RedBeard's Brew Rig v2.0 build

[andytork]

Wow..that my man is freakin awesome. How well do you find the bubbler system works? I considered it but thought it wasnt worth the trouble.

My bubbler is super accurate, its more down to how round your pots are and how accurate your radius/diameter measurements are.

If you are using MPX5010DP sensors and need a hand, give me a shout. I spent many hours on these.

Here is my workings, don't bother with psi, keep in kpa (as that translates to mm easily) - my pot has a 237 mm radius as seen below. I also use an averaging system to cater for splashing.

formula was
Vout = VS x (0.09 x P + 0.04) ± (Pressure Error x Temp. Factor x 0.09 x VS)
ignoring errors becomes O = 0.2 + 0.45P
or they way we want it p = (O -0.2) / 0.45


Output of below is litres (with decimals)

	val = cMPX5010.GetSensorByName("H")->m_iAvgVal;
	//Serial.print(val,4);
	val = ((5.0/1024.0) * val);		// range is 5v, we have 1024 steps giving 5v
	val = (val -0.2) / 0.45;
	val *= 100;
	val *= (3.1415927 * (237.0*237.0)) /1000000.00;
	cProgram.hlt().SetVolume(val);

 

[cat007]

Hey

Thanks for that.

I have confirmed with the supplier that my DX1 is actually faulty.
Put a constant 3.3V power source onto the analogue input pin and the reading fluctuates around a heck of a lot. Which is why my readings with the bubbler in place jump all over the show.

I'm going to send it back to them for testing and repairs - but will have to wait until I've done all my beers for my wedding in November.

 

[andytork]

Just drop a multimeter on the output pin of the temp sensor (and gnd of course) while you play. You can still leave it hooked to the controller

I use a Arduino mega (self / custom programmed). All mine run at 5v (as can be seen in the code).

Are they non-return valves in before the t-piece for the bubbler ? If not, you need them. Your aquarium pump is almost identical to mine. I just used the el-cheapo non return valves from the fish tank places. The other issue I had was the diameter of the diptubes. I had some thin stainless didn't work, changed for a keg dip tube and it fixed the problems, then went to a diameter in between and its still good.

I just checked the DX1 page, it shows flow control valves not non-return / check valves I had one with a non-return and one without and can confirm you need them

My bubbler rate is every three seconds I bubble at full flow (on pump low setting) for 500ms then take a reading 1 second later. This is essential from my testing to get a stable result

What are your temp sensors ?

 

[cat007]

My post are round - but I've been calibrating it by adding 6L at a time from a known 6L source. But the problem is not my configuration but there's something wrong with my DX1's analogue input circuit.

I'm using DS18B20 temp sensors, daisy chained. They're working perfectly now after adding a 4.7K resistor across the signal and 5V pins on the last sensor has stopped the issue where some of my sensors would read 127C and wouldn't read normally again until I unplugged and plugged it back in again.

The dip tube size is fine - the 3mm I/D has been tested as per this:

https://www.oscsys.com/forums/projects/brewtroller/1002101

Finished insides of the control box - although I've yet to earth the box....oops:

 

[andytork]

Sorry, I meant what's your pressure sensors ?

 

[cat007]

I'm using MPX5010DP

 

[andytork]

The pressure sensors are 5V, is the controller really 3.3v ?

 

[cat007]

No - the controller is 12V.

A computer PSU has 12V, 5V and 3.3V.

I used the 12V bus to power the controller and the 3.3V bus to feed into one of the analogue inputs to give it a constant voltage.

 

[andytork]

I would feed one of the external 5v's or a gnd from the controller back to the a/d input to check min / max. Did you power the temp sensor from the controller or the PC PSU ? You should take power from the controller and use it as a reference into the input to test

The controller will have its own voltage regulators etc to run at 12v , this level of isolation can cause issues with the a/d ref of the controller

 

[cat007]

Hi

By temp sensor, do you mean pressure sensor?

Anyway - putting a steady 3.3V on the analogue inputs should result in a steady reading on the controller. But it doesn't.

I've been talking with one of the designers/builders of the DX1 and they were the ones who gave me the various test scenarios to confirm the fault.