Trouble with Temperatures

I recently replaced my extruder board (gen 3 electronics), and while the new board appears to works fine, the temperature range now varies. It heats up to 200-203 and then cools to ~160 and then oscillates in this range. I'm guessing this is controlled in the software (Arduino-21) somewhere. Could someone tell me where.

Thanks

check your firmware and what thermistor table you have enabled in the config vs. the thermistor you are using.

thanks for responding Redbeard. I'll look into this. It just seems odd that with the last extruder board the temps ranges seemed to work fine. Another thing is the temperature does appear to work....just goes a bit high and then too low, but I think the thermistor is working

Edited 1 time(s). Last edit at 10/17/2011 06:28PM by HereIgoAgain.

Today I went thru and verified my thermistor, used the python script and generated new values for the thermistor and recompiled the code. Unfortunately with the same results. It seems the resistor when set to 190 will heat to ~203 and then cool to about ~165 repeatedly. does someone know where in the code I can look to set the parameters for how long to heat and when to stop ?

Hmm.

I would need to know more about your hot end design, and where the heater and thermistor are mounted. Maybe if you can post a picture...

It might be useful to post your thermistor table. You might not have enough points in the 190-270 range.

Just checking, but you are uploading the firmware to the extruder controller, and not the motherboard, yes?

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-Nudel
Blog with RepRap Comic

Hi all and thanks for responding. I've included the table I'm using followed (commented out) by the original values.


// ./createTemperatureLookup.py --r0=100000 --t0=25 --r1=0 --r2=5000 --beta=4400 --max-adc=1023
// r0: 100000
// t0: 25
// r1: 0
// r2: 5000
// beta: 4400
// max adc: 1023
#define NUMTEMPS 20
short temptable[NUMTEMPS][2] = {
{1, 637},
{54, 222},
{107, 184},
{160, 163},
{213, 148},
{266, 137},
{319, 127},
{372, 119},
{425, 112},
{478, 105},
{531, 98},
{584, 92},
{637, 85},
{690, 79},
{743, 72},
{796, 64},
{849, 56},
{902, 46},
{955, 32},
{1008, 3}
};


//to
// RS thermistor 528-8592; EPCOS NTC G540
// ./createTemperatureLookup.py --r0=100000 --t0=25 --r1=0 --r2=4700 --beta=4036 --max-adc=1023
// r0: 100000
// t0: 25
// r1: 0
// r2: 4700
// beta: 4036
// max adc: 1023
//#define NUMTEMPS 20
//short temptable[NUMTEMPS][2] = {
// {1, 864},
// {54, 258},
// {107, 211},
// {160, 185},
// {213, 168},
// {266, 154},
// {319, 143},
// {372, 133},
// {425, 125},
// {478, 116},
// {531, 109},
// {584, 101},
// {637, 94},
// {690, 87},
// {743, 79},
// {796, 70},
// {849, 61},
// {902, 50},
// {955, 34},
// {1008, 2}
//};
not much difference, and they both work the same ie. oscillate between ~165-202. I've included a picture of my hot end. Note that once this all works I will insulate better and trim the wires. This arrangement was working fine with my last extruder board. The firmware is loaded into the extruder board as oddly enough, I must use anduino-22 for the motherboard and arduino-21 for the extruder (this I learned in another post from this forum). I have now run the software thru 3 or 4 iterations with the same result. whatever it is doing it is doing consistantly just wish I could close the range. Any ideas ??

Is the thermistor inside a hole in the heating block or is it just taped on with kapton tape? If it's not in the hole, it won't measure accurately and it can result in oscillation.

The table should still work assuming that it's the correct one for your thermistor, but you should generate more points in the upper range to increase the accuracy.

Hey again,
I took what you mentioned to heart and while I couldn't place the thermistor in the material (it isn't round), I did heavily insulate the heater block thinking maybe it was cooling and heating faster than it could respond to. I also changed the number of points from 20 to 30. The resulting changed the outcome to the range 161-233. I let it run for about 10 minutes with about the same results ~161-217. With my last extruder board, temperatures were never an issue. Even uninsulated and kaptoned to the aluminum block the temperatures would range between 185-205 or close. It is when I replace the board that these wide ranges began. That would indicate to me that the change was the result of the board since the software didn't change. that seems odd to me that different boards could have such differences but ok. My thinking is that if I could manipulate where the ranges are controlled ie. where and what in the software turns on the heat and what turns it off , I could tweak these values and make it coorespond to my new extruder board. Perhaps I am missing the boat here somewhere. I do apprecriate all the help.

