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

[Brad Cox]

On the ato setting. It monitors the sensor every so many seconds.

How long does it run the pump for when it sees no water? Until it detects water again?

 

[Ryan115]

Bummer. I'll bring back the high state config. Meanwhile, you can still use the equipments tab right?Its just the buttons means opposite , when you click off, it should turn on equipment and when you click on, it should turn off. Am I right on this?

I have been wondering if it would be possible to have each channel for the outlet control configurable as to which way they switch.
The relay board that I am using (likely what most end up with) has both NO or NC options for each connection. My plan was to have each set up accordingly to which way it is typically running (i.e. return pump NC, skimmer NC, heater NO, etc...). That way I am not having to nearly always hold certain pins high (and use the extra power from the pi) if it is not necessary.
Is this config that you are looking at bringing back going to give this option?

 

[Ryan115]

Can you try this out: http://www.instructables.com/id/Analog-Output-Convert-PWM-to-Voltage/
This will solve the DAC issue without any code changes, and this should be lot cheaper

We will still need to boost it up to 10v to get full range, but should be a viable test as it.
Not sure if it would be cleaner to convert to 10V pwm then run through the LP filter, or filter first.
I don't have a light to test this on, nor quick access to a scope right now. My DMM can measure it out upto ~1kHz. Do you know at what freq. the pwm is running?
Also, I can try to mock up on Tinkercad ciruits (I guess autodesk ported their circuit design stuff over there) and test it out.
They dont have a pi built into it, but principle should be the same with an Uno.

 

[Brad Cox]

We will still need to boost it up to 10v to get full range, but should be a viable test as it.
Not sure if it would be cleaner to convert to 10V pwm then run through the LP filter, or filter first.
I don't have a light to test this on, nor quick access to a scope right now.
I can try to mock up on Tinkercad ciruits (I guess autodesk ported their circuit design stuff over there) and test it out.
They dont have a pi built into it, but principle should be the same with an Uno.

I already built the 0-10v digital circuit so i csn use that if the filter works.

 

[Ranjib]

Heres the installed product!

This is sweeeeeet . :-O)

 

[Ranjib]

We will still need to boost it up to 10v to get full range, but should be a viable test as it.
Not sure if it would be cleaner to convert to 10V pwm then run through the LP filter, or filter first.
I don't have a light to test this on, nor quick access to a scope right now. My DMM can measure it out upto ~1kHz. Do you know at what freq. the pwm is running?
Also, I can try to mock up on Tinkercad ciruits (I guess autodesk ported their circuit design stuff over there) and test it out.
They dont have a pi built into it, but principle should be the same with an Uno.

10v boost is fairly simple, using a resistor and any common npn transistor . i have shared the details earlier here, so thats solved. Lets see how this low pass filter circuit work...

 

[Ranjib]

On the ato setting. It monitors the sensor every so many seconds.

How long does it run the pump for when it sees no water? Until it detects water again?

Yup. But I think thats not very safe. I am planning to introduce a cut off time.. which will stop any accidental over water addition in case the sensor does not trip...

 

[Ranjib]

I have been wondering if it would be possible to have each channel for the outlet control configurable as to which way they switch.
The relay board that I am using (likely what most end up with) has both NO or NC options for each connection. My plan was to have each set up accordingly to which way it is typically running (i.e. return pump NC, skimmer NC, heater NO, etc...). That way I am not having to nearly always hold certain pins high (and use the extra power from the pi) if it is not necessary.
Is this config that you are looking at bringing back going to give this option?

Yeah. Its possible to do this in software, nothing stopping us. Something to note that this can be done in just using circuits as well.. My first thought was to make it as simple as possible from reliability perspective. In this case keeping a pin always high is kinda more work. May be we can simply pull it up..

 

[Brad Cox]

We

Yup. But I think thats not very safe. I am planning to introduce a cut off time.. which will stop any accidental over water addition in case the sensor does not trip...

well im using a aqualifter pump so its very slow. And my sump will hold what my ato stores so ill test it out for awhile

 

[Ranjib]

We will still need to boost it up to 10v to get full range, but should be a viable test as it.
Not sure if it would be cleaner to convert to 10V pwm then run through the LP filter, or filter first.
I don't have a light to test this on, nor quick access to a scope right now. My DMM can measure it out upto ~1kHz. Do you know at what freq. the pwm is running?
Also, I can try to mock up on Tinkercad ciruits (I guess autodesk ported their circuit design stuff over there) and test it out.
They dont have a pi built into it, but principle should be the same with an Uno.

