{"product_id":"ds3231-mini-rtc-module","title":"DS3231 Mini High-Precision RTC Module – I2C, Arduino \u0026 Raspberry Pi","description":"\u003cstyle\u003e.nznpd{--o:#F57C00;--od:#E65100;--ink:#0F172A;--mut:#5b6573;--line:#E8ECF0;--soft:#F7F8FA;max-width:1120px;margin:0 auto;color:var(--ink);font-family:inherit;line-height:1.6} .nznpd,.nznpd *{box-sizing:border-box} .nznpd p{margin:0;color:var(--mut);font-size:15px;line-height:1.65} .nznpd strong{color:var(--ink)} .nznpd__intro{font-size:16px;color:var(--ink);font-weight:500;line-height:1.6;max-width:none} .nznpd__checks{list-style:none;padding:0;margin:22px 0 0;display:grid;grid-template-columns:repeat(2,1fr);column-gap:26px;row-gap:13px} .nznpd__checks li{display:flex;gap:11px;align-items:flex-start;font-size:15px;color:var(--ink);line-height:1.45} .nznpd__checks li::before{content:\"\\2713\";flex:0 0 auto;width:21px;height:21px;margin-top:1px;border-radius:999px;background:#FFF3E8;color:var(--o);font-size:12px;font-weight:900;line-height:21px;text-align:center} .nznpd__qs{background:linear-gradient(170deg,#FFF9F3,#FFF1E6);border:2px solid #FCE0C6;border-radius:16px;padding:22px} .nznpd__qs h3{margin:0 0 16px;font-size:12px;font-weight:800;letter-spacing:.09em;text-transform:uppercase;color:var(--od)} .nznpd__steps{list-style:none;counter-reset:s;padding:0;margin:0;display:grid;gap:14px} .nznpd__steps li{display:grid;grid-template-columns:27px 1fr;gap:12px} .nznpd__steps li::before{counter-increment:s;content:counter(s);width:27px;height:27px;border-radius:999px;background:#fff;border:2px solid #FCE0C6;color:var(--od);font-weight:800;font-size:13px;display:flex;align-items:center;justify-content:center} .nznpd__steps strong{display:block;font-size:14px} .nznpd__steps p{font-size:13px;margin-top:2px;line-height:1.45} .nznpd__block{margin-top:36px;padding-top:30px;border-top:1px solid var(--line)} .nznpd__h{margin:0 0 28px;font-size:1.15rem;font-weight:800;letter-spacing:-.02em;color:var(--ink);display:flex;align-items:center;gap:10px} .nznpd__h::before{content:\"\";flex:0 0 auto;width:20px;height:3px;border-radius:2px;background:var(--o)} .nznpd__specs{border:2px solid var(--line);border-radius:12px;overflow:hidden} .nznpd__spec{display:grid;grid-template-columns:minmax(150px,.7fr) 1fr;gap:18px;padding:12px 16px;font-size:14px} .nznpd__spec:nth-child(odd){background:var(--soft)} .nznpd__spec span{color:var(--mut)} .nznpd__spec strong{font-weight:700} .nznpd__included{display:flex;gap:16px;align-items:center;border:2px solid var(--line);border-radius:16px;background:var(--soft);padding:18px 20px} .nznpd__qty{flex:0 0 auto;width:46px;height:46px;border-radius:12px;background:#FFF3E8;color:var(--o);font-weight:800;display:flex;align-items:center;justify-content:center} .nznpd__included strong{display:block;font-size:15px;margin-bottom:3px} .nznpd__uses{display:grid;grid-template-columns:repeat(2,1fr);gap:10px} .nznpd__use{padding:13px 14px;background:var(--soft);border-left:3px solid var(--o);border-radius:0 10px 10px 0;font-size:14px;color:var(--ink);line-height:1.4} .nznpd__faqs{display:grid;gap:10px} .nznpd__faq{border:2px solid var(--line);border-radius:12px;background:#fff;padding:0 16px;transition:border-color .18s ease} .nznpd__faq[open]{border-color:#FCE0C6} .nznpd__faq