What firmware are you using and how is it controlling the temperature: bang-bang or PID?

Perhaps might be worthwhile to check the 5V supply rail too. especially if you are using a power supply input >15V.
The ntc adc input is scaled to the 5V rail so any instability here will affect the temp reading.
One possible cause is regulator overheating.
If the 5V regulator starts to overheat, it will cause the regulator overtemp protection to activate, causing the output voltage to slowly oscillate up and down and in turn the temp reading.

Electrical noise on the thermistor wires can cause oscillations also. Correct?

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wow, no lack of ideas here. My firmware for the extruder is anduino 0021. I believe PID is controlling temperature as bang bang is commented out. If I can figure out whats actually going on in the temperature software I think this might help (at least it'll make me smarter). Is is possible to do a run thru of how temperature is delt with in the software. My c skills I think still work (been awhile) but it's hard to get a feel for this software as of yet. Is there an easy way to add print lines to echo out what's happening ? Stanley could you explain how to check the 5V supply rail ?? not sure about that. Is there someway to verify/check the regulator. The thermistor wires are pretty thin. This might be something easy to check out. and once again thanks everyone...what an adventure

Edited 1 time(s). Last edit at 10/23/2011 07:46PM by HereIgoAgain.

I think, according to Nophead, bang-bang works well enough for the resistor-in-block hotend. I recommend setting the firmware for bang-bang control instead of PID.

I also suggest twisting thepair of wires connecting the thermistor to the EC together to reduce noise. You should also do the same to the wires going to the heating resistors to reduce inductance and also cut the amount of noise that it generates when it switches on and of.

Have you also checked to see if you get the correct reading from your thermistor at room temperature and then at a higher temperature? Maybe you can wrap it with plastic and dip it into boiling water.

BTW, the Arduino is the development environment that is used to write or modify and upload the firmware to your MB or EC. You're probably using the reprap host firmware since this is Gen 3. What version is it?

BTW, did you connect your MB and EC grounds and 12V together? The standard wiring doesn't have ground connecting the MB and EC. I think you might need to solder a separate ground wire between them. There should be instruction in the wiki or in this forum.

in regards to the 5V supply.
The ADC input is scaled directly from the 5V, but the ntc although scaled form the 5V supply, it is also filtered before it is applied to the ADC input.
Also since ntc resitance changes with temperature so does filter affect.
So any ripply/oscilation on the 5V supply could theoretically cause the same effect you are seeing.

Since this is a purchased board I assume the regulator input capacitor is connected..
Only other way a regulator can oscillate is if it goes into current or thermal limit.
More likely it is thermal limit
Easy way to check this without a scope is to simply blow on the regulator and see if the output temp reading stabilizes.

Pick up on the ntc connect might well be the cause. But I don't undertstand why it is only at higher temperature. The ntc impedence at 200C(2K) is much lower than at 25C(100K). So I would have thought that it would be more likely to see the pickup problem at room temperature than at 200C.
Hence 5V supply suggestion

Tried to remove PID but without much success. There are a lot of references in the software. Might be easier trying to figure out the PID. I did twist the wires on the thermistor and plan to use twisted wire for the resistor. Hardware is Gen 3 ver1.2 MB and ver 2.2 extruder board. and yes the mother board connects to the extruder thru a pins D9D10 on extruder and SDA SCL on MB. Thermistor looks good at room temp and reads well all the way up. The only real problem is the range of heating and cooling. Seems my last extruder would go 185-195 or in that range. No matter what I do here, it goes over 200 and down to about 165. I played today changing the target temperature in the software but it seemed to make no difference. still 165-200. I'm going to try tapping on the regulator to see if that does anything tonite.

