John

Are you looking for the two stage setpoint, or are you looking for more power? The 200 and 250 are limited by the fuse on input current, the 75 by output voltage, and the 60 by thermal margin. So we could conceivably add the functionality, but it'd be limited to the nameplate max power of the boards. Is that worth adding?

You're charging and your battery is noticably low. If you turn the power down to 1 watt (which the charger can handle without the battery at all) does it stay on? My money's on a bad battery or bad battery connection.

We have an early internal beta going for a Linux version. So it isn't outside the realm of possibility eventually. But it's more of a "work on this when there's a free moment" project rather than a high priority, so no timeline for it.

Sadly, the PMTA mandatory date changed to 2022 but the grace period date is still August 8 of 2016.

New features on existing hardware will be international only as long as the FDA prohibits changes past August 8 of 2016.

Are you reading high or low for cold ohms? Also, is your 75C theme using cold ohms, or cold ohms at 70F, which we just exposed in SP 25? The reason I ask is all the previous DNAs display the 70F cold ohms by default, whereas the 75C displays the raw sampled cold ohms. So it isn't exactly apples-to-apples unless you happen to be at 70 degrees ambient with good case thermals. If you are letting the device do all the work, then the two are functionally equivalent. However, if you are using the 75C's ability to manually adjust the ohms, especially if you are manually adjusting them to match the measurement from a 250, then it is important that the theme be using the newly exposed 70F field.

(I don't post here much, but I am... Intimately... Familiar with what Evolv did.) This is actually a really clever way to get around the power throttling as you describe it, while still effectively getting an automatic (and adjustable) setpoint and keeping temperature below a hard cutoff. This is much closer to how we initially envisioned TC being run (which is why there are both power and temperature limits, rather than just having a temperature setpoint.) That said, the preheat on a 75C is a proportional control, so if your power setpoint is significantly lower than what you need to maintain your vape, like you have set up here, then you're going to get some steady state error. Your original trace needs about 40W to maintain that profile. The difference between the 27W coming from the power setpoint and the 40W coming from the preheat is being added by the preheat term, and that has steady state error by design (so it doesn't drive the system to overshoot temperature and power.) So, you're doing everything right, but if you want it to hold closer to the preheat temperature you need more oomph from your main power setpoint. You don't have to crank it up so much that you get blast-and-die-off vapor production though. Hope that makes sense and helps, John

Lee, you have to have your power setpoint at or above where the coil wants to run to be running temperature controlled. As is you are running wattage controlled with an extra (permanent) boost from the preheat. If you set your wattage to 60 or so, you'll hold temperature.

Do the tcr curves match? Also what are the mod resistance set to?

Send it in and we'll get whatever is going wrong fixed up for you. We're pretty liberal on what we will consider as covered under warranty.

Okay, so it is now reading stably, the room temperature is a little hot but not enough to cause the effect, it just seems significantly miscalibrated. More than I've seen yet. But the A/D sampling changes we put in could have affected the calibration (which if so would be the easier fix than finding the sampling issue we had) If you manually adjust the resistance on the 75C to .500 ohms, does it vape the same as the other devices? Similar smoothness, similar power, similar device monitor graphs?

No, case analyzer works correctly (finally) in this version. There's a bit of discrepancy depending on whether your theme charges with the screen on or off, but that's a couple degrees at most. However, the default case thermals for the board are definitely wrong in most devices. So changing them manually to approximately what I posted above is recommended if your room temperature is significantly off. We'll push a device-specific update when these changes (and any others that show up while testing this one) get pushed to all users.

Gotcha! Three questions: .460 vs .500? I know it doesn't seem like much of a difference, but like you say stainless is really sensitive. In atomizer analyzer, what are each reading for room temperature and raw resistance? What mod resistance do you have set for both devices? Is it now stable to vape on (just cold) or does it still have the same instabilities? If it is reading stably, then we can now chase down the missing .04 ohms.

