{"product_id":"iotextra-octal3","title":"IoTextra Octal3 — Digital I\/O with Latching Relay Module","description":"\u003c!-- IoTextra Octal3 — Shopify Product Card --\u003e\n\u003cp\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e\u003c!-- OVERVIEW_START --\u003e\n\u003c\/p\u003e\u003cdiv style=\"border-left:4px solid #8f0000;padding:10px 14px;margin:12px 0;background:#fdf2f2;border-radius:0 6px 6px 0\"\u003e\n  \u003cp style=\"margin:0 0 6px;font-weight:600;font-family:'Roboto Condensed',sans-serif;font-size:19px;color:#111111\"\u003eIoTextra Octal3\u003c\/p\u003e\n  \u003cp style=\"margin:0 0 4px;font-family:'Roboto Condensed',sans-serif;font-size:16px;color:#444444\"\u003e4 isolated digital inputs · 4 latching DPDT relays · galvanic isolation · 3750 VRMS\u003c\/p\u003e\n  \u003cp style=\"margin:0 0 4px;font-family:'Roboto Condensed',sans-serif;font-size:16px;color:#444444\"\u003eInputs up to 36 VDC via GPIO · relay contacts 250 VAC \/ 220 VDC \/ 2 A · relay control via I²C → TCA9534A → DRV8837C\u003c\/p\u003e\n  \u003cp style=\"margin:0;font-family:'Roboto Condensed',sans-serif;font-size:14px;color:#888888\"\u003ePart of the IoTextra series · compatible with IoTsmart and IoTbase · Open Hardware\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c!-- OVERVIEW_END --\u003e\n\u003cp\u003e\u003c!-- BADGES_START --\u003e\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0860\/7481\/8846\/files\/5-logo.svg?v=1787561494\" style=\"max-width:1000px;width:100%;height:auto\"\u003e\n\u003c!-- BADGES_END --\u003e\u003c\/p\u003e\n\n\u003cp\u003e\u003cimg src=\"https:\/\/raw.githubusercontent.com\/makethingshappy\/IoTextra-Digital\/main\/Octal3\/latching.svg\"\u003e\u003c\/p\u003e\n\u003cp style=\"font-family: 'Roboto Condensed',sans-serif; font-size: 15px; color: #333333; line-height: 1.5;\"\u003eThis module is a member of the \u003ca href=\"https:\/\/makethingshappy.io\/collections\/iotextra\" title=\"IoTextra series (analog, digital, and combined I\/O)\"\u003e\u003cstrong\u003eIoTextra\u003c\/strong\u003e\u003c\/a\u003e series, which serves as a fundamental building block of our ecosystem and embodies the \u003ca title=\"Learn more about the Make Things Happy modular ecosystem philosophy\" href=\"https:\/\/makethingshappy.io\/pages\/platform-philosophy-from-prototype-to-industrial-series\"\u003e\u003cstrong\u003eMake Things Happy Philosophy\u003c\/strong\u003e\u003c\/a\u003e. It is engineered to bridge the gap between rapid prototyping and industrial-grade reliability.\u003c\/p\u003e\n \n\u003cp style=\"font-family: 'Roboto Condensed',sans-serif; font-size: 15px; color: #333333; line-height: 1.5;\"\u003e\u003cstrong\u003eHardware Synergy:\u003c\/strong\u003e The module is compatible with both \u003ca href=\"https:\/\/makethingshappy.io\/collections\/iotsmart\" title=\"IoTsmart SoM Controllers (RP2040\/RP2350\/ESP32) for IoT, Smart Home \u0026amp; Automation\"\u003e\u003cstrong\u003eIoTsmart\u003c\/strong\u003e\u003c\/a\u003e and \u003ca title=\"IoTbase carrier modules. Integrate PICO\/Nano with IoTextra digital \u0026amp; analog mezzanines.\" href=\"https:\/\/makethingshappy.io\/collections\/iotbase\"\u003e\u003cstrong\u003eIoTbase\u003c\/strong\u003e\u003c\/a\u003e series.\u003c\/p\u003e\n \n\u003cp style=\"font-family: 'Roboto Condensed',sans-serif; font-size: 15px; color: #333333; line-height: 1.5;\"\u003e\u003cstrong\u003eSoftware Power:\u003c\/strong\u003e This hardware compatibility unlocks the full potential of the \u003ca title=\"Discover how IoTflow integrates hardware with Node-RED and MQTT\" href=\"https:\/\/makethingshappy.io\/pages\/iotflow\"\u003e\u003cstrong\u003eIoTflow\u003c\/strong\u003e\u003c\/a\u003e platform, with native support for \u003cstrong\u003eTasmota\u003c\/strong\u003e and \u003cstrong\u003eHome Assistant\u003c\/strong\u003e as well. It enables you to:\u003c\/p\u003e\n\u003cul style=\"font-family: 'Roboto Condensed',sans-serif; font-size: 15px; color: #333333; line-height: 1.6; margin: 0 0 16px;\"\u003e\n\u003cli\u003eCreate custom \u003cstrong\u003eNode-RED\u003c\/strong\u003e nodes effortlessly.