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decent_espresso

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  1. New: zoom in on your espresso chart These two changes described in the video hopefully address two issues: - two separate Y axis (for pressure, and for flow) was complicated to understand - zooming allows you to get close to the details you want to see -john
  2. New "total espresso weight" line in Decent Tablet App Here is a picture of how the "total shot weight" charted line looks when making espresso. It's the thin brown line you see starting from zero around 20 seconds into the chart. The weight is divided by 10 (ie, 1= 10 grams) to fit on the same Y axis as everything else. I haven't added this feature before, as I wasn't sure what its use would be. However, with Scott Rao Scott Rao's "blooming espresso", I've found that tracking and controlling the amount of dripping that occurs before the pressure rise, is very relevant to the final drink quality. Generally, about 5g to 8g of "drippage" yields the best flavor for me. I've previously tracked this by hand, by looking at the scale as the shot proceeds. With the new "total shot weight" line, you'll be able to see the shot weight at each stage, later on. Seems helpful. Some remarks about this: the thin brown line is enabled by default in the zoomed view, but not in the small-charts view (the default view) so as to avoid visual complexity in day-to-day espresso making. an interesting thing to note is that the shot stops at around 27g, and the final cup weight was 33.5g. This is because, once the water stops and pressure is released, there is still some flow from the puck to the cup (about 5 grams' worth) Also note that I've halved the smoothing in the weight line, from a "2 second window" to a "1 second window". The downside of this change is a slightly more jittery brown line, but the upside is that the brown line moves twice as fast toward the real weight. This is helpful when you're comparing the brown line (flow into cup) to the blue line (flow into puck) to judge the success of your preinfusion stage. I've got the latest code running on my main home espresso machine. Once it seems solid for a few days, I'll release this publicly. The upcoming tablet version release will also include the "allow yourself to start espresso only if the scale is connected" optional feature. QUESTION: should the zoomed espresso view automatically scale the Y axis appropriately, once the shot has finished? In the chart above, the Y axis would have scaled to 9 bar, instead of the default 12 bar. The downside to doing this would be that 1 to 1 comparisons between charts will be more difficult. The upside will be a more zoomed chart that is easier to read detail from
  3. Just FYI, as of August I have my own full time employee in the mainland, whose job it is to inspect everything before they ship to us. She was at our chassis fabricator yesterday. Here's the kind of thing she's doing, and posting to our internal basecamp forum.
  4. Unless they've only just got to the end of the first batch of parts with high failure rate they got lumped with. What actually happened is that our first batch was 350pcs, 2 years ago, with lots of problems. But, we ordered right around Chinese New Year, which was a mistake as factories bring on temporary workers then to deal with the order rush, and (we learned thereafter) quality goes down. Don't order anything from China that needs to be delivered within 60 days of Chinese New Year. It's a 3 week holiday there, and a mad rush. The PCB manufacturer said that in the next order, quality would be much better. We ordered 750pcs, and quality was not much better. We just finished using up that batch. From the new manufacturer, over the past 2 weeks we've tested them all ourselves, and out of 175pcs of 1st delivery, 3 were defective. 1 was a solder problem, 2 were defective components from the supplier (a bad crystal, a bad MOV surge protector). Note that we buy everything from Mouser, a huge part supplier, not a dodgy intermediary, so that we know what we're getting. The new 1.7% failure rate is much better than 30% (!!!) -john
  5. There's a back and forth negotiation with any custom parts supplier, with the buyer wanting to put as much risk on the supplier, and the supplier resisting. I've learned that the way suppliers like to work is for there to be absolute clarity as to what is acceptable. We have to forecast all possible defects that we'd reject. A "testing rig" that gives a GREEN or RED light, that we make and provide to the supplier, is the preferred way. But... this takes time to create, as well as the passage of time, to learn what needs to be tested. Anyway, in no way am I arguing with you (grin). I'm just explaining here, the story of where's we're at, and where we're trying to get to. -john
