Trying to get this relay working. Ive got a level shifter. Do I need anything else?
April 6, 2023, 14:04
Hi. Im trying to get this relay to trigger and I'm concerned I'm not providing enough power to the relay to trigger them. I've got an i2c level shifter thats able to put the voltage from 3.3v to 5v to the relay but the instructions advice that the shifter needs to have a 5v power supply on the HV side. Can I just use a 5v power supply or do I need to find a 5v supply from my Pi 4? The issue is I don't have access to any of the GPIO pins as they are occupied by the HyperPixel Screen.
Parts:
Raspberry Pi 4 4gb
MLink 4 Channel I2C / Parallel Relay Module ( https://hobbycomponents.com/recently-purchased/1090-mlink-4-channel-i2c-parallel-relay-module )
I'm using the Pimoroni breakout connectors for quick release from the relay.
Dont mix the 5v from RPi4 and I2C level shifters HV.
So do I use an external 5v supply? Im a bit stumped with how to wire it. Trying to follow this : https://littlebirdelectronics.com.au/guides/196/using-a-logic-level-shifter-with-raspberry-pi
Yes, you need a separate 5V (Arduino in your URL) that drives the HV side. In your case a separate PSU (Power Supply Unit) 5V will drive the relay module and the 5V side of the level shifters HV.
Thank you for the advice. Can I get away with using a USB board and take 5v from there?
It depends, if it uses the same USB power as the Pi = No
Ah ok. I was planning on taking the 5v from the Pi's USB but ill just use an external 5v battery pack.
Or you can just solder a wire to 5V rail on the down side of the gpio.
Not mine but found this online
yeah just put some hot glue later so it doesn't short
i Wouldn't do it that way!
why not 😄
ah relay board with its own controller, yep not there yet for me
just get a psu for the relay board tbh
Well there is not reason for that but if you want it that way.
The rpi wound have no problem with 235mA.
i mean is there some pins that can extend under the board ?
also like that you put more stress in the 5v rail since already the lcd gets power from there (imo)
yeah not much
like i am saying 235mA is nothing
<@570603770195738645> <@190422021757206530> I had a USB power bank near me so I've tried using that before drilling holes in my case. I joined the GND from the Battery to both the Pi and Relay GND and only the 5v from the Battery to the relay. SDA and SCL are connected normally. I can see the relay in the Pi CLI now but still can't trigger the relay. It could be that I don't have the right relay number but I have no idea how to find that info out automatically without going through each relay 1 by 1.
you are not using any level shifter
the scl and sda needs to be 5v for the relay module
not 3.3v that is coming from the rpi
idk relays like those i activate them with like 12v
maybe less even thats why i use them
Those ones are bus operated yes
But ig the 5v isn't just to activate the relay, maybe to power the controller too
If the coil is sensitive it can operate even from the Pi's 5v rail then
i have no idea why did he use the powerbank
the whole relay module has max current of 235mA and that is almost nothing for the rpi
so there woulnt be a problem using the rpi to power the relay module
Forgot the specs of original pi4 psu even
its 5v 3a
Use some 12v psu, like 12v 2a and use stepdown to USB for 5v pi, plus you get 5v for whatever else you want
why?
I have similar one
Just incase something is power hungry
Main supply and plenty room to work with
Can pull more wattage than pi4 psu
why?
just use the normal 5v 3a original usb-c power supply it is enought
I mean just incase he wanna add more stuff later or idk rly xd
well if than why not but its not needed yet so why waste money
It will cost like 10$ max
the level shifter and relay module should use the same 5v rail but it would propably not make any diference because those are just data pins but still it would be better if they would use the same 5v rail
Now make music with the relays
Like click clack in rythm
Nearly. I can talk to them but they not activating 🙄
then use the coreect library
Was about to say see the voltage output but it's bus operated 🗿
I bloody did it!!!! I found it easier to read the memory address of the chip and use the command i2cset with SBUS and memory address.
Thanks for the help lads!!
NP
close this thread then
Don't close it I wanna see progress
Im working on getting the relay buttons on the touchscreen but thats a big bridge to cross. Mind you I have no experience in ANY on this stuff.
Sounds like Minecraft redstone
I should have it all finished by tonight. Ill make a video when Im done.
Oh you making 3d printer
I have friend that has some 3d printer that bed heat just goes to max like controller gone
Yeah. It's all finished now. Working perfectly
so you got 3d printer and mod some features on it ez
wait...
No. Pixel 7 Pro. It seems to be pretty decent.
:(((( had hopes someone could help with mine g
saw camera and curves thought was
Whats wrong with yours?
cant connect to certain wifi's
like my home miktorik 5ghz specifically and some public ones
Try this.
Why are ther I2C Pins on your Relay?
Oh okay
They are fun to play around with. Getting another one for my projects.