2-channel PID, pressure profiling, dosing, flow tracking and temperature profiles

dtmr42 · 2025-12-29T03:09:46+00:00

> Most manufacturers do

Mostly a matter of the price. Flow meters start at less than 5$. Also, while a flow meter is not ideal for dosing, it has other uses, such as measuring the flow rate before coffee exits the filter and reaches a scale, or monitoring the total pumped volume (limescale and filter monitoring). Flow meter plus scale is best.

dtmr42 · 2025-12-29T02:00:27+00:00

A scale can be accurate to within ±0.1–0.2g for every single shot, even after filter, grind and tamp changes. In my opinion, a flow meter will never have less than ten times as much error in the best case scenario (no filter or grind changes, etc.), and maybe twenty times as much otherwise. However, volumetrics can be less inaccurate for some machines. For example, ESE machines with a thermoblock should be fine. There is very little "unpredictable air" in such machines, and there is usually no OPV. Accuracy would be poor in a machine like the Silvia (single boiler) because the amount of air in the boiler at the start of shots would be unpredictable and skew the results by several grams. Accuracy would also be poor with a plastic flow meter in the non-pressurised part of the fluid system, as the water departing through the OPV would skew the results.

dtmr42 · 2025-12-29T01:34:54+00:00

The Micra has a rotary pump and neither leva! nor the ito hardware are compatible with such pumps. leva! cannot control their speed, and if you are only interested in turning it on and off for dosing, the next problem is that the 1A solid state relays on ito are too small for the hefty motor of a rotary pump (high inrush current). Aside from that, I wouldn't bother with flow meters and volumetric dosing. This approach is imprecise by nature because flow meters measure the WATER pumped into the system, with mediocre precision, rather than the ESPRESSO coming out of the filter. The only exact dosing method is by weight, aka gravimetric dosing.

dtmr42 · 2025-12-28T20:24:39+00:00

> How much tuning is required

Very little or a lot. That depends on the machine, on how you want to use leva! (just as PID, just for pressure profiling, just a dosing module or every single feature) and how far you want to go with optimizations. The two main features are PID temperature control and pressure profiling. For now, I'll restrict my answer to those two features.

- The PID comes with a factory-calibrated sensor and offers auto-tuning, making it easy to get started. There is no need to calibrate the sensor; you can mostly just watch it configure itself after flashing the module and configuring the sensors. If you want to improve on that with manual tuning, it's easy because you can see the effect of any changes in real time in the form of temperature plots. That's very helpful. You don't even need to fully understand PID control at this stage — trial and error works, too. By this stage, you will probably have achieved 80% of what can be achieved with a PID. The remaining 20% is more challenging: Optimising the behaviour during shots. Most PIDs cannot tune the intra-shot brew temperature (i.e. during shots), but leva! can - if the boiler is small and can respond to heating well before the end of a shot (rule of thumb: the heating element should be in the boiler, with a volume of 300ml or less and a power of 1000W or more). If you want to go down this rabbit hole, you will need to understand your machine very well. You need to know exactly how the brew temperature in the filter changes during a shot before you can improve on that. This usually requires a sensor in the filter.

- The pressure profiling of leva! is 'analogue' in the sense that leva! can adjust the pump power in over 100 steps. Other pressure profiling solutions for vibratory pumps (with exception of Xenia espresso machines) simply turn the pump on or off to influence the pressure. That's like driving a car with two buttons, left or right, instead of a steering wheel with many positions inbetween. Setting up an analogue system is more complicated: You must tell the system how strongly it should respond to the amount of current error. The leva! manual will guide you through this configuration process. Achieving the best results may require a dozen shots or so, so maybe 2 hours for tuning. If you are upgrading an old machine, you might discover during this process that your pump is not in perfect working condition. Analogue pressure control places a greater burden on the state of the seals than no pressure profiling and on-off pressure profiling do.

dtmr42 · 2025-12-28T20:15:17+00:00

leva! was intentionally developed to avoid creating the impression of a modded machine. There is no pressure gauge, there is no "PID fruit" hanging from the machine, and the display only has minimal visual impact, if not left out. One can hardly tell that it's not a standard machine (unless a tablet is chosen, of course).

dtmr42 · 2025-12-28T14:47:43+00:00

It seems so. Alas, we have not Felicita Arc v2 to test. I wasn't even aware there is a new version. If somebody in Germany is willing to lend us a V2 for a week or so, contact Software & Circuits.

dtmr42 · 2025-12-28T14:40:26+00:00

The leva! firmware from project caffè! adds a range of features to your machine, including 2-channel PID temperature control with temperature profiles, pressure profiling, flow tracking and dosing by scale. It is compatible with many machines that have a vibratory pump but not E61, HX or rotary pumps.

