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

[bishoptf]

It’s hard to get solid state relays with high amp rating. The ones I had almost always rated for 2 amp. Yesterday I read through some more documents on this, and the learning was these specs are for max load, for lower loads the lifespan should be much higher , multiple of millions on/off

Just so I make sure are we talking the solid state relays or the ones in the DJ enclosure?

 

[b4tn]

Just so I make sure are we talking the solid state relays or the ones in the DJ enclosure?

He is talking about mechanical Relays I didnt know that a lower load increases lifespan. Thats good to know. A SSR has no mechanical moving parts so it will last dang near forever or at least much longer that a mechanical relay.

 

[bishoptf]

He is talking about mechanical Relays I didnt know that a lower load increases lifespan. Thats good to know. A SSR has no mechanical moving parts so it will last dang near forever or at least much longer that a mechanical relay.

Thanks good to know, even at 100w that's only about 800ma, will still need to think how I want to move forward, as always lots of good information. :)

 

[Ranjib]

He is talking about mechanical Relays I didnt know that a lower load increases lifespan. Thats good to know. A SSR has no mechanical moving parts so it will last dang near forever or at least much longer that a mechanical relay.

Not necessarily. As I was telling you, I spoke to multiple folks in makerfaire (some of them run a 26 foot mechanical giraffe made of iron and steel) and in different forums. Mechanical relays are cheap, available for higher current ratings, and can lust 3-5 years if you use it in its sweet spot. Solid state relays can go bad not due to mechanical wear and tear, but due to heat and other load related issues.

As rfc 1925 , point number 8 states, "It's more complicated than you think" :-)

 

[bishoptf]

Not necessarily. As I was telling you, I spoke to multiple folks in makerfaire (some of them run a 26 foot mechanical giraffe made of iron and steel) and in different forums. Mechanical relays are cheap, available for higher current ratings, and can lust 3-5 years if you use it in its sweet spot. Solid state relays can go bad not due to mechanical wear and tear, but due to heat and other load related issues.

As rfc 1925 , point number 8 states, "It's more complicated than you think" :)

And I thought I was one of the few that got into the weeds with stuff, you start reading rfc's that's getting into it. :)

Some data from my testing so far, 2.5g fluval spec, planted. House is a little warmer today since the sun was out and the ambient is around 70deg. Tank peak started at 78.45 and it took about 30min to drop .5 deg. I have my temp checking every 60s. It may be a little faster if the house was cooler but I think it shows that my on/off cycles shouldn't be to bad. Since this is my shrimp tank I do not need to keep the temp range super tight, 1 to 2 deg should be good enough.

 

[Bigtrout]

There is a reason that even in half million dollar cnc machine that most of the relays are still mechanical. Solid state relays do have their place, but to implement them properly takes good heat sinks and good circuit planning.

 

[bishoptf]

It's tricky on a small tank, I kept 60sec checks since I don't want the heater to stay on longer, for one minute it raises the temp .5deg and then shuts off for almost 20min. I think I can go with this till the summer, I would like a longer swing but since the check controls how long the heater is on I don't want the check to be too long.

I agree that the hysteris would be nice to give a little more leeway, I would be willing to let it cool a little more but restrict the heat. Pretty interesting stuff, the patterns actually looking ok really close to the thermostat in the heater coming on and going off.

 

[Bigtrout]

It's tricky on a small tank, I kept 60sec checks since I don't want the heater to stay on longer, for one minute it raises the temp .5deg and then shuts off for almost 20min. I think I can go with this till the summer, I would like a longer swing but since the check controls how long the heater is on I don't want the check to be too long.

I agree that the hysteris would be nice to give a little more leeway, I would be willing to let it cool a little more but restrict the heat. Pretty interesting stuff, the patterns actually looking ok really close to the thermostat in the heater coming on and going off.

Once every 20 mins is not too much for the relays...and that small of a load means the relay will last awhile.

 

[Stephen Olner]

New to the thread are you using event handlers / listeners within your code

 

[Ranjib]

It's tricky on a small tank, I kept 60sec checks since I don't want the heater to stay on longer, for one minute it raises the temp .5deg and then shuts off for almost 20min. I think I can go with this till the summer, I would like a longer swing but since the check controls how long the heater is on I don't want the check to be too long.

I agree that the hysteris would be nice to give a little more leeway, I would be willing to let it cool a little more but restrict the heat. Pretty interesting stuff, the patterns actually looking ok really close to the thermostat in the heater coming on and going off.

you can use a smaller heater :-)

 

[Ranjib]

New to the thread are you using event handlers / listeners within your code

Thats bit vague question :-). Here are few arbitrary places where such things are used:
The backend code (go) uses http handlers for api. Different parts of the backend uses different mechanism, but most sensor checks are based on timer as of now.
The front end code (react/redux) uses event handlers for DOM/ajax stuff...

 

[daveCB]

Hi All - Been traveling on business and have had no time to play; As a result, my system has been running hands off for a month. Hate to re-hash this, but take a look at the memory over time. This is running on a Pi 3 B and is controlling temperature and device on/off functionality along with reporting.

 

[bishoptf]

Hi All - Been traveling on business and have had no time to play; As a result, my system has been running hands off for a month. Hate to re-hash this, but take a look at the memory over time. This is running on a Pi 3 B and is controlling temperature and device on/off functionality along with reporting.

Which version are you using, they released a newer version that helped with the memory consumption.

 

[daveCB]

Hi Tom;
Version 2.2 is currently running

 

[bishoptf]

Hi Tom;
Version 2.2 is currently running

I think that is the version,since e the update my memory stays pretty flat with the baseline settings, u will try to find the post where @Ranjib called that out.

 

[bishoptf]

Ranjib had this in the instructions:

Thank you for all the help you provide in this project, all of us deeply respect your feedback. For those of you dealing with the memory issue, try configuring the current and historical stats limit to a minimum (say 3 hours of current data, and 7 days of historical, which corresponds to 180 and 168 respectively), if this contains the memory usage, then it means we dont have a memory leak, and the memory usage is legitimate utilization of memory by the stats model. I;ll work on a better scheme to persist stats on disk.. we'll talk about that after the initial finding from tuning stats limits.

I've upped the current data value kept the seven day value.​

This is what I could find deals with current and historical stats, see above. I also saw an old post about the io feed consuming memory. Once I made the changes listed above my memory has been really flat.

 

[daveCB]

I think so. The 2.3 version only updated the lighting frequency issue.

 

[Soulreefer]

Hallow ranjib. Can Reef Pi be installed on Orange Pi?

Thanks

 

[Stephen Olner]

Sorry wasn’t trying to be vague as I don’t know the code or who has written it or what level of programming experience the developer has. I’ll go back to just reading the thread.

 

[bishoptf]

Hallow ranjib. Can Reef Pi be installed on Orange Pi?

Thanks

I'm sure Ranjib will chime in soon but I did a quick look up, it appears that orange pi can run a version of raspbian so it might be possible. I have not seen anyone recently posting about using one and not sure about the pinouts compared to a raspberry pi. Might be one of those try it out and post back on your findings. :)