\u003c\/li\u003e\n\u003cli\u003eIntegrate via \u003cstrong\u003eMQTT\u003c\/strong\u003e with third-party global platforms like \u003cstrong\u003eBlynk\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli\u003eScale your project from a single node to a complex industrial network.\u003c\/li\u003e\n\u003c\/ul\u003e\n \n\u003cp style=\"font-family: 'Roboto Condensed',sans-serif; font-size: 15px; color: #333333; line-height: 1.5;\"\u003e\u003cstrong\u003eKey Specifications\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul style=\"font-family: 'Roboto Condensed',sans-serif; font-size: 15px; color: #333333; line-height: 1.7;\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eConfiguration:\u003c\/strong\u003e 4 digital inputs, 4 latching DPDT (2 Form C) relays (KEMET EC2-5SNU)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIsolation:\u003c\/strong\u003e individual galvanic isolation per channel, 3750Vrms dielectric strength\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDigital inputs:\u003c\/strong\u003e up to 36VDC; logic thresholds 0–2V (logical \"1\"), 4–36V (logical \"0\"); read directly via AP0–AP3 on the HOST connector\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRelays:\u003c\/strong\u003e bistable\/latching, retain state without coil power — no heat, no holding current, no unexpected switching on power failure. Switching capacity 2A at 250VAC\/220VDC\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRelay driver:\u003c\/strong\u003e TI DRV8837C H-bridge, generates the polarity-reversal pulse, built-in flyback protection, no external diodes required\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRelay control:\u003c\/strong\u003e via I²C through the onboard TCA9534A expander; the shared nSLEEP signal (AP5) must be driven High before a switching pulse and returned Low afterwards to enable the DRV8837C drivers\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRelay state readback:\u003c\/strong\u003e not available in hardware — the microcontroller must store relay state in EEPROM\/flash and restore it on boot\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eI²C addressing:\u003c\/strong\u003e DIP-switch (A0–A2), up to 16 modules on one bus (each requiring its own or a shared nSLEEP signal)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConnectors:\u003c\/strong\u003e HOST, Qwiic × 2\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStatus indication:\u003c\/strong\u003e LED per digital input channel, LED per relay (LD_K1–K4)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSize:\u003c\/strong\u003e 47 × 56 mm, with mounting holes for base-module or Raspberry Pi installation\u003c\/li\u003e\n\u003c\/ul\u003e\n \n\u003cp style=\"font-family: 'Roboto Condensed',sans-serif; font-size: 15px; color: #333333; line-height: 1.5;\"\u003e\u003cstrong\u003eOperation Modes\u003c\/strong\u003e\u003c\/p\u003e\n\u003cdiv style=\"display:flex; gap:16px; flex-wrap:wrap; margin-bottom:16px;\"\u003e\n\u003cdiv style=\"flex:1; min-width:200px; background:#f7f9fc; border-radius:8px; padding:16px; font-family: 'Roboto Condensed',sans-serif; font-size: 15px; color: #333333;\"\u003e\n\u003cdiv style=\"font-size:18px; margin-bottom:6px;\"\u003e🔌 \u003cstrong\u003eStandalone\u003c\/strong\u003e\n\u003c\/div\u003e\nConnect via the HOST connector cable or Qwiic I²C connectors from any host microcontroller.\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1; min-width:200px; background:#f7f9fc; border-radius:8px; padding:16px; font-family: 'Roboto Condensed',sans-serif; font-size: 15px; color: #333333;\"\u003e\n\u003cdiv style=\"font-size:18px; margin-bottom:6px;\"\u003e🧠 \u003cstrong\u003eSmart\u003c\/strong\u003e\n\u003c\/div\u003e\nAn IoTsmart module is inserted vertically into the HOST connector. Input reading, relay control, and the 5V module supply are provided through HOST, powered from the IoTsmart module.