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

[marekd1]

Hi, thanks for the tip. However in the Adafruit tutorial (PCA chaining) there is no mention of this and they say up to 62 can be chained !
Also many of us are running reef pi with PCA and pH boards working nicely together. So i would assume that it is just a precautionary act rather than necessary.

I am pretty sure you will have to remove them as both I2C lines need pull up resistors unless they use some exuberantly large value for the resistors. You have two options; source the schematic of the device or measure the resistance between SCL and VCC then SDA and VCC before you plug it in to the i2C bus and after you plug it into the i2C bus. (Without applying power to the circuit) If the resistance value is half after you plugged it in then you will eventually have a problem. Anything less than 1K Ohm resistance on pull up will create an issue.

found the schematic in the document they publish but can't read the value (see the red box). 66 devices I don't think so...

Just to picture the impact, if you have 10 boards and each board has 1k pull up resistors your final resistance on the i2C bus will be 100 Ohms. Not sure if you will be able to pull the line low with that level of resistance not to mention the amount of current you will be draining on the lines. If the processor gets hot you will know why

Hope this paints a better picture

 

[Dave's Reef]

Hi everyone so I have a question I have been trying to figure this out for a few day and have skimmed over like 100 pages of this thread and cant seem to find any instructions on the hs300 and how to make it communicate with reef-pi I found the IP address of the power strip and see where to add it in reef-pi but I keep getting an error that it can't be found.. please help its driving me crazy. I'm sure I'm missing something stupid. Can you please point me in the direction of some type of instruction on how to make this work?

Thank you

 

[Urtoo]

The IP needs :9999 at the end

example, mine says 192.168.10.15:9999

 

[Dave's Reef]

The IP needs :9999 at the end

example, mine says 192.168.10.15:9999

Thank you I'm and idiot. I remember seeing that but not realizing that I had to add that I though it was just signifying where you put your IP thank you it works perfectly now

 

[Matevz Savarin]

Hi all about pumps.. I cant adjust speed, ok I can from 95 to 100% but less then that I just get noise out of mosfets. Can I do something about that. If not ok.. just asking.
For others I am using led driver as output for control 4,5,6 pins on mikes hat, all works as it should exept that speed thing..

 

[BenB]

Hi all about pumps.. I cant adjust speed, ok I can from 95 to 100% but less then that I just get noise out of mosfets. Can I do something about that. If not ok.. just asking.
For others I am using led driver as output for control 4,5,6 pins on mikes hat, all works as it should exept that speed thing..

There is an option to change the PCA9685 frequency. You will have to change the frequency to the optimal one.
You can start at 100Hz and make steps of about 200Hz, later you can fine-tune if needed.
Some PCA9685 have max 1500Hz and other max 1000Hz.

 

[Matevz Savarin]

BenB thank you! I will do this. I have another glich, my dashboard wont recognize pumps I get http error item doesnt exist. They are all turned on and working with calibrate buttons. I have then configured under jacks and under pumps. Am I missing something?

 

[Matevz Savarin]

Nevermind was a bug in chrome.. in safari it works ok. Next on my list is led controller for 3x marsaqua but for seperate light channels.(I hope) Again thank you Ranjib and Mike for all your work hire. Greetings from Slovenia!

 

[robsworld78]

Just a note to be aware of: each pca9685 has pull-up resistors for the SCA and SDA lines. If you are planning to add more than one board you should remove them on the others as they will be all in parallel drastically reducing the overall resistance. As a result I2C communication will be failing or be inconsistent.

The PCA9685 operates with a supply voltage range of 2.3 V to 5.5 V and the inputs and outputs are 5.5 V tolerant.

And you can connect more than one like this:

And give it a proper address. https://learn.adafruit.com/16-channel-pwm-servo-driver/chaining-drivers

If the second pca9685 is in another box that is further away than 1 meter best is to use a shielded cable.

If you have multiple I2C devices connected or want to extend further look at the PCA9507 these work well. Easy to connect and I can confirm 25ft of USB cable is no issue although probably still not a good idea. Still need to remove additional pullups for extra devices.

 

[brandonq81]

Can anyone help me get a Ph Probe setup in Reef-Pi? I am just starting out, and I am stuck. I am using the Atlas Scientific EZO-pH board. I have a Raspberry Pi 3 Model B setup with Reef-Pi version 3.2 for Pi 3. I've enabled I2C on the Pi. I can read from the probe with a basic python program, and I have setup the driver, analog connection and probe. I can calibrate the probe, but when I try to enable the probe I get an error:

When I try to add the Ph to the Dashboard:

I get the same error and don't see any output:

 

[marekd1]

If you have multiple I2C devices connected or want to extend further look at the PCA9507 these work well. Easy to connect and I can confirm 25ft of USB cable is no issue although probably still not a good idea. Still need to remove additional pullups for extra devices.