Tried tapping the regulator but not much...here is a listing of the values up to t199 then back down. Maybe better look for yet another extruder board. Brnrd do you have any experience with the software ??

comms: Response: ok T:186 B:120 [166.437s/31ms]
comms: G-code: N129 M105 *13 dequeued and sent [167.937s/1500ms]
comms: Response: ok T:188 B:121 [167.984s/47ms]
comms: G-code: N130 M105 *5 dequeued and sent [167.984s/0ms]
comms: Response: ok T:188 B:121 [168.031s/47ms]
comms: G-code: N131 M105 *4 dequeued and sent [169.531s/1500ms]
comms: Response: ok T:190 B:122 [169.562s/31ms]
comms: G-code: N132 M105 *7 dequeued and sent [171.062s/1500ms]
comms: Response: ok T:191 B:122 [171.093s/31ms]
comms: G-code: N133 M105 *6 dequeued and sent [172.593s/1500ms]
comms: Response: ok T:192 B:123 [172.640s/47ms]
comms: G-code: N134 M105 *1 dequeued and sent [172.640s/0ms]
comms: Response: ok T:192 B:123 [172.687s/47ms]
comms: G-code: N135 M105 *0 dequeued and sent [174.187s/1500ms]
comms: Response: ok T:193 B:123 [174.218s/31ms]
comms: G-code: N136 M105 *3 dequeued and sent [175.718s/1500ms]
comms: Response: ok T:194 B:125 [175.750s/32ms]
comms: G-code: N137 M105 *2 dequeued and sent [177.250s/1500ms]
comms: Response: ok T:195 B:126 [177.281s/31ms]
comms: G-code: N138 M105 *13 dequeued and sent [177.281s/0ms]
comms: Response: ok T:195 B:126 [177.328s/47ms]
comms: G-code: N139 M105 *12 dequeued and sent [178.828s/1500ms]
comms: Response: ok T:196 B:126 [178.859s/31ms]
comms: G-code: N140 M105 *2 dequeued and sent [180.359s/1500ms]
comms: Response: ok T:197 B:127 [180.390s/31ms]
comms: G-code: N141 M105 *3 dequeued and sent [181.890s/1500ms]
comms: Response: ok T:197 B:128 [181.921s/31ms]
comms: G-code: N142 M105 *0 dequeued and sent [181.921s/0ms]
comms: Response: ok T:197 B:128 [181.953s/32ms]
comms: G-code: N143 M105 *1 dequeued and sent [183.453s/1500ms]
comms: Response: ok T:198 B:128 [183.500s/47ms]
comms: G-code: N144 M105 *6 dequeued and sent [185.000s/1500ms]
comms: Response: ok T:199 B:128 [185.031s/31ms] <----------------------------------t199
comms: G-code: N145 M105 *7 dequeued and sent [186.531s/1500ms]
comms: Response: ok T:199 B:128 [186.562s/31ms]
comms: G-code: N146 M105 *4 dequeued and sent [186.562s/0ms]
comms: Response: ok T:199 B:128 [186.593s/31ms]
comms: G-code: N147 M105 *5 dequeued and sent [188.093s/1500ms]
comms: Response: ok T:199 B:129 [188.140s/47ms]
comms: G-code: N148 M105 *10 dequeued and sent [189.640s/1500ms]
comms: Response: ok T:199 B:129 [189.671s/31ms]
comms: G-code: N149 M105 *11 dequeued and sent [191.171s/1500ms]
comms: Response: ok T:199 B:129 [191.203s/32ms]
comms: G-code: N150 M105 *3 dequeued and sent [191.203s/0ms]
comms: Response: ok T:199 B:129 [191.234s/31ms]
comms: G-code: N151 M105 *2 dequeued and sent [192.734s/1500ms]
comms: Response: ok T:199 B:129 [192.781s/47ms]
comms: G-code: N152 M105 *1 dequeued and sent [194.281s/1500ms]
comms: Response: ok T:198 B:128 [194.312s/31ms]
comms: G-code: N153 M105 *0 dequeued and sent [195.812s/1500ms]
comms: Response: ok T:198 B:128 [195.843s/31ms]
comms: G-code: N154 M105 *7 dequeued and sent [195.843s/0ms]
comms: Response: ok T:198 B:128 [195.875s/32ms]
comms: G-code: N155 M105 *6 dequeued and sent [197.375s/1500ms]
comms: Response: ok T:198 B:128 [197.406s/31ms]
comms: G-code: N156 M105 *5 dequeued and sent [198.906s/1500ms]
comms: Response: ok T:197 B:128 [198.937s/31ms]
comms: G-code: N157 M105 *4 dequeued and sent [200.437s/1500ms]
comms: Response: ok T:197 B:128 [200.468s/31ms]
comms: G-code: N158 M105 *11 dequeued and sent [200.468s/0ms]
comms: Response: ok T:197 B:128 [200.500s/32ms]
comms: G-code: N159 M105 *10 dequeued and sent [202.000s/1500ms]
comms: Response: ok T:197 B:127 [202.031s/31ms]
