fishinthewall
New member
what the general consensus on relays? are you guys using the in line plugs or wiring relays to outlets?
DIY Aquarium Controller based on Raspberry Pi
- Thread starter metzz71
- Start date
fishinthewall
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nice looks alot neater then what i had in mind
fishinthewall
New member
I've been speaking with the head electrical engineer at my job and I think he is willing to help. He designs and programs ladder logic for Fanuc controllers so this should be pi (hehe) for him. First thing he asked me was if we could default everything in case of failure using normally open/closed circuits. I couldn't think of anything that is critical, any thoughts?
fishinthewall
New member
Ok something like this then. Heater without thermostat, normally closed, backup heater with thermostat set slightly higher, normally open, wave makers and sump return normally open, dosing pumps, ato, water change pumps ,etc normally closed. So system failure leads to backup heater, sump pump and powerheads being left on uncontrolled. Sorry kind of thinking out loud to make sure I get all this 
Pellikan
Member
Djbon; I think fish understands that but merely has his terms reversed. He's talking about what happens in the absence of any input from the controller: ie the Pi is down.
fish: a closed circuit would be equivalent to a light switch in the on position. Open=off It's kinda counterintuitive but that's the way it is.
fish: a closed circuit would be equivalent to a light switch in the on position. Open=off It's kinda counterintuitive but that's the way it is.
djbon
New member
Djbon; I think fish understands that but merely has his terms reversed. He's talking about what happens in the absence of any input from the controller: ie the Pi is down.
fish: a closed circuit would be equivalent to a light switch in the on position. Open=off It's kinda counterintuitive but that's the way it is.
I bet he does. I'm sharing this info with those who wants to build their own controller with extra caution. Heaters with built in controller is okay, but those without will boil your tank if the controller hangs with relays in on position.
fishinthewall
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I'm planning on building one with a temp sensor and coding to to cycle the primary heater. Maybe i shouldn't haven't assumed I couldn't connect a t sensor to the pi
fishinthewall
New member
I need to re read my post to make sure I didn't mix anything up. That is how I meant. So in case the controller goes down primary heater is off secondary is on. So primary is normally open secondary is normally closed
fishinthewall
New member
Ok sorry for the multiple posts.
My thoughts on heaters, have one primary without a thermostat on a normally open circuit. it will cycle as needed from the controller and temp sensor. Then have a backup heater with a thermostat set slightly higher and on a normally closed circuit. in case of power failure the primary heater will be off and the secondary will be on.
Sorry about the confusion
My thoughts on heaters, have one primary without a thermostat on a normally open circuit. it will cycle as needed from the controller and temp sensor. Then have a backup heater with a thermostat set slightly higher and on a normally closed circuit. in case of power failure the primary heater will be off and the secondary will be on.
Sorry about the confusion
djbon
New member
You can have a lot of sensors to Pi or other micro controller for that matter, to fully automate your reef tank. I had a few hang ups on my arduino controller due to logic errors and over temperature on built in regulator. Once done properly, it saves a lot of hassle running a reef tank. I guess that what I pay for DIYing instead of spending money on Apex or similar products
djbon
New member
I agree to this, with extra caution if you're doing your own controller. Myself had a few hiccups where my arduino simply stop executing the codes, with my viewing lights and part of my wavemaker relays are stucked in ON position. If that was on a heater without built-in thermostat, a nice and warm soup should be ready by the time I reached home
.fishinthewall
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xD I figured vigorous testing is gonna be necessary I was thinking about hooking it up to a bunch of lights and moving the temp probe around cold and hot water over a couple of days.
djbon
New member
I'm not familiar with Pi, but both are micro controller which should have the same functionality. Arduino itself comes with quite a number of daughter boards to perform specific functions. If I were you, I won't mixed these two products and save you the hassle of cracking your head on programming.
Arduino comes with different main boards, the differences are the available IO ports for you to choose from. Another thing to consider is the logic programming codes which can be very challenging and time consuming if you start from scratch. These codes are out there if you want to save time producing a workable codes.
