Atlas Scientific Multi Circuit I2C Carrier Board

[ChrisC]

Hi Rob, I have been looking at the Atlas probes and noticed the multi circuit I2C carrier board. I'm just checking to see if it will work with RT hardware/software. Also what your opinion of using it in a setup?

Thanks
Chris

[Rob F]

Hey Chris, yeah the multi circuit I2C carrier board will work.

Their new Tentacle shield would need a logic level converter as its only 5v compatible.

They also say the PWR-ISO board is needed if you use the conductivity circuit, this isolates it from the other circuits.

https://www.atlas-scientific.com/product...r-iso.html

I'm a planted tank guy with no co2 so none of these are important to me, I did buy the ph stamp and single carrier board just to set it up and it seems to work good. If you want to control relays or water pumps based on water parameters then they would be very useful otherwise its only a value on the screen.

EDIT: actually the multi circuit I2C carrier board won't work with the conductivity circuit, it needs its own carrier board along with the PWR-ISO.

[ChrisC]

Thanks for the quick reply, I'm setting up a reef tank after about 7 years of being out of the hobbie. I'm thinking about using 2 probes mostly as a fail safe control, a ph probe as a backup monitor for a co2 system and a conductivity probe as a backup to shut ATO, AWC off if something goes wrong. Also I sometimes like to see those values on the screen just for my peace of mind. :-)

[Rob F]

Sounds like fun, a lot more gadgets to play with now I suppose. You can also add extra sensors or floats as backups to the ATO, technically 7 in total.

[rott]

Stop the bus I have all them bits and it won't work. the ph stamp works great till you add the conductivity stamp the conductivity goes all over the place and the ph mostly stops working. Unless you want to isolate each chip you are stuck with one chip there is another website that has a isolation board he has a lot of boards EC, Ph isolation but always out of stock but he has the gerber files for d/l with bom fileI have 10 isolation boards but either they don't work or my bad soldering it didn't work
I would be willing to send one or 2 up to Rob with some parts if he has time??

[Rob F]

It doesn't work because as I mentioned you need the PWR-ISO when you add the conductivity circuit, Atlas says that on their website. That isolates it from the other stamps. Its not the controller its the way atlas designed the circuits. Just make sure whatever board you use is 3.3v compatible otherwise it won't work. You can send them rott, I'll solder them up.

[ChrisC]

In the documentation they show how to hook up the conductivity prob on an isolated circuit and the rest of their probes on another circuit. Because I'm not an elictrical guru I will probably buy the isolation circuit from them for $36. I also found a logic level converter that I think will work what do you think?
http://www.ezsbc.com/index.php/products/...uy4cvD3aK0

[Rob F]

I'm sorry, the multi circuit I2C carrier board can't be used with teh conductivity stamp period. Even with the isolation circuit as its a single connection to the board and a trace connects each of them so they're on the same line no matter what.

You need the single carrier board for it along with the isolation circuit. You wouldn't need the logic level converter as the stamps are good for 3.3v.

So you would need 2 - single carrier boards, 1 - PWR-ISO, the circuits and the probes. I hope you haven't ordered it yet...

[ChrisC]

I haven't ordered yet, thanks for clearing that up. It makes sense the conductivity board would need a completely separate carrier board to isolate it.

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It looks like you can put the other 3 ph, orp and dissolved oxygen on the multi board together and it will work. Is that how you see it?

[Rob F]

Yeah it makes sense, and I agree any combination of the others should work on the multi board. The controller is only setup to handle one of each though.

[whitbeox]

Hi there, creator of the Tentacle Shield(s) here.

You probably know it - as soon as you're using the Conductivity sensor in your setup, you'll want to isolate your other sensor circuits. You can leave Temp and Conductivity non-isolated, but you definitely want to isolate pH, ORP and DO. Isolating the Conductivity only will not solve the problem.

The 4-channel version of the Tentacle shield is 5V only because it generates the voltage (5V) for IO (SCL/SDA) on board. So, your micro must be 5V tolerant. Also for the isolated DC/DC circuits to work, they need to be powered by 5V.

The 2-channel version ("Tentacle Mini") however can be used on 3.3V devices. It still needs 5V to power the DC/DC circuits, but you can apply 3.3V on its "IOREF" pin. The IO (SCL/SDA) will be powered by the voltage on IOREF. This will make it work on 3.3V only controllers.

Both Tentacle shields (4- & 2-channel) can be ordered in "Kit" version. It will come without the Arduino pin headers soldered. So you could solder your own custom connector.