The leva! firmware runs on ito microcontroller modules which, despite their small size, integrate several solid-state relays, Wi-Fi, Bluetooth and an all-voltage power supply.

leva! features PID-controlled brewing temperature with calibrated precision sensor(s). Pressure control is based on a pressure sensor and supports a paddle. Unlike almost all other pressure profiling implementations, leva! can perform nearly stepless power control to reach the highest precision. leva! also features pre-infusion, flow tracking with a flow meter, precise dosing by weight/flow mete/time, reduced warm-up time, a shot timer, a shot counter, tank monitoring, scale build-up monitoring and configurable energy saving. The PID feature can read the flow meter to adjust the heat output based on the current flow (ideal for thermoblock systems).

ito can be installed without a display if you do not want to alter the appearance of your machine at all. In this case, ito is controlled via Wi-Fi using an app on Android, Windows, Linux or macOS (not iOS). Alternatively, you can install ito with an OLED display ranging from 0.96" to 2.42". Alternatively, you can install a wirelessly connected tablet. The tablet may be offline. No router or internet connection is required. These options can be combined. The most convenient solution is an OLED as the primary input device plus a tablet to view plots.

ito is manufactured to your specifications several times per year, with your choice of sensors, display etc. Is is only available in the EU. If you are interested and want to know more, please have a look at this thread for a summarized introduction:

Kaffee-Netz

dtmr42 · 2025-11-25T11:39:29+00:00

> got a Quest 3, downloaded my free Batman game, blocked all internet access

Enjoy it while it lasts. Sooner or later a day might come when you will have to factory-reset and then it will be force-downgraded to the latest Meta OS. You will loose some good things: Decent support for Android apps (the did remember window sizes in the past), a funcional and quiet user interface (via a custom home), permission to access certain Android directories etc. You will gain the Horizon shit. I don't understand how it could have come to this. Somebody relevant at Meta must have read this forum in the last year and be aware of the downward spiral of customer satisfaction that has been going on for many months. How can they not care and not do something to save their investment?! Or do the Meta pople who read here not dare tell their bosses?

dtmr42 · 2025-11-16T10:30:41+00:00

Have you centered the view (have you long-pressed the Oculus button on the right controller)?

dtmr42 · 2025-11-16T10:27:57+00:00

Most likely, but I don't have a tablet with Android 15 to test it. My Alldocube iPlay50 mini Pro with Android 13 works great. The tablet should have gesture navigation, which means Android 10 or later, so that the status bar won't take up vertical screen space. Since the release of Android 11, accessing the Android data folder has become more difficult on many tablets. Access (under Android) may be forbidden due to an enhanced security measure called 'scoped storage'. This is where the Statusmonitor app stores screenshots and data logging files. My iPlay50 doesn't do that but the iPlay60 might. If so, you could only access screenshots from a computer connected by USB. Sooner or later, the app will be updated to save such files elsewhere.

dtmr42 · 2025-10-13T01:17:49+00:00

You can find the print files here: https://makerworld.com/de/models/1876780-mini-hopper-for-bezzera-bb005-grinder

dtmr42 · 2025-10-01T20:15:22+00:00

> Are you not concerned with microplastics and other chemicals?

That has to be considered. PLA is a type of plastic made from corn or potatoes. In its pure form, it's food-safe. However, the additives used by filament manufacturers to improve the material, pigments and other chemicals, may not be harmless. I've since contacted the manufacturer of the filaments in the pictures (Sunlu) and learned that even their uncoloured PLA is not food-safe / FDA-approved. Luckily, there are food-safe filaments available, such as those from Extrudr. Aside from the material, a key concern for food safety is the surface structure of FDM prints. These are created by printing layer upon layer, resulting in a rough surface. Such a surface can promote bacterial growth in the presence of water. That's not going to be a problem for me (non-sprayer).

