Philips 3200 Coffee Machine - part 1

About a year ago I bought a new automatic coffee machine to replace the aging Saeco. This is a Philips machine, 3200 series, which actually is a pretty close match to the Saeco. Not a surprise, since Philips is the parent company of Saeco, while Saeco is the parent company of Gaggia. Which means some parts could be interchangeable.

I waited for about one year to see if any problems develop with the machine, but so far it has been pretty reliable. This post will aim to compare the old and the new machine and figure out how to automate it.

Just click on the Saeco label or search this blog to see the old teardown, which thousands of people have already read.

There will be plenty of pictures after the subjective review.

Disclaimer: I don't work for Philips or any other coffee company, this is just a hobby. 

Software and usability

The new machine is much better in terms of software and friendliness. While the old one used to dump ground coffee whenever it felt something wrong, the new one waits for the user to correct the problem. 

For example, if water is running low, the machine will pause during coffee making and wait a few minutes for the user to top up the reservoir.

There is a count of how many coffees have been made, this is pretty accurate, which will trigger a prompt to empty the dregs drawer and waste water container. You cannot fool it by just taking the drawer out and putting it back it, it needs to be out for at least a few seconds.

Water quantity and temperature are now user-adjustable and documented through the manual.

Pre-ground coffee can be used now, which the old Saeco lacked. The usage is not very intuitive but also not hard to figure out, even without the manual.

The "out-of-beans" sensor is now out, but I don't think many people will miss it. Moreover, the machine will just make a coffee with the already ground beans, instead of just dumping them out.

Descaling is semi-automated and works really well.

Can't say much about the frother, couldn't make it work properly, even after trying at least 10 times.

The touch button sensitivity is really bad. I realize that it's less sensitive for moisture reasons, but it could have been implemented a bit better. You need a "magic finger" touch to perform any action, since the firmware is aggressively tuned to reject false touches.

Noise (loudness) is pretty bad, it has to be one of the loudest consumer device I've ever heard. The grinding noise can be somewhat reduced by keeping the beans container full and pressing the lid. The pump noise can be reduced a bit, read below how I did it. It helps if the machine is put on a soft mat (extruded polystyrene).

Maintaining the machine, especially the daily tasks (emptying the dregs and waste water) is much cleaner and streamlined. Also the footprint is quite a lot smaller. I like the automatic powerdown feature which can even be configured.

All-in-all, I think there were some unnecessary build costs that were cut down but overall there are definitely improvements.

Teardown (disassembly)

This is not necessarily a guide on how to disassemble the machine, just how I did it. My main reason was to get to the board controlling the touch buttons. Most users will not need to do this and is probably one of the hardest parts to remove anyway.

Front panel

You can use a spudger and guitar picks to separate the chrome piece.

The front panel assembly should then just slide out, held back by a ribbon cable.

The board is marked "Omnia UI Basic". The microcontroller handling the user interface is CY8C4025AZI-S413 - it's a Cypress PSoC 4000 ARM M0+ with a lot of features. Of note are the low-voltage operation (1.7V) and CapSense.

The board layout is easy to follow and the silkscreen is quite useful. It communicates with the main board - which is somewhere deep inside the machine - via UART at 115200 baud. Below, I've just soldered some wires onto the connector and studying the signal shapes with a portable oscilloscope.

The protocol is mostly decoded but that will have to wait for a future post. 

Top and side covers

Leaving the front panel away from now, to service the machine the top panel needs to be removed. The screws are inside the beans container, with the last one hiding inside the "mushroom" thing. 

The mushroom top covers the grinder and I assume it functions as both finger guard as well as a beans "spreader", so that the grinder sees equal loading.

You can see the grinder adjustment higher up, this works the same way as with any Saeco machine. Mark down the position when you are taking the top off, since it's not keyed.

The dark protrusion even higher up would be a place for the magnetic lid sensor, which is omitted from this machine, probably in order to reduce costs. So you can run the machine without the lid, though it makes quite a racket when grinding.  

Most of the screws are Torx T10. The silver ones are stainless, while the dark ones are just plain steel. In addition to the screws on the top, there are some in the back and in the front of the unit, pretty easy to spot them. They are mostly all the same size.

Underneath the top sits the funnel and grinder assembly, with motor. Just be careful when removing it, everything might still be loosely attached.

Below is the complete grinder assembly in view. Top left is the grind adjustment, which hopefully you will remember to put back in the same position. It works by rotating the big toothed wheel which spins the ceramic grinding plates closer together or further apart.

If you find that your grind is too coarse or too fine, you can remove the top adjustment knob and insert it into another position, at your own risk.

There are some markings on the wheel, I think the red dot is for the coarsest grind, the white line for the finest.

The rightmost part is where the ground coffee goes, whether from the grinder or from the pre-ground funnel in the front of the machine.

The motor now lacks the speed sensor, which previously enabled the machine to know if it was out of beans or if the motor was stuck. Again a cost reduction, though there is a connector on the bottom of the grinder. I did not test the points, but the sensor might be there, just not used.

Removing the top cover and assembly completely reveals nothing of interest. The grinder sits on a spring, I've raised mine up a bit, with some felt pads, to help reduce noise.

Behind the back cover is where most of the stuff happens.

Top left is the main controller and power board.

Bottom, from left:  water meter, solenoid valve, water pump, boiler.

Left side (when viewed from the front) has the solenoid valve for the frother.

Below the black cover is the motor for the brew unit, with just a limit switch. I think the old Saeco had 2 limit switches. Otherwise its functionality is the same.

The right side has the place for the brew unit and the water tank. I think the new design is an improvement, since the waste water can run directly into the drawer below. If it overflows, it runs below the machine, without accumulating inside and causing rust and mold.

An issue with the old machine was that many screws were exposed to this damp environment, causing them to rust. In the new design, there are a lot less screws and less places for dirty water to accumulate.

Noise mitigations

The grinding adjustment can vibrate while the machine is in use, It comes apart in two pieces and I've used some heatshrink tubing around the top part. You can also use some rubber tube, being careful not to go below the clips holding it to the bottom part.

Notice that the knob is not keyed, so when assembling the machine you should make sure it faces the same angle as it did when taking it out.

The grinder has a few "soft" locating points, but mine was missing one. You can see that the right side of the motor has a rubber pin, which is missing from below the adjustment wheel. I used a toothpick to prevent the unit from sliding around.

Note that you don't want to over-constrain the assembly, it's designed that it can move around, though in my case it had too many axes of freedom.

As written above, below the grinder there is a spring which was barely making contact in my case. I used some felt pads to raise (stiffen) it.

The mushroom top also vibrates a lot. I put a tiny bit of heatshrink tubing at the top of the screw holding it.

Part 1 conclusion

This was just a quick teardown for people who are already familiar with these kind of machines. Look into my other articles for detailed explanations and troubleshooting.

I've reverse-engineered most of the protocol of the front panel and will try to integrate it with Home-Assistant and ESPHome. There is some handshake/heartbeat happening which will need debugging, since this determines whether I need to deactivate the front panel or can just wire my circuit in parallel. Either way, should not be rocket-science.

I believe my model has most of the features available, so people with lower-end ones can potentially upgrade to gain extra functionality, since those are probably determined just by button availability. Having full software control means that you can emulate non-existent buttons.