summary{list-style:none;cursor:pointer;padding:15px 0;font-weight:700;font-size:14px;color:var(--ink);display:flex;justify-content:space-between;align-items:center;gap:12px} .nznpd__faq summary::-webkit-details-marker{display:none} .nznpd__faq summary::after{content:\"\\203A\";flex:0 0 auto;color:var(--o);font-weight:800;font-size:20px;line-height:1;display:inline-block;transform:rotate(90deg);transition:transform .22s ease} .nznpd__faq[open] summary::after{transform:rotate(-90deg)} .nznpd__faq p{padding:0 0 16px;font-size:14px} .nznpd__faq[open] p{animation:nznpdReveal .24s ease} @keyframes nznpdReveal{from{opacity:0;transform:translateY(-5px)}to{opacity:1;transform:translateY(0)}} .nznpd p.nznpd__note{margin-top:16px;background:var(--soft);border:2px solid var(--line);border-radius:12px;padding:14px 16px;font-size:13.5px;color:var(--mut);line-height:1.55} @media (prefers-reduced-motion:reduce){.nznpd__faq summary::after{transition:none}.nznpd__faq[open] p{animation:none}} @media (max-width:749px){.nznpd__checks{grid-template-columns:1fr}.nznpd__uses{grid-template-columns:1fr}.nznpd__spec{grid-template-columns:1fr;gap:2px}}\u003c\/style\u003e\u003cdiv class=\"nznpd\"\u003e\n\u003cdiv class=\"nznpd__lead\"\u003e\n\u003cp class=\"nznpd__intro\"\u003eHigh-precision timekeeping in a tiny footprint. This \u003cstrong\u003emini DS3231\u003c\/strong\u003e module puts a temperature-compensated \u003cstrong\u003eDS3231SN\u003c\/strong\u003e real-time clock on an ultra-compact board — just \u003cstrong\u003e~2.7 g\u003c\/strong\u003e — that plugs straight onto a \u003cstrong\u003eRaspberry Pi\u003c\/strong\u003e's I2C header, and works just as well with Arduino, ESP32 or any I2C microcontroller via jumper wires. It holds time to about \u003cstrong\u003e±0.4 seconds a day\u003c\/strong\u003e (±5 ppm across −40 to +85°C) — a couple of minutes a year, versus the minutes-per-week drift of a DS1307. Built-in temperature sensor, two calendar alarms and a 3.3–5.5V supply. Backup battery not included.\u003c\/p\u003e\n\u003cbr\u003e\u003cul class=\"nznpd__checks\"\u003e\n\u003cli\u003eDS3231SN RTC, temperature-compensated\u003c\/li\u003e\n\u003cli\u003eAccurate to ±5 ppm — about ±0.4 s a day\u003c\/li\u003e\n\u003cli\u003eFar steadier timekeeping than a DS1307\u003c\/li\u003e\n\u003cli\u003eBuilt-in digital temperature sensor (±3°C)\u003c\/li\u003e\n\u003cli\u003eTwo programmable calendar alarms\u003c\/li\u003e\n\u003cli\u003e1 Hz \u0026amp; 32.768 kHz outputs\u003c\/li\u003e\n\u003cli\u003e3.3–5.5V supply, low power\u003c\/li\u003e\n\u003cli\u003eUltra-compact (~2.7 g), plugs onto Raspberry Pi\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003csection class=\"nznpd__block\"\u003e\u003ch3 class=\"nznpd__h\"\u003eSpecifications\u003c\/h3\u003e\n\u003cbr\u003e\u003cdiv class=\"nznpd__specs\"\u003e\n\u003cdiv class=\"nznpd__spec\"\u003e\n\u003cspan\u003eRTC chip\u003c\/span\u003e\u003cstrong\u003eDS3231SN (16-pin SO, 300 mil)\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"nznpd__spec\"\u003e\n\u003cspan\u003eTiming accuracy\u003c\/span\u003e\u003cstrong\u003e±5 ppm (−40 to +85°C), ±0.432 s\/day\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"nznpd__spec\"\u003e\n\u003cspan\u003eTemperature