comms: G-code: N160 M105 *0 dequeued and sent [203.531s/1500ms]
comms: Response: ok T:196 B:127 [203.578s/47ms]
comms: G-code: N161 M105 *1 dequeued and sent [205.078s/1500ms]
comms: Response: ok T:196 B:126 [205.109s/31ms]
comms: G-code: N162 M105 *2 dequeued and sent [205.109s/0ms]
comms: Response: ok T:196 B:126 [205.140s/31ms]
comms: G-code: N163 M105 *3 dequeued and sent [206.640s/1500ms]
comms: Response: ok T:195 B:126 [206.671s/31ms]
comms: G-code: N164 M105 *4 dequeued and sent [208.171s/1500ms]
comms: Response: ok T:194 B:125 [208.218s/47ms]
comms: G-code: N165 M105 *5 dequeued and sent [209.718s/1500ms]
comms: Response: ok T:194 B:125 [209.750s/32ms]
comms: G-code: N166 M105 *6 dequeued and sent [209.750s/0ms]
comms: Response: ok T:194 B:125 [209.781s/31ms]
comms: G-code: N167 M105 *7 dequeued and sent [211.281s/1500ms]
comms: Response: ok T:193 B:123 [211.312s/31ms]
comms: G-code: N168 M105 *8 dequeued and sent [212.812s/1500ms]
comms: Response: ok T:193 B:123 [212.843s/31ms]
comms: G-code: N169 M105 *9 dequeued and sent [214.343s/1500ms]
comms: Response: ok T:192 B:123 [214.390s/47ms]
comms: G-code: N170 M105 *1 dequeued and sent [214.390s/0ms]
comms: Response: ok T:192 B:123 [214.421s/31ms]
comms: G-code: N171 M105 *0 dequeued and sent [215.921s/1500ms]
comms: Response: ok T:191 B:123 [215.953s/32ms]
comms: G-code: N172 M105 *3 dequeued and sent [217.453s/1500ms]
comms: Response: ok T:190 B:122 [217.484s/31ms]
comms: G-code: N173 M105 *2 dequeued and sent [218.984s/1500ms]
comms: Response: ok T:189 B:122 [219.031s/47ms]
comms: G-code: N174 M105 *5 dequeued and sent [219.031s/0ms]
comms: Response: ok T:189 B:121 [219.078s/47ms]
comms: G-code: N175 M105 *4 dequeued and sent [220.578s/1500ms]
comms: Response: ok T:188 B:121 [220.609s/31ms]
comms: G-code: N176 M105 *7 dequeued and sent [222.109s/1500ms]
comms: Response: ok T:187 B:120 [222.140s/31ms]
comms: G-code: N177 M105 *6 dequeued and sent [223.640s/1500ms]
comms: Response: ok T:185 B:120 [223.687s/47ms]
comms: G-code: N178 M105 *9 dequeued and sent [223.687s/0ms]
comms: Response: ok T:185 B:120 [223.734s/47ms]
comms: G-code: N179 M105 *8 dequeued and sent [225.234s/1500ms]
comms: Response: ok T:185 B:119 [225.265s/31ms]
comms: G-code: N180 M105 *14 dequeued and sent [226.765s/1500ms]
comms: Response: ok T:184 B:119 [226.796s/31ms]
comms: G-code: N181 M105 *15 dequeued and sent [228.296s/1500ms]
comms: Response: ok T:183 B:118 [228.343s/47ms]
comms: G-code: N182 M105 *12 dequeued and sent [228.343s/0ms]
comms: Response: ok T:183 B:118 [228.390s/47ms]
comms: G-code: N183 M105 *13 dequeued and sent [229.890s/1500ms]
comms: Response: ok T:182 B:117 [229.921s/31ms]
comms: G-code: N184 M105 *10 dequeued and sent [231.421s/1500ms]
comms: Response: ok T:181 B:116 [231.453s/32ms]
comms: G-code: N185 M105 *11 dequeued and sent [232.953s/1500ms]
comms: Response: ok T:180 B:116 [232.984s/31ms]
comms: G-code: N186 M105 *8 dequeued and sent [232.984s/0ms]
comms: Response: ok T:180 B:116 [233.031s/47ms]
comms: G-code: N187 M105 *9 dequeued and sent [234.531s/1500ms]
comms: Response: ok T:179 B:115 [234.562s/31ms]
comms: G-code: N188 M105 *6 dequeued and sent [236.062s/1500ms]
comms: Response: ok T:178 B:114 [236.093s/31ms]
comms: G-code: N189 M105 *7 dequeued and sent [237.593s/1500ms]
comms: Response: ok T:177 B:113 [237.625s/32ms]
comms: G-code: N190 M105 *15 dequeued and sent [237.625s/0ms]
comms: Response: ok T:177 B:113 [237.656s/31ms]
comms: G-code: N191 M105 *14 dequeued and sent [239.156s/1500ms]
comms: Response: ok T:176 B:112 [239.203s/47ms]
comms: G-code: N192 M105 *13 dequeued and sent [240.703s/1500ms]
comms: Response: ok T:175 B:111 [240.734s/31ms]
comms: G-code: N193 M105 *12 dequeued and sent [242.234s/1500ms]