Nice find. Now this becomes very interesting, remote I2C devices over 2 wire bus + ground. Cat5 should help with capacitance. Looks like spec is quite large. See below.

Check this out... https://www.ebay.com/itm/Differenti...638844&hash=item1a3653139a:g:XrwAAOSw~RVaGkNP

look at the signal waveform over 300m

 

[Ranjib]

Can anyone help me get a Ph Probe setup in Reef-Pi? I am just starting out, and I am stuck. I am using the Atlas Scientific EZO-pH board. I have a Raspberry Pi 3 Model B setup with Reef-Pi version 3.2 for Pi 3. I've enabled I2C on the Pi. I can read from the probe with a basic python program, and I have setup the driver, analog connection and probe. I can calibrate the probe, but when I try to enable the probe I get an error:

When I try to add the Ph to the Dashboard:

I get the same error and don't see any output:

The stats related errors are benign and will go away after some time. Did you setup the ezo circuit to be used as i2c from uart? You have to do that using their python library.

 

[Crustoceous]

I don't know if this has been covered, but I can't find it if it has been. I'm trying to set up a new reef-pi and Inside the Connectors screen there are pins that do not exist according to the interface. For one, I can't assign any analog pins, and pin 2 I get an error saying "Error: inlet test did not get associated with a driver pin: no valid input pin 0: pin 0 unknown". Am I doing something wrong? Other pins I can add, but it seems pin 2 and any analog inputs that I want to assign, I can't because there are none available.

 

[robsworld78]

Check this out... https://www.ebay.com/itm/Differenti...638844&hash=item1a3653139a:g:XrwAAOSw~RVaGkNP

look at the signal waveform over 300m

You win lol. I haven't seen the PCA9600, that's some range. It says it's the high speed version of P82B96 which is a commonly used. I know the PCA9507 isn't the best but very easy to drop inline and you only need one. Differential is definitely better, it splits the signal on two lines which really helps with noisy environments and you can increase the voltage which helps a lot, only downside is you need one on both ends and more conductors.

 

[marekd1]

You win lol. I haven't seen the PCA9600, that's some range. It says it's the high speed version of P82B96 which is a commonly used. I know the PCA9507 isn't the best but very easy to drop inline and you only need one. Differential is definitely better, it splits the signal on two lines which really helps with noisy environments and you can increase the voltage which helps a lot, only downside is you need one on both ends and more conductors.

The PCA9507 is plenty for reef-pi application. I doubt anyone would need 300 meters distance. This opens bunch of new doors for distributed control out of central hub. Very very cool!!! I could have my monitoring probes talk over I2C without probe coax extensions.

 

[marekd1]

The PCA9507 is plenty for reef-pi application. I doubt anyone would need 300 meters distance. This opens bunch of new doors for distributed control out of central hub. Very very cool!!! I could have my monitoring probes talk over I2C without probe coax extensions. Now if we could get the I2C inputs support in reef-pi soon, then this will be complete game changer for remote sensing. Ranjib pressure is on Just kidding. When ever you are ready

 

[robsworld78]

The PCA9507 is plenty for reef-pi application. I doubt anyone would need 300 meters distance. This opens bunch of new doors for distributed control out of central hub. Very very cool!!! I could have my monitoring probes talk over I2C without probe coax extensions.

The system would be more reliable with coax extensions vs I2C runs. I2C was never designed to leave the circuit board as the protocol has no error proofing built in and noise is it's worse enemy but yeah using these buffers go a long way.

 

[rackley]

Spent the last couple of weeks sourcing and building my reef-pi. Very excited to have it all up and running. Question though: I have the optical sensor for ATO and have a float installed just above the optical level as a back up. What's the recommended way of configuring the optical as primary input control for ATO, while using the float as an override to shut off the ATO? Can that be set up with the macro functionality?

 

[Bigtrout]

Spent the last couple of weeks sourcing and building my reef-pi. Very excited to have it all up and running. Question though: I have the optical sensor for ATO and have a float installed just above the optical level as a back up. What's the recommended way of configuring the optical as primary input control for ATO, while using the float as an override to shut off the ATO? Can that be set up with the macro functionality?

Nice looking install!!!

I would not try to use reef pi macro as your failsafe. I would do that in wiring. How do you have the optical wired?

 

[lilgrounchuck]

Can anyone help me get a Ph Probe setup in Reef-Pi? I am just starting out, and I am stuck. I am using the Atlas Scientific EZO-pH board. I have a Raspberry Pi 3 Model B setup with Reef-Pi version 3.2 for Pi 3. I've enabled I2C on the Pi. I can read from the probe with a basic python program, and I have setup the driver, analog connection and probe. I can calibrate the probe, but when I try to enable the probe I get an error:

When I try to add the Ph to the Dashboard:

I get the same error and don't see any output:

It doesn’t have any data yet. All of my sensors kicked that error when I first enabled them. Once it’s enabled an starts recording data it should go away.