sensor\u003c\/span\u003e\u003cstrong\u003eDigital, ±3°C\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"nznpd__spec\"\u003e\n\u003cspan\u003eCalendar\u003c\/span\u003e\u003cstrong\u003eSec\/min\/hr\/day\/date\/month\/year, leap-year to 2100\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"nznpd__spec\"\u003e\n\u003cspan\u003eAlarms\u003c\/span\u003e\u003cstrong\u003e2 programmable calendar alarms\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"nznpd__spec\"\u003e\n\u003cspan\u003eOutputs\u003c\/span\u003e\u003cstrong\u003e1 Hz \u0026amp; 32.768 kHz\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"nznpd__spec\"\u003e\n\u003cspan\u003eExtras\u003c\/span\u003e\u003cstrong\u003eReset output, button de-bounce input\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"nznpd__spec\"\u003e\n\u003cspan\u003eInterface\u003c\/span\u003e\u003cstrong\u003eI²C, Fast-mode up to 400 kHz (addr 0x68)\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"nznpd__spec\"\u003e\n\u003cspan\u003eOperating voltage\u003c\/span\u003e\u003cstrong\u003e3.3V – 5.5V\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"nznpd__spec\"\u003e\n\u003cspan\u003eOperating temperature\u003c\/span\u003e\u003cstrong\u003e−40°C to +85°C\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"nznpd__spec\"\u003e\n\u003cspan\u003eBackup battery\u003c\/span\u003e\u003cstrong\u003eLIR2032 rechargeable (not included)\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"nznpd__spec\"\u003e\n\u003cspan\u003ePinout\u003c\/span\u003e\u003cstrong\u003e+ (VCC), D (SDA), C (SCL), NC, − (GND)\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"nznpd__spec\"\u003e\n\u003cspan\u003eSize \/ weight\u003c\/span\u003e\u003cstrong\u003eapprox. 22 × 18 mm · ~2.7 g\u003c\/strong\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003csection class=\"nznpd__block\"\u003e\u003ch3 class=\"nznpd__h\"\u003eWhat's in the box\u003c\/h3\u003e\n\u003cbr\u003e\u003cdiv class=\"nznpd__included\"\u003e\n\u003cdiv class=\"nznpd__qty\"\u003e1×\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cstrong\u003eMini DS3231SN high-precision RTC module\u003c\/strong\u003e\u003cp\u003eBackup battery (rechargeable LIR2032) not included — see the FAQ on battery type.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003csection class=\"nznpd__block\"\u003e\u003ch3 class=\"nznpd__h\"\u003eGreat for\u003c\/h3\u003e\n\u003cbr\u003e\u003cdiv class=\"nznpd__uses\"\u003e\n\u003cdiv class=\"nznpd__use\"\u003eRaspberry Pi timekeeping (no network needed)\u003c\/div\u003e\n\u003cdiv class=\"nznpd__use\"\u003eAccurate clocks \u0026amp; alarm projects\u003c\/div\u003e\n\u003cdiv class=\"nznpd__use\"\u003eData loggers with reliable timestamps\u003c\/div\u003e\n\u003cdiv class=\"nznpd__use\"\u003eScheduling relays, lights \u0026amp; automation\u003c\/div\u003e\n\u003cdiv class=\"nznpd__use\"\u003eCompact builds where space is tight\u003c\/div\u003e\n\u003cdiv class=\"nznpd__use\"\u003eUpgrading a DS1307 where accuracy matters\u003c\/div\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003csection class=\"nznpd__block\"\u003e\u003cdiv class=\"nznpd__qs\"\u003e\n\u003ch3\u003eGetting started\u003c\/h3\u003e\n\u003col class=\"nznpd__steps\"\u003e\n\u003cli\u003e\u003cdiv\u003e\n\u003cstrong\u003eConnect it\u003c\/strong\u003e\u003cp\u003eOn a Pi, push it onto the first GPIO header pins so + D C NC − line up. On any MCU, wire +→3.3–5V, D→SDA, C→SCL, −→GND.