Schematics of the 4-channel version:
https://github.com/whitebox-labs/tentacl...ematic.pdf

Schematic of the 2-channel version:
https://github.com/whitebox-labs/tentacl...ematic.pdf

Let me know if this works for you.

Patrick / Whitebox Labs

[rott]

Patrick your tentacle boards are very nice. I see one of the 4 port boards under my xmass tree already.

[fietsenrex]

so patrick let me get this straight.

I can just buy the 2-channel version, install a PH and EC stamp+sensor on them?
and set the circuits to I2C and place the jumpers accordingly and hook them up to the robo-tank and I'm all set?

[rott]

no it will not be that easy

[fietsenrex]

aside from the wiring aspect, why?
it's stated that the 2 and 4 channel boards have full isolation and that you would be able to mix the sensors and keep everything working

[rott]

just guessing there has to be some kinda support in the sketch for there board and still only support for ez chips there boards will support all the atlas chips we use back to version 3x I believe but the software wont

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anywho going to let Patrick and Rob hash it out I have to get back to work

[Rob F]

so patrick let me get this straight.

I can just buy the 2-channel version, install a PH and EC stamp+sensor on them?
and set the circuits to I2C and place the jumpers accordingly and hook them up to the robo-tank and I'm all set?

Hi Fietsenrex, it is that easy. The controller is setup to work with all 4 EZO circuits, just need to connect 4 wires and put circuits in I2C mode.

Hi Patrick, I do have a few customers using your 4 channel shield on the Mega 2560. I know the 4 channel version is only 5v but was told it can be used on 3.3v using a logic level converter on the SCL/SDA lines, is this correct?

[rott]

WOW I was really hoping I was wrong and Fietsenrex was right about the plug and play makes life easier

[whitbeox]

To be honest, I don't know a lot about Robo-Tank and its implementation details. But what I can say is this: Both (2- / 4-channel) Tentacle Shields are mostly a transparent isolation wrapper around the EZO circuits.

The 4-channel version has support for legacy circuits (pre-EZO, not I2C capable) and EZO circuits in UART and I2C modes. Therefore it has jumpers (to connect them to either the i2c bus or the UART line). The 4-channel version also comes with a serial multiplexer on board, so some (max 8) circuits can be connected via one serial port. Some additional pins are used to configure the multiplexer.

Also see https://www.whiteboxes.ch/tentacle/jumper-settings/ and https://www.whiteboxes.ch/tentacle/i2c-or-uart/

The 2-channel version is i2c only. So your circuits must be of the newer "EZO" type circuits. And you have to put them into i2c mode prior to mounting them to the shield. As it is i2c only, there are no jumpers on this shield to configure.

I can just buy the 2-channel version, install a PH and EC stamp+sensor on them?
and set the circuits to I2C and place the jumpers accordingly and hook them up to the robo-tank and I'm all set?

If Robo-Tank uses i2c, yes.

aside from the wiring aspect, why?
it's stated that the 2 and 4 channel boards have full isolation and that you would be able to mix the sensors and keep everything working

Yes - both isolate each channel individually. If your circuits are in i2c mode, the order of placement on the shield does not matter as you'll talk to them using the respective ID.

just guessing there has to be some kinda support in the sketch for there board and still only support for ez chips there boards will support all the atlas chips we use back to version 3x I believe but the software wont

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anywho going to let Patrick and Rob hash it out I have to get back to work

It depends. If Robo-Tank talks to the circuits on the I2C bus, no special code is needed. The shields will just be transparent and not be "seen" by the controller. However, if Robo-Tank uses UART to talk to the circuits (e.g. for backwards-compatibility with pre-EZO circuits), the 2-channel shield can NOT be used (as it's i2c only). The 4-channel board needs some additional pins to configure the UART multiplexer if you're using the circuits in UART mode. Most probably this will need some changes to the code and additional pins from the Robo-Tank.

Hi Patrick, I do have a few customers using your 4 channel shield on the Mega 2560. I know the 4 channel version is only 5v but was told it can be used on 3.3v using a logic level converter on the SCL/SDA lines, is this correct?

I have never tried to use a level shifter - but I see no reason why it should not work. Let me know how it goes once you try it. Anyways, you'll still need to power the shield using 5V.

[Rob F]

The circuits are easy to connect Rott, but only works with new EZO circuits as I'm using I2C. I think you had some older circuits that's why they weren't compatible.

Patrick, the controller is using I2C, currently it can only handle one of each PH, ORP, DO and EC. I'm going to change it so it can use any combination of 8 circuits. I don't have a shield to test, just wondered if you had tried it.