This month's ranking
Automation building blocks for custom-built irrigation projects.
A cheap entry point for controlling a single valve or pump from a microcontroller (Arduino, ESP32, Raspberry Pi). This particular model's listing doesn't confirm optocoupler isolation — before wiring it to a 24V AC load, verify that with the seller or add a separate optocoupler so you don't risk frying your microcontroller.
With 8 channels you can control up to 8 valves/zones from a single microcontroller — enough to build a complete DIY irrigation controller. It includes an optocoupler (real electrical isolation between the 5V logic and the switched load) and NO/NC terminals, making it safer than a 1-channel module without that isolation confirmed.
Unlike the relays in this ranking (1-channel and 8-channel), which are 'raw' modules meant to connect to an Arduino/ESP32, this one has its own built-in WiFi — you don't need to program anything or add a separate microcontroller, it's controlled directly from the eWeLink app (or Alexa/Google) as soon as you connect it to your network. 2 channels, dry-contact output compatible with 24V, up to 10A.
Unlike the two relay modules in this catalog meant for Arduino programming (the 1-channel one and the ELEGOO 8-channel), this SONOFF is a finished smart switch: it mounts on a DIN rail inside an electrical panel and is controlled via WiFi, app, voice (Alexa/Google), or a 433MHz RF remote, without writing a single line of code. Amazon's Choice, 320 reviews, 4.5 stars. It has an interlock mode (turning on one channel automatically shuts off the other 3) — useful for alternating irrigation zones with no extra logic needed. Real limitation, per Amazon's review summary: several buyers report intermittent WiFi connectivity issues, worth considering if your router is far from the panel.
Unlike this catalog's SONOFF 4CH Pro R3 (4 channels, DIN-rail mounted inside a panel), this Shelly is a tiny single-channel relay meant to be flush-mounted right next to the device it controls — the manufacturer specifically calls out weather-based irrigation automation as a use case. WiFi + Matter, dry contacts, up to 8A, also works as a WiFi range extender. 100+ bought in the past month, 4.5 stars. Real limitation: it ships with no enclosure of its own — the manufacturer itself notes that for use near an irrigation panel it needs a separate waterproof housing, unlike this catalog's plug-and-play DieseRC.