  6. If only it weren't for this: 😪
  7. Sorry, I don't understand your comment. How is what I wrote above, reducing quality?
  8. Decent Espresso on Telegram Matt Perger recently announced https://twitter.com/mattperger that he was moving to Telegram https://telegram.org/ the secure instant messaging alternative that has recently been quite in the news. Never to miss a trend 😀, I decided to start a Decent Espresso Channel https://t.me/decentespresso on Telegram. Some other channels I can recommend: The Matt Perger Channel https://t.me/pergfect Coffee Ad Astra by Jonathan Gagné https://t.me/coffeeadastra Raw Materials Channel https://t.me/raw_material_coffee You can also message me directly on Telegram at https://t.me/johnbuckman
  9. I'm not really sure what you're suggesting. Our entire order of (say) 750pcs is delivered to us, all at once. Once delivered, failed PCB are our problem. In order to avoid this, the PCBs need to be tested before they leave the supplier's warehouse.
  10. Testing at the source One of the things we've discovered, as we've learned "how manufacturing works" is that if you've ordered something custom-made, once it's in your hands, it's your problem if it doesn't work. All contracts stipulate that responsibility ends as soon as the item gets loaded on a truck. For the past two years, we've had our PC boards made by a company in Shenzhen, where almost all mobile phones in the world are made. We've experienced defect rates between 15% (the AC board) to 30% (the DC board, aka the "computer"). At $50 each (approximate), that's (150pcs x $50) + (300pcs x $50 = $7,500 + $15,000 = $22,500. Ouch. This high defect rate forces us to over-order each part, so that after quality-checking, we have enough parts to make our goal quantity of espresso machines. Part of the cause of the high defect rate, is that our quantities are considered small. Anything under 20,000 pieces is small in Shenzhen. We're ordering 300 to 750 pieces, so we're "real small". These small order quantities mean that it's easier to do a lot of the work by hand, instead of by robot. And by hand, means lots of variation, and a high error rate. For our upcoming v1.3 espresso machines we've changed to a Hong Kong based company called PDSTE, who is based in "Science Park", an incubator for tiny high tech companies. For PDSTE, we're a huuuuge client, which is a nice change! And... everything they do is 100% by robot, because in Hong Kong, labor is not cheap: about the same as in the USA or EU. It's either Robotic or it's not Made in Hong Kong (well, except for our Decent Espresso Machines). So... as part of moving to a local supplier, we've built a "testing computer" that is essentially everything the espresso machine is, but as a single board computer that does nothing but run the tests. We're building a few dozen of these test boards, so that PDSTE can test our "espresso computer" before they deliver it to us. Crucially, any board that fails at PDSTE, before it is delivered to us, is *their* problem, not ours. So, it's in our interests to make this test as thorough as possible. For each board to test, all the sensors, pumps, valves and more are connected to the board that needs testing, and then the test board connects to that. Then.... all the lights go GREEN or they don't. If they don't, they can't be shipped to us. This also highly motivates the manufacturer to reduce their defect rate, as they feel the pain of each defective board, to the tune of about $35 in parts that they just lost, not to mention their labor cost. When we started down this path almost 5 years ago, we knew nothing. We're slowly learning. -john
  11. DE1XL Suitcase Prototype I just received my DE1XL in some hand-cut foam to see if it could travel well in our suitcase. My goal is to make the slightly-larger and more capable DE1XL model as transportable as our DE1PRO and DE1+ models. Here, we're also trying new protective corners, made out of hard plastic. And a new, more opaque back panel for the white model, so that the magnets don't show through. If we can pull this off, we'll be able to use the same suitcase, but with different foam, for all our espresso machine models. And I'll be happy to send (for free) the updated foam to those of you who already bought our DE1XL model. FYI, the DE1XL (launched in March 2019) now represents 18% of our machines sold, almost 1 in 5. -john
