EEPROM Library Compatibility
Store small values in the Uno’s 1 KB nonvolatile memory.
- Pinned version
- 2.0
- Last matching compile evidence
- 2026-10-25
- Toolchain
- avr-gcc-wasm@0.2.0
- Primary headers
- EEPROM.h
Dependencies and practical limits
Store small values in the Uno’s 1 KB nonvolatile memory.
EEPROM capacity is a board property; do not assume Uno’s 1 KB applies to every AVR.
The example compiles read/write operations. Avoid unnecessary repeated writes on real EEPROM, which has finite write endurance.
No additional catalog dependencies are required.
For a missing header, first compare the include to the example below. For an undeclared identifier, inspect the first diagnostic and selected board rather than changing every library version.
Board compile matrix
These are recorded compile/link results for the current build and exact source hash. UNTESTED means no matching proof, not an assumed pass. Memory values belong to the listed example and exclude runtime stack/heap or dynamic buffers.
| Board/profile | Result | Flash bytes | Static SRAM bytes | Last tested |
|---|---|---|---|---|
| Arduino Uno R3 — ATmega328P | PASS | 2424 | 188 | 2026-10-25 |
| Arduino Nano V3 — ATmega328P (new bootloader) | PASS | 2424 | 188 | 2026-10-25 |
| Arduino Nano V3 — ATmega328P (old bootloader) | PASS | 2424 | 188 | 2026-10-25 |
| ATmega328PB — 16 MHz | PASS | 2582 | 188 | 2026-10-25 |
| Arduino Mega 2560 — ATmega2560 | PASS | 2788 | 188 | 2026-10-25 |
| Arduino Leonardo — ATmega32U4 · native USB | PASS | 4862 | 152 | 2026-10-25 |
| Arduino Micro — ATmega32U4 · native USB | PASS | 4864 | 152 | 2026-10-25 |
| Arduino Pro Mini — 5 V · 16 MHz | PASS | 2428 | 188 | 2026-10-25 |
| Arduino Pro Mini — 3.3 V · 8 MHz | PASS | 2416 | 188 | 2026-10-25 |
Build: e0f6d304cce4ae0a0989a9b1300cbc1a21a595e5e3e7f57ed0ab3468ecf7940b. Library source hash: f61931295fd3541998b3a11e1e3261e8e4a9ee1dc946fb2f9a112a2b6809b6d7. Compilation does not certify physical peripherals, timing or USB upload.
EEPROM read-write example
This is the actual pinned example available in Circuitera. Pin choices and wiring in a general example use Uno unless otherwise stated; review the selected board reference for other targets.
#include <EEPROM.h>
void setup() {
Serial.begin(9600);
// update() writes only when the value changes. Avoid repeated EEPROM writes.
EEPROM.update(0, 42);
Serial.print(F("Stored value: ")); Serial.println(EEPROM.read(0));
int calibration = 1234;
EEPROM.put(4, calibration);
int restored = 0;
EEPROM.get(4, restored);
Serial.println(restored);
}
void loop() {}
Projects using EEPROM
No validated public tutorial currently uses this library. The example demonstrates compilation; no working simulator peripheral or hardware project is implied.
Upstream source and documentation ↗
Read the test methodology →