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

[figaro93]

hi guys I started to build my reef-pi but I immediately ran into a problem I mounted an 8-relay card
I created the sockets taking care that the gpio pins were the correct ones I go into the equipment I create the physical grip and upon activation the input to the raspberry arrives (I see the green light flashing)
but the relays do not start ...
I saw, however, I miss the ULN2803A chip (already purchased waiting for me to arrive) because of this chip I can not activate the relay?
Thank you

 

[b4tn]

hi guys I started to build my reef-pi but I immediately ran into a problem I mounted an 8-relay card
I created the sockets taking care that the gpio pins were the correct ones I go into the equipment I create the physical grip and upon activation the input to the raspberry arrives (I see the green light flashing)
but the relays do not start ...
I saw, however, I miss the ULN2803A chip (already purchased waiting for me to arrive) because of this chip I can not activate the relay?
Thank you

The 2803 reversed the bias of the pi output. For example when you trigger an output on the pi it will go on 3.3v. When you trigger it through the 2803 it goes to ground.

So you need to check your relay module to see if it’s a high, low level trigger, or both depending on a jumper. If it’s a low level trigger relay it will not activate from the pi pin but will work from the 2803. If it’s a high level trigger relay it will work direct off the pi pin but not off the 2803.

 

[figaro93]

How can I check this?

 

[b4tn]

Do you have a link for the relay module you purchased?

 

[dmolavi]

I never looked at these things. In fact I try to avoid pretty much everything thats fancy and based on something thats more original.
My experience has been that we are not limited by CPU/Memory. Yes there are cases where we have hit the ceiling , and may be there are some use of extra CPU/Memory. But 99% of the time we are actually struggling with neat features, reliability, documentation etc. Put other ways, my personal focus has always been to get the story right, i.e. get a functional controller running that can does the daily chores of reef keeping and can be built by most DIY enthuthiast. Sticking to original Raspberry Pi and avoiding most fancy things helped me achieve that, as I ride on the shoulder of those giants. We get to use standard raspberry pi/adafruit community help, and continued software improvements. This does limit us in some way, but I think its worth the compromise. Its ok to not be able to run both webcam and the entire controller in pi zero, as long as it can does the main controller bits, for each of us, easily and forever without hiccups.

In the very beginning when I started reef-pi development, reef-pi was named reefer and I was aiming to make it compatible in all sorts of hardware (Raspberry Pi, Intel Edison, Beaglebone ... etc), I also had all sorts of fancy things (like level sensors , etape). But after doing all of that for good 8 months, I realized that very few of those things actually help me in better reef keeping. In fact it was clear that I can do reef keeping without a controller, but having one that does the monotonous work and adds some extra safety gears is actually worth my time and effort.

Now, all that being said, after reef-pi 3.0 release I think we'll nail down some of the advanced features as well (peristaltic pumps, wavemakers, clustering etc) and I am open for suggestion on moonshot ideas, but I would still emphasize on use case first. i.e. we have to think about what this particular thing gives us, just more of anything is not useful, but if we have a use case (for example, we may decide that we'll do time series analysis on the temperature /ph data and predictively alert folks when equipment or tank act anomolous, instead of fixed threshold based alerting) that actually benefits reef keeping , and the new fancy things is required for that, then I'll definitely consider it

I dont mean to be rude, but I want to keep reef-pi features (software and hardware) coherent, for it to be effective and for me to be able to maintain it easily. Hope you understand

You weren't rude at all. I knew there was a specific use case involved here, just didn't know if the code would be able to run on other architectures. I do agree that it's good to do one thing very well instead of a lot of things "just ok"....

 

[dmolavi]

Also, what's the roadmap for 3.0, featurewise? (I'm an engineer, so I know better than to ask 'when' )

 

[DirtDiggler2823]

Were you able to resolve this? Let me know if you need any help

I did get it sorted out, but when I work up this morning the Reef-Pi was saying my temperature was 262, which I found to be interesting. I sealed the probe in silicone a few days ago, and just submerged it yesterday. It did work properly for several hours, but around midnight, the temp reading skyrocketed to 262 and only dipped to 185 every few hours or so. I might need to get a new temp probe, unless this is something that has happened before and there is a ways to address it.

