Hi,
I need a relay board and I’m thinking about building an esp32 based board or buying a ready made one but I have a concern. I had a 12 channel tuya wifi relay board in the past and that showed up as 13 devices essential saturating my wifi network.
This experience made me shun all wifi device for home automatization and went all ZigBee.
Apparently, it’s pretty hard to find or build a ZigBee board that meets my needs so I’m back at 1².
If I build or simply buy an esp32 based relay board or this board to use in homeassistant will that saturate my wifi network or will that show up as one device?
I need a relay board that (preferably 16ch) have connectors for extrnal switches. I need to control the relays with the switches and from homeassistant too.
I’ve found a ZigBee relay board that does this but it doesn’t allow online control when the board set to toggle switch mode. It only allows push buttons and online control to work together.
This is a tuya board so modifying the code or flashing the chip is sort of difficult.
It’s doable with esp32 (for up to 13+13 i/o) but obviously you need relay board that has sufficient number of relays for your approach. What are you switching?
12dc. Led lights, mp3 players, electric locks, maybe raspberries.
I’m thinking about this board: https://a.aliexpress.com/_Ey4haa0 this also has Ethernet connection which is a bonus.
With two random 8ch relay boards so I can easily switch relay boards if necessary.
Yeah, but those relay boards cost next to nothing. If there are no drawbacks then it’s safer to use relays than connecting directly to the board, right?
What I could gather the built in MOSFET are rated 500mA. This should be enough for my LEDs but the raspberry requires a 3A power source so that’s probably too much…
Those mosfets are actually rated max 10A, but I wouldn’t go anywhere near that because of heat dissipation and PCB traces. Can you find some official rating from Kinkony, datasheet?
So use relays if you need higher loads.
The beauty of relays is complete isolation between your control circuit and the device being switched. It is simple, emulating an on/off switch.
Not sure about WiFi traffic - if you have 12 channels, you have twelve devices to control, regardless of the protocol you are communicating with, WiFi or ZigBee. The traffic should be minimal, just the switching part commands and their response. Maybe your integration is polling instead of just issuing commands when states are being changed? A little over-chatty?
It looks like the need is for just switching on/off power on each channel, rather than any analog control. Given the devices being switched, their power requirements are easily accomodated by relays, and you don’t have to worry about power-on surges, etc.
Adding a multichannel relay board to an ESP32 device is fairly straightforward and both devices are Tasmota/ESPHome compatible.
In any case every load has to be considered individually. Chinese “songle-bells” relays for example don’t have any rating for inductive loads and snubbers are likely needed for beefier ones.
one other thing to consider with relay is the clicking noise. Depending on the location of the board and how often you are switching them. It could be annoying with all the clickings.
The Raspberry Pi would probably not enjoy abrupt power off without clean shutdown. Incorporate that shutdown process in your shutdown procedures before [logically] pulling the plug for it. File corruption is a real possibility.
Conversely, at power up time, it takes a little time for it to start the operating system before it is available for use.
Are your electric locks fail-safe with power off? Not fail-open?
Are you just trying to save a few watts of annual power consumption by turning these devices off, but ignoring the similar power requirements of having an IOT device needed to implement switching? Most of these devices you have listed draw minimal power in standby mode.
How long are your cable runs going to be to each device being switched?
I’m not understanding your use case requirements well.
. And this board seems to have optoisolation on all inputs and outputs.