comms: Response: ok T:173 B:111 [242.265s/31ms]
comms: G-code: N194 M105 *11 dequeued and sent [242.265s/0ms]
comms: Response: ok T:173 B:111 [242.296s/31ms]
comms: G-code: N195 M105 *10 dequeued and sent [243.796s/1500ms]
comms: Response: ok T:173 B:110 [243.843s/47ms]
comms: G-code: N196 M105 *9 dequeued and sent [245.343s/1500ms]
comms: Response: ok T:171 B:109 [245.375s/32ms]
comms: G-code: N197 M105 *8 dequeued and sent [246.875s/1500ms]
comms: Response: ok T:170 B:108 [246.906s/31ms]
comms: G-code: N198 M105 *7 dequeued and sent [246.906s/0ms]
comms: Response: ok T:170 B:108 [246.937s/31ms]
comms: G-code: N199 M105 *6 dequeued and sent [248.437s/1500ms]
comms: Response: ok T:169 B:108 [248.484s/47ms]
comms: G-code: N200 M105 *5 dequeued and sent [249.984s/1500ms]
comms: Response: ok T:169 B:107 [250.015s/31ms]
comms: G-code: N201 M105 *4 dequeued and sent [251.515s/1500ms]
comms: Response: ok T:168 B:106 [251.546s/31ms]
comms: G-code: N202 M105 *7 dequeued and sent [251.546s/0ms]
comms: Response: ok T:168 B:106 [251.578s/32ms]
comms: G-code: N203 M105 *6 dequeued and sent [253.078s/1500ms]
comms: Response: ok T:167 B:105 [253.109s/31ms]
comms: G-code: N204 M105 *1 dequeued and sent [254.609s/1500ms]
comms: Response: ok T:167 B:105 [254.656s/47ms]
comms: G-code: N205 M105 *0 dequeued and sent [256.156s/1500ms]
comms: Response: ok T:167 B:105 [256.187s/31ms]
comms: G-code: N206 M105 *3 dequeued and sent [256.187s/0ms]
comms: Response: ok T:167 B:105 [256.218s/31ms]
comms: G-code: N207 M105 *2 dequeued and sent [257.718s/1500ms]
comms: Response: ok T:166 B:104 [257.750s/32ms]
comms: G-code: N208 M105 *13 dequeued and sent [259.250s/1500ms]
comms: Response: ok T:166 B:104 [259.296s/46ms]
comms: G-code: N209 M105 *12 dequeued and sent [260.796s/1500ms]
comms: Response: ok T:166 B:104 [260.828s/32ms]
comms: G-code: N210 M105 *4 dequeued and sent [260.828s/0ms]
comms: Response: ok T:166 B:104 [260.859s/31ms]
comms: G-code: N211 M105 *5 dequeued and sent [262.359s/1500ms]
comms: Response: ok T:166 B:104 [262.390s/31ms]
comms: G-code: N212 M105 *6 dequeued and sent [263.890s/1500ms]
comms: Response: ok T:166 B:103 [263.937s/47ms]
comms: G-code: N213 M105 *7 dequeued and sent [265.437s/1500ms]
comms: Response: ok T:166 B:103 [265.468s/31ms]
comms: G-code: N214 M105 *0 dequeued and sent [265.468s/0ms]
comms: Response: ok T:166 B:103 [265.500s/32ms]
comms: G-code: N215 M105 *1 dequeued and sent [267.000s/1500ms]
comms: Response: ok T:166 B:104 [267.031s/31ms]
comms: G-code: N216 M105 *2 dequeued and sent [268.531s/1500ms]
comms: Response: ok T:166 B:104 [268.562s/31ms]
comms: G-code: N217 M105 *3 dequeued and sent [270.062s/1500ms]
comms: Response: ok T:166 B:104 [270.109s/47ms]
comms: G-code: N218 M105 *12 dequeued and sent [270.109s/0ms]
comms: Response: ok T:166 B:104 [270.156s/47ms]
comms: G-code: N219 M105 *13 dequeued and sent [271.656s/1500ms]
comms: Response: ok T:167 B:105 [271.687s/31ms]
comms: G-code: N220 M105 *7 dequeued and sent [273.187s/1500ms]
comms: Response: ok T:167 B:105 [273.218s/31ms]
comms: G-code: N221 M105 *6 dequeued and sent [274.718s/1500ms]
comms: Response: ok T:168 B:106 [274.765s/47ms]
comms: G-code: N222 M105 *5 dequeued and sent [274.765s/0ms]
comms: Response: ok T:168 B:106 [274.812s/47ms]
comms: G-code: N223 M105 *4 dequeued and sent [276.312s/1500ms]
comms: Response: ok T:168 B:107 [276.343s/31ms]
comms: G-code: N224 M105 *3 dequeued and sent [277.843s/1500ms]
comms: Response: ok T:169 B:107 [277.875s/32ms]
comms: G-code: N225 M105 *2 dequeued and sent [279.375s/1500ms]
comms: Response: ok T:170 B:108 [279.421s/46ms]
comms: G-code: N226 M105 *1 dequeued and sent [279.421s/0ms]
comms: Response: ok T:170 B:108 [279.468s/47ms]

