reef-pi :: An opensource reef tank controller based on Raspberry Pi.

[Ranjib]

Something like this work? https://www.adafruit.com/product/1083 or is there a simpler solution? Pi PWM runs at 3.3vdc, right? Pull the 5v and ground from the Current pump controller, A0 back to center pin, scl and sda from the pi.

I think you mean the opposite: https://www.adafruit.com/product/935
You should try 5V pwm first (use a simple npn transistor to convert 3.3V pwm to 5V pwm) and if that does not work use an RC circuit or a full blown DAC (like the one I linked) to convert the 5v pwm to 0-5V analog.

 

[ScottBrew]

I think you mean the opposite: https://www.adafruit.com/product/935
You should try 5V pwm first (use a simple npn transistor to convert 3.3V pwm to 5V pwm) and if that does not work use an RC circuit or a full blown DAC (like the one I linked) to convert the 5v pwm to 0-5V analog.

Yes, I need a DAC, duh! Thank you... again!

 

[Diamond1]

Does this make sense? I just went ahead and created a new doser diagram in fritzing. I'll use this for the upcoming guide as well

Perfect sense thank you for the updated diagram. Now I just need to combine this with the ph module and I'll be golden.

 

[Ranjib]

Perfect sense thank you for the updated diagram. Now I just need to combine this with the ph module and I'll be golden.

Nice :-)
I am really looking forward to add the support for @Roberto_b 's pH board, it will significantly reduce the cost of building pH monitors, https://www.reef2reef.com/threads/reef-pi-ph-orp-adapter.478158/

 

[Diamond1]

One more thing. What do I need to set the output voltage of the LM2596 at for the dosing pump module?

 

[Ranjib]

One more thing. What do I need to set the output voltage of the LM2596 at for the dosing pump module?

Dosing pump runs on the same voltage as the input voltage (12v), lm2596 is used to convert the 12v input voltage to 5v , for raspberry pi.

 

[Ranjib]

@theatrus just started a separate thread on the pico board: https://www.reef2reef.com/threads/reef-pi-base-boards-pico-etc.499890/
this is going to be awesome :-)

 

[LionHeart2017]

Can I get a little help, my relay has vcc, gnd, com, as it's main connectors, I've plugged the ground into a ground on my pi, the vcc is connected to my 5v psu, which also power the pi, I just don't know what to do with com connection, I tried it in pi 5v and half the little leds on relay lite up so I unplugged, any help?

 

[pickupman66]

Here ya go

This is more complicated that what I did. I just went from the gpio to ground. No resistors, no 5v circuit. Works perfectly for me

 

[LionHeart2017]

Can I get a little help, my relay has vcc, gnd, com, as it's main connectors, I've plugged the ground into a ground on my pi, the vcc is connected to my 5v psu, which also power the pi, I just don't know what to do with com connection, I tried it in pi 5v and half the little leds on relay lite up so I unplugged, any help?

sorted it, vcc to 5v pi, com to 5v psu and ground to pi

 

[LionHeart2017]

So this is my progress on light control for my black boxes, need to add a fan today so I can get some light back on my tank, only been off a day.
Pretty hard trying to modify stuff while you actually need to use it.
Think I'll go with a mesh top to allow the heat to escape but that can wait as it's going on top of my lid out the way.

 

[ScottBrew]

So this is my progress on light control for my black boxes, need to add a fan today so I can get some light back on my tank, only been off a day.
Pretty hard trying to modify stuff while you actually need to use it.
Think I'll go with a mesh top to allow the heat to escape but that can wait as it's going on top of my lid out the way.

That looks awesome, very clean wiring! If you haven't already considered it, you could put a temp sensor in there and thermostatically control the fan if inclined.

 

[Erica-Renee]

So this is my progress on light control for my black boxes, need to add a fan today so I can get some light back on my tank, only been off a day.
Pretty hard trying to modify stuff while you actually need to use it.
Think I'll go with a mesh top to allow the heat to escape but that can wait as it's going on top of my lid out the way.