To make sure, you're talking about SP 23 that went up Thursday? If so, it shouldn't exactly change the initial reading. What it should do is make the initial reading a lot more stable (less variation from sample to sample, or if you run atomizer analyzer) and it should fix a lot of the stainless steel control wobble. It may help the firing output. It also significantly improves how the case thermal are computed but only if it gets new coefficients. For starters, try 500 seconds cooling, 400 seconds heating, 8 degrees static and 18 degrees per amp. That should keep the room temperature reading pretty accurate. What are you reading for a cold resistance, what material, and what should you be reading?

If you are always or usually in a temperature controlled environment, try setting the max ambient temp and min ambient temp to a narrower range. 68F to 72 if you are always in AC.

We found and fixed the firmware bug that could cause this with some combinations of atomizer resistances and settings. The good news is the error was in firmware, so installing SP 21.1 fixes the problem. The error has been lurking for a while, but really only manifested itself badly when we corrected the overvoltage case throwing check atomizer rather than limiting the output recently. The bad news is if the clock already took damage due to the bug, like in your case) the damage is in hardware and you will (eventually) need to have the RTC chip replaced. That's covered by the warranty of course. Fortunately there are VERY few of these in user hands yet, so the extent of the problem should be limited.

It sounds like we need to make default thermal settings for our manufacturers and leave the values somewhere. (And get the manufacturers to update them in their production programmer settings) I think we have one of each of the 75C devices you can buy at the Mone, so we should be able to do that this week. In the meantime, if you run case analyzer and it fixes the problem, could you post what values you got and what device that was in? Thanks!

We were able to replicate and correct this, the fix will be in the next service pack.

More likely to be a minor bug in the software (there are two hardware comparators, one looking at over-the-counter and one looking at over-current) The hardware of the DNA 75C is fairly similar to the regular 75, except for all the added components for puff recording and timing and running the screen and storing the configurable UI etc. But the software is a completely new codebase. It's probably just interpreting or displaying the error state wrong. We'll add that to the list of small bugs to clean up, but I wouldn't worry about it too much.

There's a 3.5 volt test pad on the board you could tie into. Be aware that when the device is hard sleeping (after an hour or so unplugged) it will turn off. Pressing the fire button or connecting USB will turn it back on. If you have the board oriented with the fire button at the top and the taps at the bottom, it is the round test pad just above the UP tactile switch on the right edge of the board. For ground, use the B- pad, the output ground or any of the mounting holes. Anything except the GND tap. Hope that helps John

Have you tried a different 1A charger? It's possible that the signal coming out of that one isn't clean (could have a broken capacitor inside or some such) Is this a vaporshark board or the standard board?

This seems like it would be a pretty good theory, but everything you're seeing is normal and won't/cant pop the fuse. I'll walk you through it: The USB can absolutely provide power to the battery terminals. Otherwise it couldn't charge. However, if the charger isn't active then it can only provide up to USB voltage to the battery, and there's a diode in the path, so as long as the battery input (after the fuse) is greater than 5V power doesn't go that direction without the charger on. With the charger on (and the fuse intact), what the charger... does... is generate a controlled voltage from the USB input that is higher than the battery voltage, and then feed that into the battery. Basic battery charging. It uses the tap to read the battery voltage, so if your fuse is already blown but you have the tap connected, it will see the battery there and try to charge it. Won't be able to, of course, because the fuse path is gone, so the power will get dumped into the overvoltage protection diode. This will heat the board, so I don't recommend it long term, but it won't pop fuses. In this scenario, as long as you're asking for less power than the USB port can supply, it will quite happily fire from the generated battery voltage for a short period of time. Basically the input capacitors acting like tiny batteries. In no circumstance can any of this blow the fuse, though. No USB port on earth can supply the 25 amps it takes to pop a fuse. So I'm not 100% sure where the question is. You're describing what would be normal operation in a degraded state (battery positive not connected, battery negative connected, taps connected, USB connected) Hope that helps John

The font is a slightly pixel-modified raster version of FFF Alpine.

Not my current development focus, but I imagine something like that will happen sooner or later. The nice thing about technology is it rarely goes away.

Virtually none below that threshold (430 to 450 actual coil temperature) depending on the juice and atomizer construction.