I currently am using a Gen 3 electronics set from Makerbot on a Mendel frame. I have had no issues with the motherboard and flashing or controlling it, but the extruder controller is another story. At first when I was trying to flash firmware I had no luck, I then purchased a USBTinyISP, made it and try to burn the bootloader over again. It didn't work the first time but when I tried again it finally did, third attempt I believe. I then was able to get the proper firmware on the board and get it to start up. At first I registered temperature and the scrolling command line was having no issues showing me the details. Then after about 2-3 minutes it started jumping and the temp stopped updating. I reset the board and I then had no temp. I have since replace the thermistor as a precaution but am still registering good on the ohm meter. I am using this model :http://www.mouser.com/Search/ProductDetail.aspx?R=B57560G104Fvirtualkey59250000virtualkey871-B57560G104F the curves for this model are in the PDF on page 36, and also a 4.7k Ohm resistor in series because it drops down to about 300 ohms at operating temp. I can verify that there is resistance with everything hooked up, there is voltage across the circuit when it is on, and there is voltage across the capacitor directly above the thermistor connector. I can turn on the fan, since it doesn't have a safety mechanism, I cannot turn on the heat obviously. As far as I can tell everything else is working ok. Here is the thermistor table that I am using and as far as I can tell I have done everything correct….
// r0: 100000
// t0: 25
// r1: 0
// r2: 4700
// beta: 4198
// max adc: 1023
#ifdef USE_THERMISTOR
#define NUMTEMPS 20
short temptable[NUMTEMPS][2] = {
{1, 752},
{54, 242},
{107, 199},
{160, 176},
{213, 160},
{266, 147},
{319, 137},
{372, 128},
{425, 119},
{478, 112},
{531, 105},
{584, 98},
{637, 91},
{690, 84},
{743, 76},
{796, 68},
{849, 59},
{902, 49},
{955, 34},
{1008, 3}
};
So is my Arduino just sucking and not working or does anyone else have any ideas why this one board won't work properly? Capacitor? And yes I have the same temp table uploaded to both the mobo and extruder.