 

[DirtDiggler2823]

Wasn't there a waterproof temperature probe that was being discussed a couple of weeks ago as an alternative to the stainless one?

 

[figaro93]

Do you have a link for the relay module you purchased?

This relay module

SeeKool relè Relay modulo 5 V con... https://www.amazon.it/dp/B07D8RF6MK?ref=yo_pop_ma_share

 

[dmolavi]

Wasn't there a waterproof temperature probe that was being discussed a couple of weeks ago as an alternative to the stainless one?

you can try the ones from Ranco - they'll shrink wrap them for you: http://www.rancoetc.com/ranco-etc-1309007-044-replacement-sensor

They can be bought from other places besides them (they're out of stock right now).

 

[DirtDiggler2823]

you can try the ones from Ranco - they'll shrink wrap them for you: http://www.rancoetc.com/ranco-etc-1309007-044-replacement-sensor

They can be bought from other places besides them (they're out of stock right now).

That link is giving me a 404. What other places sell the waterproof temp probes. One looked like it was covered in plastic dip already, but since this thread is so large that it's about to become sentient, I just decided to ask.

 

[dmolavi]

Is there a specific interface needed or just a generic one wire probe?

 

[dmolavi]

There is always the Apex probe. More expensive ($30) but waterproof. Snip the connector end and you have access to the wires.

 

[DirtDiggler2823]

Is there a specific interface needed or just a generic one wire probe?

There was a picture of one on here. It was coated in black plastic.

 

[stefanm]

This relay module

SeeKool relè Relay modulo 5 V con... https://www.amazon.it/dp/B07D8RF6MK?ref=yo_pop_ma_share

Check that you actually have a 5 volt version and also worth running it on a separate power supply, I had similar one on running on an Arduino, though it was active low and worked the opposite way around, I don't think you need to tie the ground to the pi if using a separate PSU.

 

[b4tn]

It has to be the ds18b20 to work. This is the one everyone talks about.

https://www.sparkfun.com/products/11050

You could also just buy the sensor itself from any electronics parts place and make your own probe.

 

[bishoptf]

Wasn't there a waterproof temperature probe that was being discussed a couple of weeks ago as an alternative to the stainless one?

If you don't mind me asking whats wrong with the stainless unit? If I were to seal up the stainless i would put heat shrink around it and just a little bit of silicone at the top and nottom and then shrink it, on the bottom whne hot I would pinch it shut, that should do pretty decently.

 

[DirtDiggler2823]

If you don't mind me asking whats wrong with the stainless unit? If I were to seal up the stainless i would put heat shrink around it and just a little bit at the top and nottom and then shrink it, on the bottom whne hot I would pinch it shut, that should do pretty decently.

Mine is showing the temperature as 262 degrees, so even though I sealed it it took a dive.

 

[bishoptf]

Well been a little slow on the updates, I needed to rebuild my bench PC and had to do some major surgery on it, plus it was almost 60Deg yesterday and was really nice to be out. I soldered up everything last night, always takes me much longer to get things soldered but I think the PWM expansion board is ready to go, here are some pics. I started testing my small led and setting the frequency to 300, wow what a strobe effect. Funny but I am actually back to using 100, lol go figure but while ti doesnt seem to cycle, it produces a flicker free light about at the proper voltage.

I haven't tested with the big light yet but will be doing that soon. I did also manage to crash reef-pi a couple of times this morning when playing with the frequency setting and doing reloads a bunch of times. Not sure which logs you store info in, Ranjib if you can tell me where to look I am curious as to what issue it was having.

 

[bishoptf]

Mine is showing the temperature as 262 degrees, so even though I sealed it it took a dive.

Hmm I thought they were already sealed, I bought three of them to use as heater failsafes, if they fail that way then my heaters will get shut off, which at this time of the year is not good. Have other users had issues with the probes?