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cdiv\u003e\n\u003cstrong\u003eFit a coin cell\u003c\/strong\u003e\u003cp\u003eInsert a rechargeable LIR2032 so it keeps time when the power is off.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cdiv\u003e\n\u003cstrong\u003eEnable \/ add a library\u003c\/strong\u003e\u003cp\u003eOn Pi, enable I2C and the DS3231 overlay; on Arduino, use RTClib (DS3231).\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cdiv\u003e\n\u003cstrong\u003eSet the time\u003c\/strong\u003e\u003cp\u003eSet it once — it then keeps accurate time on its own.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003csection class=\"nznpd__block\"\u003e\u003ch3 class=\"nznpd__h\"\u003eCommon questions\u003c\/h3\u003e\n\u003cbr\u003e\u003cdiv class=\"nznpd__faqs\"\u003e\n\u003cdetails class=\"nznpd__faq\" open\u003e\u003csummary\u003eHow accurate is it versus a DS1307?\u003c\/summary\u003e\u003cp\u003eFar steadier. The DS3231SN's temperature-compensated crystal holds time to about ±0.4 seconds a day (±5 ppm) — a couple of minutes a year — where a DS1307 can drift minutes per week. If timekeeping matters, this is the one to use.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails class=\"nznpd__faq\"\u003e\u003csummary\u003eDoes it only work with Raspberry Pi?\u003c\/summary\u003e\u003cp\u003eNo — it's labelled \"for Pi\" because it plugs neatly onto the Pi's I2C header, but it's a standard I2C device. Wire + D C − to VCC \/ SDA \/ SCL \/ GND and it works with Arduino, ESP32 or any microcontroller (3.3–5.5V).\u003c\/p\u003e\u003c\/details\u003e\u003cdetails class=\"nznpd__faq\"\u003e\u003csummary\u003eWhat do the pins mean?\u003c\/summary\u003e\u003cp\u003e+ = VCC (3.3–5.5V), D = SDA (data), C = SCL (clock), NC = not connected, − = GND.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails class=\"nznpd__faq\"\u003e\u003csummary\u003eDoes it have onboard EEPROM?\u003c\/summary\u003e\u003cp\u003eNo — this compact version is RTC-only (no AT24C32 EEPROM, unlike the larger ZS-042 board). If you need extra storage, add a separate EEPROM or use your microcontroller's memory.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails class=\"nznpd__faq\"\u003e\u003csummary\u003eIs the battery included?\u003c\/summary\u003e\u003cp\u003eNo. It takes a rechargeable LIR2032 coin cell (not included); the board has a charging circuit to keep it topped up while powered.\u003c\/p\u003e\u003c\/details\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003cp class=\"nznpd__note\"\u003e\u003cstrong\u003eGood to know:\u003c\/strong\u003e ultra-compact DS3231SN RTC (RTC-only, no EEPROM), takes a rechargeable LIR2032 backup cell (not included). Every order is checked before it ships from our Te Awamutu stock.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"NZN Electronics","offers":[{"title":"Default Title","offer_id":42882594734176,"sku":"MOD-DS3231","price":5.99,"currency_code":"NZD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0664\/6127\/0112\/files\/DS3231SNProductHero.png?v=1781748090","url":"https:\/\/www.nznelectronics.co.nz\/products\/ds3231-mini-rtc-module","provider":"NZN Electronics","version":"1.0","type":"link"}