PWM is done by pca9685 IC, the datasheet says it can support anywhere between 24KHz to 1.5KHz. More: https://cdn-shop.adafruit.com/datasheets/PCA9685.pdf

 

[Ryan115]

Yeah. Its possible to do this in software, nothing stopping us. Something to note that this can be done in just using circuits as well.. My first thought was to make it as simple as possible from reliability perspective. In this case keeping a pin always high is kinda more work. May be we can simply pull it up..

I wasnt thinking about having a pin drawn high (actually the opposite). My preference is to only have a pin pulled high when you actually have a reason to switch the relay, like if you want to turn off the main return, which would be on a NC relay. What I wasnt sure about was how the logic is set up for the outlet control. When the pi is turning an outlet "On" of "Off" which way is the pin going? Is that configurable?

PWM is done by pca9685 IC, the datasheet says it can support anywhere between 24KHz to 1.5KHz. More: https://cdn-shop.adafruit.com/datasheets/PCA9685.pdf

Oh yeah, I forgot we already had that conversation. Too much time with Arduino is mixing me up with pi. Should still work in simulator though, if their code compiler was working...

 

[Brad Cox]

What temp probe are yall using? Is it rusting?

 

[Ranjib]

I wasnt thinking about having a pin drawn high (actually the opposite). My preference is to only have a pin pulled high when you actually have a reason to switch the relay, like if you want to turn off the main return, which would be on a NC relay. What I wasnt sure about was how the logic is set up for the outlet control. When the pi is turning an outlet "On" of "Off" which way is the pin going? Is that configurable?


Oh yeah, I forgot we already had that conversation. Too much time with Arduino is mixing me up with pi. Should still work in simulator though, if their code compiler was working...

Currently its not configurable, it used to be a global config , in the early days of reef-pi.

 

[Shigshwa]

Not yet. The code for ph monitoring is in prototype phase, (developed by a local reefer). I plan to integrate it after 1.0 release (unless someone else chime in). But it is definitely something I would like to be in reef-pi

I see. What hardware might be needed for the pH probe, aside from the probe itself?

 

[Ranjib]

I see. What hardware might be needed for the pH probe, aside from the probe itself?

One of the ezo board that lets you read the probes using i2c, wired using a bnc connector, he is using tentacle board . I think its too much, i really dont see the need for 3 or four probes right now. They are also relatively expensive (at least the good ones), which is why I decided to do it part of 2.0.
https://www.atlas-scientific.com/product_pages/components/tentacle-t3.html
https://www.atlas-scientific.com/product_pages/circuits/ezo_ph.html

 

[Shigshwa]

One of the ezo board that lets you read the probes using i2c, wired using a bnc connector, he is using tentacle board . I think its too much, i really dont see the need for 3 or four probes right now. They are also relatively expensive (at least the good ones), which is why I decided to do it part of 2.0.
https://www.atlas-scientific.com/product_pages/components/tentacle-t3.html
https://www.atlas-scientific.com/product_pages/circuits/ezo_ph.html

I have been looking into cheaper alternatives. What happened with the plan to utilize chips like the MCP3008? Then, you could buy a Chinese sensor module like the one below and use it with that, right?

https://www.aliexpress.com/item/Liq...e0-40c9-92ee-a340cbc2acc4&transAbTest=ae803_1

 

[Ranjib]

I have been looking into cheaper alternatives. What happened with the plan to utilize chips like the MCP3008? Then, you could buy a Chinese sensor module like the one below and use it with that, right?

https://www.aliexpress.com/item/Liq...e0-40c9-92ee-a340cbc2acc4&transAbTest=ae803_1

It will work, but the raw sensor values are unlikely to be different, i.e you have to map them from one scale to another scale. Depending upon the probe, you may need specific resistor/capacitor circuit as well. I tried this route with temperature sensor first (using mcp3008 and hooked a cheap digital thermometer probe) .. before landing to ds18b20. I'll evaluate the ph probe electronics as and when I cross that bridge , if you are up for it, test it out. But don't be discouraged if it does not work out as you expect.

 

[Ranjib]

What temp probe are yall using? Is it rusting?

I am using the one with black coating. It has not rusted yet. Sparkfun , and canakit has those.. https://www.amazon.com/dp/B007R9UU5C/

 

[Brad Cox]

I am using the one with black coating. It has not rusted yet. Sparkfun , and canakit has those.. https://www.amazon.com/dp/B007R9UU5C/

Thanks! Ordered!

 

[njtiger aquariums]

I am using the one with black coating. It has not rusted yet. Sparkfun , and canakit has those.. https://www.amazon.com/dp/B007R9UU5C/

This is a nice unit. I have one with the metal tips which has rusted but still works just fine. I got a bag of 5 for like $10 and so far in two+ years I only had to swap one out due to it stopped working. Now that is with moving and having it sit on the self for like a month before going back into a tank. The rust doesn't affect the reading (I test monthly to make sure my reads are still good)