Questions on wiring

[DrewBR]

Hey everyone,

I'm building my own reef pi. I'm a realtive begginer with the Raspberry Pi, I have octoprint running for my 3D printer and I figured might as well have something running my reef tank; Unfortunately I don't have access to a lot of the parts in the guide so some adaptation is in order. No protohat to be found, so a regular protoboard and a ribbon conector with a little prototyping plate built for the Pi will be the replacement. For the power module I bought a 16 channel relay but I'm having some trouble coming out with an adequate adaptation for the circuit. Here is what I tought so far.

Since I have more outlets than the original Pi build, I'll replace the DB9 conector (9 connectors) for either an HDMI (19 connectors) or USB-C. I could use 2 DB9s but I would rather avoid having too many cables. Is this a good enough workaround?

As far as I menaged to understand I still need a 12V pin to power the relay and then 5V and ground, as well as the pins to actually control the relay. So at least 19 pins for the entire thing?

 

[robsworld78]

Hey everyone,

I'm building my own reef pi. I'm a realtive begginer with the Raspberry Pi, I have octoprint running for my 3D printer and I figured might as well have something running my reef tank; Unfortunately I don't have access to a lot of the parts in the guide so some adaptation is in order. No protohat to be found, so a regular protoboard and a ribbon conector with a little prototyping plate built for the Pi will be the replacement. For the power module I bought a 16 channel relay but I'm having some trouble coming out with an adequate adaptation for the circuit. Here is what I tought so far.

Since I have more outlets than the original Pi build, I'll replace the DB9 conector (9 connectors) for either an HDMI (19 connectors) or USB-C. I could use 2 DB9s but I would rather avoid having too many cables. Is this a good enough workaround?

As far as I menaged to understand I still need a 12V pin to power the relay and then 5V and ground, as well as the pins to actually control the relay. So at least 19 pins for the entire thing?

Looks like your relay module is 5v so you don't need 12v, just 5v, Ground and 16 signals. Here's a little guide showing how it connects. You can connect the signals directly to pi GPIO's of your choice. Don't power up the relay module using 5v from the Pi though, that would be pushing the limits of the Pi. Do connect a Ground wire from the Pi to the relay module though.

Guide for Relay Module with Arduino | Random Nerd Tutorials

This post shows how to use a relay module with an Arduino board. A relay is an electrically operated switch that you can use to control mains voltage appliances

randomnerdtutorials.com

I tried using an HDMI cable in the past as it has lots of conductors but it was difficult as some wires are very thin, just a couple strains. Might be easier to stick with 2 DB9's.

Have fun!

 

[DrewBR]

Looks like your relay module is 5v so you don't need 12v, just 5v, Ground and 16 signals. Here's a little guide showing how it connects. You can connect the signals directly to pi GPIO's of your choice. Don't power up the relay module using 5v from the Pi though, that would be pushing the limits of the Pi. Do connect a Ground wire from the Pi to the relay module though.

Guide for Relay Module with Arduino | Random Nerd Tutorials

This post shows how to use a relay module with an Arduino board. A relay is an electrically operated switch that you can use to control mains voltage appliances

randomnerdtutorials.com

I tried using an HDMI cable in the past as it has lots of conductors but it was difficult as some wires are very thin, just a couple strains. Might be easier to stick with 2 DB9's.

Have fun!

I thought I wouldn't need the 12V power at first there is a 12V indicator on the packaging and in the store's website the description says it requires a 12V power supply to work and the 5V supply to control the outlets.

It's a bit of a daunting project to be honest but I'll keep looking for alternatives.

 

[attiland]

I thought I wouldn't need the 12V power at first there is a 12V indicator on the packaging and in the store's website the description says it requires a 12V power supply to work and the 5V supply to control the outlets.

It's a bit of a daunting project to be honest but I'll keep looking for alternatives.

So how many input you have there?

 

[Ranjib]

try running the relay with 5v first, i think it will work. as rob mentioned, just make sure the power is not taken from pi. I have not tried yet, but I will consider usb C for both power and data, if any new scratch builds. There are off the shelf usb c to 12v or 5v PD breakout boards that can do the power part (and you can use fancy apple adapters). There are also normal usb c breakout boards that will provide 20+ pins (iirc)

 

[robsworld78]

I thought I wouldn't need the 12V power at first there is a 12V indicator on the packaging and in the store's website the description says it requires a 12V power supply to work and the 5V supply to control the outlets.

It's a bit of a daunting project to be honest but I'll keep looking for alternatives.

Lots of those modules are 12v but as those relays are 5v you shouldn't need it. I don't see a header for it either, just two marked 5v. If you need any help let us know.

 

[DrewBR]

Thanks for all the help. I have some parts coming in next week. I'll try the 5V first and check if it works and then I'll let you guys know.