Ok. I just checked the firmware that I was using and it looks like I added the bang-bang code to it. I thought it was an option.

Before you abandon PID, check your PID constants in the extruder.h file. I just looked at the latest version in github and it has the following:


// PID definitions

#define TEMP_PID_INTEGRAL_DRIVE_MAX 110
#define TEMP_PID_PGAIN 5.0
#define TEMP_PID_IGAIN 0.1
#define TEMP_PID_DGAIN 100.0

Is yours the same? If not, try changing to these values.

If that doesn't work, try this Extruder.zip firmware which I was using before I switched to RAMPS. It's set to use bang-bang control on the extruder and the heated bed. You should be able to use it after replacing temperature.h with your own. If not, you can paste your table(s) into my temperature.h.

Edited 1 time(s). Last edit at 10/24/2011 08:24PM by brnrd.

Hi again Brnrd

I was just about to check with you again and thought I would check this thread first. I am not sure what started is thread but my problem was that my Extruder temperature would come up to a point and then kick out. For example starting cold it was 18 setting it to PLA 185 degrees it would come up to 86 and stop. If I tried again by setting it to 0 and then resetting it to PLA 185 it might come up to 134 but that was it. I checked the voltage going to the element and it's dropped to 0 volts dc. I put your PID values in and it work great.