\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1; min-width:200px; background:#f7f9fc; border-radius:8px; padding:16px; font-family: 'Roboto Condensed',sans-serif; font-size: 15px; color: #333333;\"\u003e\n\u003cdiv style=\"font-size:18px; margin-bottom:6px;\"\u003e🏗 \u003cstrong\u003eMezzanine\u003c\/strong\u003e\n\u003c\/div\u003e\nThe module is installed into an IoTbase carrier board. Input reading, relay control, and the 5V module supply are provided through HOST.\n\u003c\/div\u003e\n\u003c\/div\u003e\n \n\u003cp style=\"font-family: 'Roboto Condensed',sans-serif; font-size: 15px; color: #333333; line-height: 1.5; margin-top: 20px;\"\u003e\u003cstrong\u003eApplications\u003c\/strong\u003e\u003c\/p\u003e\n \n\u003cdiv style=\"border-bottom:1px solid #e8edf5; padding:12px 0; font-family: 'Roboto Condensed',sans-serif;\"\u003e\n\u003cspan style=\"display:inline-block; width:40px; height:40px; line-height:40px; text-align:center; border-radius:8px; background:#FAEEDA; color:#854F0B; font-size:20px;\"\u003e⚡\u003c\/span\u003e\n\u003cstrong style=\"font-size: 15px; color: #111111;\"\u003eIIoT — Control Cabinet Management\u003c\/strong\u003e\u003cbr\u003e\n\u003cspan style=\"font-size: 14px; color: #444444;\"\u003eDigital inputs monitor circuit breakers and voltage presence; latching relays hold contactors or disconnect switches through power outages with zero coil energy consumption.\u003c\/span\u003e\n\u003c\/div\u003e\n \n\u003cdiv style=\"border-bottom:1px solid #e8edf5; padding:12px 0; font-family: 'Roboto Condensed',sans-serif;\"\u003e\n\u003cspan style=\"display:inline-block; width:40px; height:40px; line-height:40px; text-align:center; border-radius:8px; background:#E6F1FB; color:#185FA5; font-size:20px;\"\u003e📡\u003c\/span\u003e\n\u003cstrong style=\"font-size: 15px; color: #111111;\"\u003eTelecommunications — Bypass \u0026amp; Line Switching\u003c\/strong\u003e\u003cbr\u003e\n\u003cspan style=\"font-size: 14px; color: #444444;\"\u003ePhysical bypass switching of backup lines; relays remain in position indefinitely without holding current — critical for equipment running continuously for years.\u003c\/span\u003e\n\u003c\/div\u003e\n \n\u003cdiv style=\"border-bottom:1px solid #e8edf5; padding:12px 0; font-family: 'Roboto Condensed',sans-serif;\"\u003e\n\u003cspan style=\"display:inline-block; width:40px; height:40px; line-height:40px; text-align:center; border-radius:8px; background:#E1F5EE; color:#0F6E56; font-size:20px;\"\u003e🌱\u003c\/span\u003e\n\u003cstrong style=\"font-size: 15px; color: #111111;\"\u003eSmart Farming — Irrigation Control\u003c\/strong\u003e\u003cbr\u003e\n\u003cspan style=\"font-size: 14px; color: #444444;\"\u003eMonitor water level sensors and valve limit switches; activate irrigation valves with a short pulse and hold open with zero energy — ideal for solar-powered installations.\u003c\/span\u003e\n\u003c\/div\u003e\n \n\u003cdiv style=\"padding:12px 0; font-family: 'Roboto Condensed',sans-serif;\"\u003e\n\u003cspan style=\"display:inline-block; width:40px; height:40px; line-height:40px; text-align:center; border-radius:8px; background:#EEEDFE; color:#534AB7; font-size:20px;\"\u003e🏠\u003c\/span\u003e\n\u003cstrong style=\"font-size: 15px; color: #111111;\"\u003eSmart Home — Blinds, Gates \u0026amp; Dampers\u003c\/strong\u003e\u003cbr\u003e\n\u003cspan style=\"font-size: 14px; color: #444444;\"\u003eConnect position sensors and manual buttons to inputs; relays retain last position after a power cut — no unexpected movement on power restoration.\u003c\/span\u003e\n\u003c\/div\u003e\n","brand":"Make Things Happy!","offers":[{"title":"HOST-12 and Qwiic (I2C)","offer_id":59709880336670,"sku":"040304302311","price":28.0,"currency_code":"USD","in_stock":true},{"title":"HOST-12","offer_id":59709880369438,"sku":"040304302309","price":27.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0860\/7481\/8846\/files\/01_-_IoTextra_Octal3_-_3D_view.png?v=1785418996","url":"https:\/\/makethingshappy.io\/products\/iotextra-octal3","provider":"Make Things Happy!","version":"1.0","type":"link"}