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

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:
1580975133229.png

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.

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.
 
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.
Thank you so much for bringing that up. This is very useful and I was not aware of it.
 
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Thank you so much for bringing that up. This is very useful and I wan not aware of it.

Every i2C board you buy will have pullups, so if you adding more than one its a good thing to check. Just measure the resistance between SDA and VCC then SCL and VCC before connecting to the bus. It should be the same after you plug it into the bus.


here is a typical case...

1581133391313.png
 
Quick question as I haven't found the answer easy enough. What's the best/easiest process to update to the newest version and keeping your current settings?
 
Quick question as I haven't found the answer easy enough. What's the best/easiest process to update to the newest version and keeping your current settings?

follow this process, just replace the version components...

 
Quick question as I haven't found the answer easy enough. What's the best/easiest process to update to the newest version and keeping your current settings?
Upgrading from 2.x to 3.x will require setting everything up again. The settings are not compatible between the 2 versions.
 
Upgrading from 2.x to 3.x will require setting everything up again. The settings are not compatible between the 2 versions.
Thanks. I'm thinking 3.0 to 3.2. Does the upgrade keep your settings or do i have to backup/replace the db or do i have to write down and redo settings from scratch like 2.x to 3.x ? Just wondering from thoae that have done it.
 
Thanks. I'm thinking 3.0 to 3.2. Does the upgrade keep your settings or do i have to backup/replace the db or do i have to write down and redo settings from scratch like 2.x to 3.x ? Just wondering from thoae that have done it.

3.0 to 3.2 you don't need to reset.
 
Thanks. I'm thinking 3.0 to 3.2. Does the upgrade keep your settings or do i have to backup/replace the db or do i have to write down and redo settings from scratch like 2.x to 3.x ? Just wondering from thoae that have done it.
all settings are retained. upgrade process is the same
 
I'm still working on my stand but getting closer, if the weather would co-operate would allow me to get more done. I know its been discussed a lot but one of the items I am trying to figure out is what is everyone using for ATO with reef-pi. My DT will only be 29G so it will not require a large ATO but would like to figure out what is one of the more reliable ones to look into, e.g., optical vs float etc.

Thanks
 
I'm still working on my stand but getting closer, if the weather would co-operate would allow me to get more done. I know its been discussed a lot but one of the items I am trying to figure out is what is everyone using for ATO with reef-pi. My DT will only be 29G so it will not require a large ATO but would like to figure out what is one of the more reliable ones to look into, e.g., optical vs float etc.

Thanks

I'd probably get a small pump or even a dosing pump. I'm using a tunze osmolator pump on my 120, but that would be overkill for a 29g tank lol. With a 5g jug you'd be set for a while.

On mine I have to refill the 5g bucket every 3 days or so. I need a bigger reservoir.
 
I'm still working on my stand but getting closer, if the weather would co-operate would allow me to get more done. I know its been discussed a lot but one of the items I am trying to figure out is what is everyone using for ATO with reef-pi. My DT will only be 29G so it will not require a large ATO but would like to figure out what is one of the more reliable ones to look into, e.g., optical vs float etc.

Thanks
Optical, mechanical, and capacitive sensors can all be used with reef-pi. I think mechanical float sensor makes the most sense unless there are other restrictions.

Here's how I understand the differences between them.

Optical
+ No moving parts to get jammed by snails or algae
- Water drops can stick to the sensor causing false readings

Capacitive
+ Can be mounted on the outside of the reservoir
- Somewhat difficult to get lined up exactly where you want it since the trigger point is somewhere in the sensor

Mechanical
+ Inexpensive
+ 2 can be wired in series to provide fail safe shut off
+ Easy to identify switching point
- Snails and algae can cause the switch to stick
 
Optical, mechanical, and capacitive sensors can all be used with reef-pi. I think mechanical float sensor makes the most sense unless there are other restrictions.

Here's how I understand the differences between them.

Optical
+ No moving parts to get jammed by snails or algae
- Water drops can stick to the sensor causing false readings

Capacitive
+ Can be mounted on the outside of the reservoir
- Somewhat difficult to get lined up exactly where you want it since the trigger point is somewhere in the sensor

Mechanical
+ Inexpensive
+ 2 can be wired in series to provide fail safe shut off
+ Easy to identify switching point
- Snails and algae can cause the switch to stick


Will have a 20G long sump, maybe go with a mechanical float with an optical backup. So many things that I am working on but trying to collect things to have on hand so when I get to that point I can just continue along. I have one float already will need to figure out what else is needed to make it work. :)
 
Hey Mike I ordered all of your parts to make the reef-pi build easy since I have so many things to work on. One question, for the 29G is deeper than the 20L, looking at the mars aqua lights with your controller, trying to decide if I should go with the 300W vs the 165w light. I know that will be more than needed but I figure I can always dial it down but wanted to get your opinion since I know you are running a bunch of the 165w versions.

Thanks
 
Hey Mike I ordered all of your parts to make the reef-pi build easy since I have so many things to work on. One question, for the 29G is deeper than the 20L, looking at the mars aqua lights with your controller, trying to decide if I should go with the 300W vs the 165w light. I know that will be more than needed but I figure I can always dial it down but wanted to get your opinion since I know you are running a bunch of the 165w versions.

Thanks
I'm not sure how to effectively have the optical as a back up to the mechanical float switch since they operate in fundamentally different ways. Lots of people have done different things though, so I'm sure it's possible.

I have a 165w fixture over a 20 gallon tank. I don't feel like I have any problems with the depth, but I feel like it doesn't have sufficient spread to the sides of the tank. I'm eventually upgrading my 20 and 15 gallon tanks to 29 gallons and I'm not sure if I'm going to change the lights.
 
Quick question as I haven't found the answer easy enough. What's the best/easiest process to update to the newest version and keeping your current settings?
If you are upgrading into major version 1 to 2 or 2 to 3, your data will be lost (actually not lost, but not usable/understandable by newer reef-pi). Within a major version , Minor upgrades should be seamless (1.2->1.3 or 2.1 to 2.4 ) . This is we try to preserve, but occasionally we do end up having bugs in minor version upgrades that may lead to some data inconsistency, generally we path those urgently.

we are relatively new project, and over time (post version 5) I would expect the major version upgrades to be seamless as well
 
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