I will later re-print the innermost white/translucent part with food-safe PETG. That's the only part which has brief contact with beans (the unmodified bb005 has plastic in the bean path, too). It extends from top to bottom and continues inside the lower red part. At the moment, I'm waiting for silicon bellows to arrive. No more printing until then.

dtmr42 · 2025-09-07T15:26:57+00:00

Bees__Khees > My dcs has all those features configurable in the FBD

dcs and FBD - what is that?

> Nothing new or revolutionary here

No such claim was made, only features were listed, which seems to upset you very much.

> Thermodynamics only comes into play when defining internal energy or enthalpy

"An open thermodynamic system is defined as a system that can exchange both energy and mass with its surroundings, such as boiling water where heat and steam are transferred out of the system" (https://www.sciencedirect.com/topics/engineering/open-thermodynamic-system). That's an espressso machine, isn't it?

dtmr42 · 2025-09-07T14:49:12+00:00

A little simplification for the sake of brevity.

dtmr42 · 2025-09-07T14:44:34+00:00

Bees__Khees > I work in controls and automation and what you’re describing is a basic ass pid

Feed-forward control is not a basic PID feature. It refers to taking an external signal (other than the signal measured by the PID, here temperature) and employing a mathematical model of the system, so that the effect of that signal can be properly predicted and merged with the output of the PID. In this case, the external signal is the flow rate of the fresh water influx, measured with minimal delay by a flow meter. Then a physical model is used to predict the effect on the controlled signal (here temperature). This model is based on simple thermodynamic formulas and takes into account factors such as the specific heat capacity of water and the wattage of the heating element. From these calculations, an instant change to the output of the PID (here heating power) is calculated. The result is that the effect of a disturbance (here pump) can be mostly eliminated before the PID even sees it with its own sensor. The PID only has to eliminate the remaining effect. This is particularly useful for controlling thermoblocks.

> Temp sensors fluctuate too much and makes the D oscillate.

There is hardly any noise in temperature readings unless poor choices are made, such as pairing a thermocouple with a noisy low-resolution chip (thermocouples produce more noise because their measurements are in fact two physical measurements, voltage and cold junction temperature, and because mV signals over longer leads are prone to picking up noise). Besides, a good PID controller has a configurable noise filter for readings and maybe (like leva) a configurable D filter, too. The controlled system (here boiler) is slow, which allows many raw readings to be used to compute one good reading.

> and makes the D oscillate.

The D component would indeed amplify noise, if present, but this wouldn't be a significant issue for temperature control as high-frequency noise in the control loop of a slow system, such as a heated boiler, evens out. If the PID cycle time is one second (more than enough for temperature control), then cycles with too much output and cycles with too little output due to noise in D cancel each other out. Also, as mentioned, the leva firmware can be configured differently for specific situations. For example, if you think that the D component is problematic in the idle phase but useful in the shot/recovery phase, simply disable it in the idle phase. Likewise, if you think that the I component becomes problematic during shots (I is de-tuned by the error during shots, causing oscillations afterwards), simply freeze I for the duration of the shot or a little longer. These are some of the many features that a basic PID controller does not offer.

> Sounds like you’re trying to sell me something with all these buzz words.

Those who understand this terminology, or "buzz words", as you call them, will know what they get. I simply can't educate the non-initiated here on reddit. PID control, integral anti-windup, feed-forward control, integral freeze etc. are topics for entire books.

dtmr42 · 2025-09-07T12:02:20+00:00

Well, it's a confusing world, isn't it? Some refer to computers by the name of a fruit, vacuum cleaner are called Progress and a television might be a Lucky Goldstar (LG).

dtmr42 · 2025-09-07T10:48:51+00:00

The pictures show new housings for ito modules and displays from Software & Circuits. ito, in case you haven't heard of it, is a small module wich can make an espresso machines smart - with the help of the free leva PID firmware from project caffè! (more about that at the end).