 

[DrewBR]

So how many input you have there?

There are 18 connectors 2 for 5 V, 2 for ground and 16 for control. Plus another 2 for power (12V) and ground.

 

[attiland]

There are 18 connectors 2 for 5 V, 2 for ground and 16 for control. Plus another 2 for power (12V) and ground.

Based on this and the pic you cans drive it with 5 or 12 v too.

 

[robsworld78]

There are 18 connectors 2 for 5 V, 2 for ground and 16 for control. Plus another 2 for power (12V) and ground.

Where is the +12v pin? I see an extra for VCC. Do you have a link for the board?

 

[DrewBR]

Where is the +12v pin? I see an extra for VCC. Do you have a link for the board?

The +12V pin is supposed to be the extra one for VCC. I do have a link but it's in portuguese not sure how much help it will be for you guys.

Módulo Relé 16 Canais 12V - RoboCore

Módulo com 16 relés com acionamento independente através de pinos lógicos. Alimente o módulo através dos pinos GND e VCC em 12 V e faça o chaveamento do nível

www.robocore.net

 

[attiland]

The +12V pin is supposed to be the extra one for VCC. I do have a link but it's in portuguese not sure how much help it will be for you guys.

Módulo Relé 16 Canais 12V - RoboCore

Módulo com 16 relés com acionamento independente através de pinos lógicos. Alimente o módulo através dos pinos GND e VCC em 12 V e faça o chaveamento do nível

www.robocore.net

I think best to ask them. The picture say 5 v is the power required

 

[DrewBR]

I think best to ask them. The picture say 5 v is the power required.

I did ask them but no answer yet. The description reads something like this:

Power the relay with 12V through VCC and GND pins, then do the wired logic connection for each relay pin.

 

[robsworld78]

I did ask them but no answer yet. The description reads something like this:

Power the relay with 12V through VCC and GND pins, then do the wired logic connection for each relay pin.

The relays are only 5v so I think you want 5v. If you have continuity meter put one probe on VCC and go though the pins on a relay, if you get continuity to a pin use 5v. Like you said try 5v first.

 

[DrewBR]

The relays are only 5v so I think you want 5v. If you have continuity meter put one probe on VCC and go though the pins on a relay, if you get continuity to a pin use 5v. Like you said try 5v first.

I've ordered a 5V font and most parts for the first 3 reef-pi modules. There is a local store that sells almost everything else I'll need to adapt accordingly . Also I'll probably try wiring a USB-C breakout board the power module.

I'm no pro but I'll make some diagrams as soon as I get the parts.

 

[DrewBR]

The relays are only 5v so I think you want 5v. If you have continuity meter put one probe on VCC and go though the pins on a relay, if you get continuity to a pin use 5v. Like you said try 5v first.

A little update.

No continuity between the 5V pins and the other pins. There is continuity between the VCC(12V) and the 5V pins.

Also I got in contact with the store that sold me the relay, and they said to power it with 12V and wire like any other realy after that. They did not specify the amperage for the 12V power suplly however.

I did buy the LM2596 step down. So now I think the only thing I'm missing is the 12V power supply. How many A should it be?

 

[DrewBR]

A little update.

No continuity between the 5V pins and the other pins. There is continuity between the VCC(12V) and the 5V pins.

Also I got in contact with the store that sold me the relay, and they said to power it with 12V and wire like any other realy after that. They did not specify the amperage for the 12V power suplly however.

I did buy the LM2596 step down. So now I think the only thing I'm missing is the 12V power supply. How many A should it be?

Another Update.

I got a video showing the exact relay module I have. This board does need a 12V power supply since the 5V is not enough to run all the relays. I'm missing the font to make it work and I'll try getting it before the weekend to do some test runs.

 

[robsworld78]

Another Update.

I got a video showing the exact relay module I have. This board does need a 12V power supply since the 5V is not enough to run all the relays. I'm missing the font to make it work and I'll try getting it before the weekend to do some test runs.

Something doesn't smell right. If the VCC and +5v pins have continuity then VCC isn't +12v. I'm pretty sure you only want +5v. The relays are 5v, not good if you put 12v to them. If the 5v supply isn't enough power it's due to lack of current available. Each relay draws 60 - 80 mA so lets say 100mA x 16 relays = 1.6 amps required to activate all relays at same time. If you get a 2-3 amp 5v power supply you should be set.

 

[robsworld78]

I did buy the LM2596 step down. So now I think the only thing I'm missing is the 12V power supply. How many A should it be?

Not sure why you need a LM2596?

 

[DrewBR]

Not sure why you need a LM2596?

I don't need it in theory. My thought process was since it's a cheap piece I'd buy it in case I needed to fall back to the original guide, powering everything with a 12V power supply.