Is For

Write an Arduino String payload to memory in library-defined format.

Parameters

• _addr: Start address for string storage.
• data: Input String to store.
• errorCheck: Optional verification pass after write.

Behavior Details

For robust writes, reserve/erase enough bytes using sizeofStr(data) before writing. This avoids overlap/truncation when string lengths vary.

Return Semantics

Returns true on successful write (and verification when enabled).

Failure Behavior

Failures occur from insufficient erased space (flash), invalid address range, comms errors, or write-protect state.

Common Mistakes

• Writing string data without reserving/erasing sizeofStr(data) bytes first on flash.
• Changing string length over time without updating allocation/erase size.
• Treating String storage as C-string without considering library format.

Choosing Between Similar APIs

• Use writeStr() for Arduino String workflows with variable length.
• Use writeCharArray() for fixed-size or C-string buffers.
• Use writeByteArray() for non-text binary payloads.

Example

String msg = "Hello flash";
uint16_t sz = flash.sizeofStr(msg);
uint32_t addr = flash.getAddress(sz);
flash.eraseSection(addr, sz);
flash.writeStr(addr, msg);