Transparent Roaster wrote:Does anyone know if the Artemis board will charge a battery without any problem?
This Sparkfun description says the lipo battery needs a special charger...
the battery link:
https://www.sparkfun.com/products/13851
the charger link:
https://www.sparkfun.com/products/15217

It has a charging circuit on board so my guess is the answer must be "yes".


https://cdn.sparkfun.com/assets/6/f/0/5 ... ematic.pdf

Yes it charges a battery fine from USB-C with no special charger need. Read the assembly manual on the Wiki for more info, including getting the polarity right.

One thing to take care with is the assembly of the glass. I had a problem with decreasing Jagtron value that I thought was due to temperature change or perhaps the coffee decomposing. I eventually discovered that my glass had become partially disconnected on one side and was acting like a spring: pressed down very slightly with a new sample and then slowly rebounding over time. I reglued it but I expect it will eventually come loose again without some means of pinning it into place. I'm trying to figure out a way to make mine more reliable.

Apparently, from looking at the Discord discussion, I'm not the only one who has experienced glass attachment problems.

The sensor board is also anchored on only one side and the entire lid even deforms with some pressure. I think there is a version 2 of the enclosure in the works.

jpender wrote:The sensor board is also anchored on only one side and the entire lid even deforms with some pressure. I think there is a version 2 of the enclosure in the works.

Version two is ready and I am using it.

I can do a version 3 that will hold the glass in place if there is demand.

Here is version 2, which holds the sensor in place quite well:

Where are those files located on github?

jpender wrote:It has a charging circuit on board so my guess is the answer must be "yes".

Brewzologist wrote:Yes it charges a battery fine from USB-C with no special charger need. Read the assembly manual on the Wiki for more info, including getting the polarity right.

Thank you for verifying that. Time for the battery upgrade.

jpender wrote:Where are those files located on github?

I'm still not good at navigating github, so I sort of stumble onto the files every time, but they are in a branch of a fork.
The fork is PatrickFrN, and the branch is Parametric-3d-model
You want the sensor tray and the lid that goes with it.

https://github.com/PatrickFrN/roast-met ... Parametric

Thanks!

I'm not github literate either.

Quick update:

1) Tests continue comparing the DIY meter to reference meters. Even Morten Munchow has one that he's comparing to other meters. I think the DIY meter is reading ~8 points higher than other meters currently, but the standard deviation is low which is good. Nothing conclusive yet, but grind size matters. A grind just above clumping is generally still recommended.

2) One of the great things about open source is anyone can contribute. Out of the blue someone dropped code on GitHub that uses the Bluetooth chip in the DIY meter to communicate to a web browser you can access from a laptop or droid phone. It currently just displays Agtron and raw readings, but plans are to show other data, and to write calibration settings entered on the web form to the DIY meter's EEPROM so there will be no need to recompile code after calibration. Some are also planning to use this foundation to create a Tonino-app like feature that lets you create your own scale.

3) Another recent finding is if you set adcRange=16384 in the code, instead of a one point change in ledBrightness moving the Agtron reading 6-8 points, it now only moves it 1-2 points, allowing more precise calibration. If you make this change, aim for a reading of 230 Agtron with baking soda using an ledBrightness=125 to start.

Good stuff. I loaded the 1.0.1 code with the 15384 adcRange setting and calibrated with baking soda with a LED Brightness ending up being 133 for a reading of 130. I played with one batch of coffee on my Aillio Bullet pulling the trier before first crack, at first crack, and a few points after until the end of the roast to play with. Since it only takes a few grams plus some to purge the grinder with for a reading I think I'll just pull a trier at first crack going forward and measure that and the end of the roast.

I'll have to play with the BlueTooth version, being able to change the calibration from the browser in the future sounds pretty good.

My RoastMeter reading at first crack of the Ecuador Finca Terrazas del Pisque gave a reading of 114 and the final reading 15 degrees C from that was a reading of 77.