This is awesome and neatly wired. I do worry about this being in a plastic box and it looks to be mounted on plywood. I worry that if one shorts out and caused a second to do the same it could go very wrong very Fast..
Please consider moving this to a Metal box for safety factors.... Of course its just my opinion Electricity and plastic scares me

 

[Ranjib]

sorted it, vcc to 5v pi, com to 5v psu and ground to pi

I think the relay will work even if you don’t connect anything to com

 

[Ranjib]

This is more complicated that what I did. I just went from the gpio to ground. No resistors, no 5v circuit. Works perfectly for me

Those extra resistors are for safety . I think I have detailed what each of them does to mitigate different risks, but yes the flor switch should work even without them.

 

[Ranjib]

This is awesome and neatly wired. I do worry about this being in a plastic box and it looks to be mounted on plywood. I worry that if one shorts out and caused a second to do the same it could go very wrong very Fast..
Please consider moving this to a Metal box for safety factors.... Of course its just my opinion Electricity and plastic scares me

I am curious , Xbox and even track power supply has enclosed modules with plastic housing. So, is there any specific detail that we should look for ? Like wattage ? And also it must involve the type of circuit as well. Traco psu can be pretty high wattage , and still enclosed in plastic housing . They power rockets .

This is a very important topic as I bet lots of folks will need this info , and I really want to keep safety as one of the most important aspect of this project. If you have any specific guidance here , I’ll gladly put it in the official docs as well. We have a specific section around safety (fire hazard and electrical shocks )

 

[LionHeart2017]

Thanks guys, I do plan to get a two fans one above each set of drivers running on temp control in the near future.
Yes I'm not too impressed with using the plywood base in there, the outer casing is metal as it's a stripped out black box
I actually removed a piece of glass for the hardboard, this is v2 of the housing.
I do still have spare housing to play with so will look at getting a metal base in v3, trouble is then the standoffs, I tried standoffs and just didn't trust them to not short something out on the drivers so ended up with silicone holding the electronics in.

 

[ScottBrew]

Thanks guys, I do plan to get a two fans one above each set of drivers running on temp control in the near future.
Yes I'm not too impressed with using the plywood base in there, the outer casing is metal as it's a stripped out black box
I actually removed a piece of glass for the hardboard, this is v2 of the housing.
I do still have spare housing to play with so will look at getting a metal base in v3, trouble is then the standoffs, I tried standoffs and just didn't trust them to not short something out on the drivers so ended up with silicone holding the electronics in.

What drivers are you using? Most boards with mount holes leave enough room around the holes to be safe and many are grounded through the standoff holes as well. If you are still concerned, how about nylon standoffs and screws?

 

[LionHeart2017]

It's the standard black box drivers, the wiring is in the way on 1 off the corners and lots of small open solder joints underneath at the standoff holes and also the heatsink blocks a hole

 

[Erica-Renee]

I am curious , Xbox and even track power supply has enclosed modules with plastic housing. So, is there any specific detail that we should look for ? Like wattage ? And also it must involve the type of circuit as well. Traco psu can be pretty high wattage , and still enclosed in plastic housing . They power rockets .

This is a very important topic as I bet lots of folks will need this info , and I really want to keep safety as one of the most important aspect of this project. If you have any specific guidance here , I’ll gladly put it in the official docs as well. We have a specific section around safety (fire hazard and electrical shocks )

Most project boxes are not UL Certified for electrical use. I have taken apart items such as x-box and other items and there is Almost always a Metal shield around or under components that have high heat or large capacitors . I am not really the right person to ask what is considered safe. I just know how i do things based on how i have seen Actual Electricians have done so and how things seem to be made.

My concern with is light build is all of those open Power units .I have seen them after a short. If there were one or two and spaced way apart i would probably not have even commented..

Maybe Just reminding people to be aware of safety and Recommend ul approved or Metal box or metal shielding under or behind power components Where high AC Voltage is connected to step down converters or when many Voltage converters are in play together.. I think Lights and Relays are the two things of Concern with our builds . the ADJ Solves one of them for those that can go that rout .For me the Outlets have to be spaced out. I can ask Drew to do a small write up for us about electrical safety that applies to our designs...