Search found 659 matches

by JimG
October 12th, 2014, 10:55 pm
Forum: Coffee Roasting
Replies: 164
Views: 22602

TC4 + HTC roast controller for Hottop available

The insulation system consists of an outer jacket over individual insulation on the 2 lead wires. The jacket may or may not continue inside the metal sleeve, but the insulation on the individual wires goes all the way to the tip. For this reason, the insulation on the lead wires should really be abl...
by JimG
September 6th, 2014, 9:22 am
Forum: Coffee Roasting
Replies: 5
Views: 895

TC4/Artisan error: list index out of range @line22074

Those are the calibration parameters for your board. They are loaded into the EEPROM on the board and help fine tune the readings from thermocouples. Jim
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by JimG
September 5th, 2014, 6:22 pm
Forum: Coffee Roasting
Replies: 5
Views: 895

TC4/Artisan error: list index out of range @line22074

Which version of the aArtisan.ino sketch do you have loaded? Prior to version 3.00, the serial rate was 19,600 baud. Version 3.00 upped it to 115,200. Are you using TC4 shield + Uno, or TC4C? They will show up slightly differently in the Windows device manager. Jim
by JimG
August 21st, 2014, 4:39 pm
Forum: Coffee Roasting
Replies: 9
Views: 1528

Artisan suggestion: ROR(ROR)

Even if the temperature resolution could somehow be made perfect, I believe that individual beans striking the probe might jostle the readings enough to spoil 2nd derivatives estimated in real time. Jim PS - I saw the horse move, honest
by JimG
August 20th, 2014, 10:23 pm
Forum: Coffee Roasting
Replies: 9
Views: 1528

Artisan suggestion: ROR(ROR)

You guys are dreaming The function (BT, in this case) is very noisy to begin with. A significant amount of digital smoothing, with the associated lag, is needed to make the first derivative, BT', usable. The amount of smoothing that would have to be applied before performing the numerical differenti...
by JimG
August 18th, 2014, 8:11 am
Forum: Coffee Roasting
Replies: 3
Views: 929

Puzzling Probe Problem

If possible, electrically insulate the probe from the roaster body. Or try an ungrounded probe. Not sure this will fix the particular problem you are having, but I have seen it fix many similar problems. Might be worth a try. Jim
by JimG
June 12th, 2014, 5:06 pm
Forum: Coffee Roasting
Replies: 16
Views: 968

Artisan statistics question [SOLVED]

J-type is more sensitive than K, i.e., it generates more millivolts per degree. So if your meter is set for J, and you feed it K, the meter will significantly underestimate the actual temperatures. Jim
by JimG
May 29th, 2014, 6:00 pm
Forum: Espresso Machines
Replies: 10
Views: 1757

Bitter Shots: Rancilio Silvia (PID)

Grinder? Jim
by JimG
May 11th, 2014, 8:38 am
Forum: Coffee Roasting
Replies: 31
Views: 6471

Great Hottop Modifications

It's not the resistance. Instead, it is the result of creating a new "junction," in thermocouple lingo. The problem is that this new junction is away from the circuit board and therefore will not be the same temperature as the circuit board. This puts some extra error in the readings
by JimG
May 10th, 2014, 8:32 pm
Forum: Coffee Roasting
Replies: 31
Views: 6471

Great Hottop Modifications

They are JST connectors, XH family. Put as little new copper wire between the ends of the thermocouple leads and the circuit board as you can. While the HT circuit for reading the thermocouples is not terribly accurate, no need to make it worse. Jim