Thanks again

Hey Brnrd,
I do have the same PID values so I am exploring the software you sent. On the first go around, I copied my temps into your temp.h program but when I ran it it does heat but the temperature doesn't change. It's getting late tonite and I will try it again tomorrow. thanks for you help

Yes same thing today. When started, the current temperature reads -8, no matter what my temp.h file reads. The program run ie. the resistor will heat, but the temperature is not monitored.

So another question, If I should decide to retire my gen 3 electronics, where is your recommendation for new electronics. It looks like there is a gen 7. And does this contain everything on one board (no need for stepper motor boards or extruder ?

thanks....it's good to have a plan B

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Barry Law
...I put your PID values in and it work great.

Thanks again

You're welcome. I'm glad that fixed your problem. Those values are the default firmware settings.

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HereIgoAgain
Yes same thing today. When started, the current temperature reads -8, no matter what my temp.h file reads. The program run ie. the resistor will heat, but the temperature is not monitored.

Is the the heater constantly on or is it being regulated: turning on and off. I wonder if it's just a problem with reading the temperature. It might be miscommunication between the MB and EC firmware. What version firmware do you have on the motherboard?

Oops! The version that I posted has the extruder stepper motor codes commented out since I had already switched to using a Pololu controller by that time. It should still control the extruder and bed temperature. If the bang-bang temperature control works, let me know and I'll uncomment those sections. I'll also take a look at the current firmware in the 5D repository and see if bang-bang is an option.

In the latest 5D firmware in sourceforge, the temperature control for Gen 3 (separate EC) is still PID while for internal extruder, it's bang-bang. But it's easy enough to add bang-bang for Gen 3 if needed.

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HereIgoAgain
So another question, If I should decide to retire my gen 3 electronics, where is your recommendation for new electronics. It looks like there is a gen 7. And does this contain everything on one board (no need for stepper motor boards or extruder ?

thanks....it's good to have a plan B

I'm sure you'll get different answer from others. But I chose RAMPS since it seems to be stable and I like the modular design. Separate microcontroller and plug-in stepper controllers. I think the Sanguinololu is also a good choice. iI's more compact and cheaper since it's a single board design, but the microcontroller and stepper controllers are also plug-in replaceable.

Edited 2 time(s). Last edit at 10/29/2011 11:08AM by brnrd.

not sure if the heater stays on or not since the temp indicator doesn't work. I'll play with it again today and see what happens

Spent time returning software back to the original with about the same results. Plan to make one attempt using the software you sent to see if it was a loose wire or something that kept the thermistor from registering (moving from -8). In the wiki, [reprap.org] it suggests gen 6,7, RAMPS or Sang boards, so your comments regarding RAMPS and Sanguinololu seems like a good suggestion. Not quit sure how Ramps operate and have looked at Sanguinololu. Since I have now spent about a year getting a first print from my machine , I guess I'm not in a hurry and think I will go ahead and try to build this board, and perhaps better understand how they work.

HereIgoAgain Wrote:
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> not sure if the heater stays on or not since the
> temp indicator doesn't work. I'll play with it
> again today and see what happens

You can measure the voltage across the resistor to see that you're getting 12 V. Once it reaches the set temperature, you should see the voltage alternate between 12V and 0 as it regulates the temperature.

Today I am encouraged. I retightened and checked each and every wire. I also pushed on all chips and then went back to the files brnrd sent. Here are my results:
temp set : 190 range 180-190, 181-191, 182-190
temp set : 200 range 194-200, 194-200
temp set: 195 range 187-195, 188-195

each time led for resistor (temp on) went out at the upper limit

This looks good. Don't know what will be next ...but I'm sure the forum will be hearing from me again. Thanks so much for your help brnrd and everyone else who responded.

Remember that the version of firmware that I posted has the stepper motor controlled disabled (commented out). You might want to try loading the Extruder firmware that came with the latest 5D release. It's set for PID. But if it doesn't regulate your temperature well, we can always add bang-bang to it. Just let me know and I'll do it for you.