  12. iPad & Mac demo - running the Decent Espresso App In this video, you can see the Decent tablet app running as a "web browser app". This allows you to run the app from any device that has a modern web browser. In this demo, you'll see me use the app from my Mac, and my iPad. A Z button floats on screen to zoom the app in your web browser. This works both on my iPad and Chrome on my Mac. You can choose to go completely full screen, or just full-inside-the-web-browser, by repeatedly pressing Z. A K button floats on the screen of the iPad and Android tablet (under web browser use) to show the on-screen keyboard. Still to do: you need to run the tablet app on a computer (windows/mac/linux), which then broadcasts the app through a built in web page. So... you need a computer around. at the moment, running the app on a computer means it doesn't use bluetooth.... which means it can't yet actually control the espresso machine. That's getting addressed in two ways: future bluetooth support in the app on windows/mac/linux, and USB support via Reed Taylor's DESIRE accessory I'm fairly sure that by using Jasonelle https://jasonelle.com I will be able to make a native app on iOS that automatically launches the Decent app on your iPad. See https://www.freecodecamp.org/news/how-to-turn-your-website-into-a-mobile-app-with-7-lines-of-json-631c9c9895f5/ - that will be a little bit more convenient than loading a web page in Safari. Typing on iPad does not work right. Typing does work from a computer or from Chrome on Android, but not on iOS. This is the only major bug I observed. A minor issue is that the web app is a bit dimmer than when run natively. I'm working on both those issues, but neither is a deal-breaker.
  13. Bigger BROR IKEA Coffee Cart Progress Report I've wired and plumbed everything into my Bigger Bror cart. Here's a quick tour. Here is a link to a shopping cart with everything that is on my coffee cart: http://tinyurl.com/yy2o9lmm except for these parts, which you will buy elsewhere: Niche Grinder: https://nichecoffee.co.uk Brown microfibre rags https://www.amazon.co.uk/gp/product/B07RL36KMV/ BROR 110cm : https://www.ikea.com/us/en/p/bror-work-bench-black-pine-plywood-30333286/ (optional) wheels for BROR: https://www.ikea.com/us/en/p/bror-utility-cart-black-pine-plywood-60333850/ -john
  14. Announcing DAYBREAK Decent Owner Reed Taylor is working on DAYBREAK, an accessory for Decent Espresso Machines. DAYBREAK plugs into our standard communications port, replacing the bluetooth module that's placed there by us. The bluetooth module then plugs into his board. Here is what DAYBREAK does for you: it is a full featured Linux computer, that can fully control the Decent Espresso Machine It runs a Javascript API, and a web server, so that people can remotely control their espresso machine from their own apps. It can run the tablet app I've written, and present it as a full-featured web app. This allows you to run what is now the "Android tablet app" on any computer (iPad, Windows, Mac) from your web browser. There is a USB port on Daybreak, so you can plug your own computer in. A number of robotics projects are underway with the Decent, and wired-control is much preferred over Bluetooth for reliability. My tablet app becomes fully functional on Mac, Windows and Linux, thanks to the USB connection. Previously, it was mostly functional, but lacking the Bluetooth functionality to actually make coffee. The USB interface is *much* *much* faster than bluetooth, and can access all the internal sensors and data, at much more useful speeds than bluetooth could. Reed's plan is for his DAYBREAK board to be something you can simply buy and plug into your espresso machine. You won't have to be a tech genius to use it. A tablet app update release I made a few weeks ago, solved the outstanding bugs with this approach. Reed still has problems to work through before it's ready, but his progress has been steady and impressive. - john
  15. ShinTV: going to the SSP burr factory In this episode, Shin visits Hansung Lee , the CEO/engineer/mastermind behind SSP burrs, gets a tour of the factory, the burrs, and sees how Hansung uses his DE1 to test burrs and grinders out. These burrs have emerged in the past two years as "one of the top 3 in the world" and many feel they are simply the best. Interestingly, Hansung's only complaint (the USB cable) happens to be the subject of my previous post today. -john
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