Planning my next steps for hardware. Going to do the sparge water urn next with automatic fill, temperature etc.
Is it possible to use the 1-wire maxim DS2413 as a digital input so I can use it for the level senors?
Does anyone have any experience using the Spark with solenoid valves? What sort of IMF protection did people opt for?
Cheers!
I built a gas burner interface using a solenoid valve to control the gas flow. Be sure to include a flyback diode across your solenoid terminals to deal with voltage spikes when you de-energise the coil.
The pins of the Spark directly cannot supply enough current to drive a solenoid directly.
We’re working on a new board to drive 8 or 16 valves, both solenoid or motor based. First prototype should be finished within a month.
I’ll create an issue for input pins, on the DS2413 and some of the pins of the Spark. It is possible, but I haven’t included all the necessary code yet.
I’m also testing a pressure sensor board that can also sense water level, but that’s probably 6 months at least before it is production ready. So a digital switch with a DS2413 is a good solution until that’s done. Just thought you should know.
pressure sensor I am all for!
PID controlled spunding valve?!?!?!?!?!?
I am all in!
Cool, I was thinking about making a quick PCB with a DS2408 a few power FET’s and a set of ILD213T opto-isolators to drive a set of small solenoids for the input water. Would need some sort of level switch to stop accidents but this could be done in hardware in the first instance.
Well up for this! With 2 good pressure sensors and a venturi you could also measure flow rate of your escaping gas! I’m a sucker for data.
I hope to be able to do this with liquids too.
I’m using 1 bar range sensors for robustness, trying to get long term drift drift free resolution in the microbar range is a challenge 
Well beyond normal temperature compensation or stability duration.
I want to stop with bare onewire devices and use a small micro with modbus instead. More reliable protocol and can handle lost communication or pwm intelligently in the slave.
As driver I’m going to use the vnh7100 for push/pull and current feedback.
You can get differential pressure sensors in the microbar which wouldn’t suffer drift to the same degree.
https://uk.rs-online.com/web/p/pressure-sensors/9227308/
Yes, for air. For liquids I haven’t seen them.
For air this would indeed be a much cheaper solution.
MODBUS has caused me many hours of frustration! Although this is likely a result of needing to use LabView. Would be much more robust.
Doesn’t do well with spurs and reflections tho, will it end up with a requirement for serial wiring (in port and out port on each board)?
A few do exist.
https://uk.rs-online.com/web/p/pressure-sensors/9227409/
The problem is then thinking about cleaning.
I know its not cheap, but
https://www.ifm.com/at/de/product/PI2797
resolution, reliabilty is great. they are even heat resistant - which is imho mandatory for brewing.
One may use two of this to measure the differential pressure.
I’m keen on DS2413 pins as inputs also. I have a door sensor in my fermentation chamber I would like to be able to graph. Would also be good to be able to get it to automatically drive the light in the chamber (with option to manually override).
Would this Board http://denkovi.com/1-wire-eight-channel-relay-board-for-home-automation work with the Brewpi? It can control 8 relays via a DS2408.
That looks good IMHO. Not sure about the effort for Elco to add support for it.
Yes - it really Looks Good to me! Especially because i Need Cooling for 10 tanks 
This is a DIN rail version of it - even more robust : http://denkovi.com/1-wire-eight-channel-relay-module-for-home-automation-with-din-box
What would be the concrete tasks to implement this relay modul to wark with BrewPi? Must there be an adaption of the firmware of the BrewPiSpark?
Yes, a small change to firmware. I’ll try to make time for it soon.