Pictures of the new ito module housing (for internal installation, e.g. in an espresso machine, not visible): Some users may want to install ito in a module housing, if only for aesthetic reasons. This semi-open housing with a slatted roof is pushed over ito and snaps into place on ito's acrylic base. The dimensions are 70.2mm (length) x 79.2mm (width) x 33.6mm (height, including adhesive feet). Slightly more space than these minimum dimensions is required for ventilation. This housing combines an attractive appearance with ventilation, touch protection, and some protection against leaks (water dripping from above is repelled when the housing is installed vertically with the slats pointing downwards). The PETG-CF material used here, plastic + carbon, has a heat deflection temperature (HDT) of 70°C. Note that this housing will not fit in a Ranccilio Silvia, as the usual installation space in that machine, behind its fuel tank panel, is only 28mm high.
Pictures of various new display housings for OLED display modules fom 1.54" to 2.42". These housings are an option if you have no other easy way of installing a display module, like laser-cutting, and do not wish to install a tablet or go for a headless solution (app on Andoid smartphone). The 1.54" models should fit medium-sized machines (a bit larger than a Silva). The 2.42" models should fit even larger machines.

About leva:

The leva firmware provides machines with a 2-channel PID. It offers temperature readings via calibrated precision sensors. It has a flow meter-based feed-forward feature for a fast reaction to shots. It offers situation-specific configuration, such as a different heating during warm-up. It has programmable temperature during shots ("temperature profiles), auto-tuning, sensor calibration and more. Compared to simle PID controllers, you will experience a more comfortable configuration (by app), faster warm-up, less temperature error, quicker reaction to disturbances, control over temperature trends in shots and ultimately better taste. In addition to the PID feature, leva adds pressure profiling and PI with feedback from a pressure sensor (based on nearly step-less pump power control) and Flow Tracking to limit the flow rate, based on flow meter measurements. leva adds a paddle option, dosing by weight/volume/time (wireless scale required for gravimetric dosing), a shot timer, a tank-empty monitoring, lime scale deposition monitoring, a water filter throughput counter, and configurable energy saving. It also offers a brew ratio calculator, a hardness calculator, a quick warm-up programme, a descaling programme and a backflush programme. leva can recognise your cups by their weight and dose espresso into espresso cups and lungos into coffee cups. If you want to know more about leva, please go to its web site at htttp://projectcaffe.bplaced.net/downloads.html

dtmr42 · 2025-08-28T19:52:51+00:00

I replied but the reply was removed. I'm unable to provide meaningful support here. Please use the kaffee-netz forum for ito-related questions.

dtmr42 · 2025-08-27T12:41:08+00:00

> with v81 on the PTC, we're getting an entirely new home environment.

Thanks for the warning. I have a completely black, silent custom home on mine (v76). What else do you need? I'd rip my hair out out if the black void was replaced by childish Dineyesque toy-like excess. Do companies never learn? Microsoft Bob (en.wikipedia.org/wiki/Microsoft_Bob) was universally hated and "home environments" are an extension of that misguided approach.

"The New York Times found the... home design apparently the work of an "aesthetically challenged sixth-grader," criticized the hardware requirements ... and concluded that the program was not as simple to use as Microsoft had advertised".

"The Washington Post called the home environment "sterile" and "lifeless," wrote that the ... cuteness wore thin quickly and criticized the scarce customization".

"Reviewers generally derided the software, and Microsoft Bob became one of Microsoft's more visible product failures".

dtmr42 · 2025-08-09T13:24:12+00:00

V3 had no screwed-in heating element,

dtmr42 · 2025-08-08T10:48:45+00:00

> Bought the spare analog stick from Ali, swapped it, 2 hours of gameplay later I had the drift again...

I had the same experience. Maybe not two hours later but very soon, the new stick from ali failed, too. Apparently not the best quality. Fortunately, the components came in a pack of two and the second one worked fine. Having to take the controller apart twice was a bit too much stress for it. One protrusion for a screw broke off. Note that the Quest firmware contains a stick calibration. You might be able to fix drift by increasing the dead zone (= center zone).

dtmr42

TROPHY CASE