Today I just found out that typos in your C-Code sometimes can be lethal.
e.g. if you type a 61 instead of a 60 for the maximum number of values in your array,
your µC might just hang and melt down your PEEK heat stopper.
I’ve already ordered a new hot end.
Hopefully it arrives soon.
In the meantime I’ll optimize the way, R2C2-Firmware manages the heating.
Because there are more efficient and stable ways to do so…
Ok. The following information can be taken out of the R2C2 schematics from BitBox:
http://ftp.o2s.ch/RepRap_BitBox_Wolfgang/calculus3.html
With this calibration and connecting the two power resistors into series it now shouldn’t start smoking anymore.
Well. At least as long as you prevent Ari from turning the heat onto 240°C again >_>
In our CCCZH laboratory we are using the R2C2-Electronics from BitBox now.
The hotend is made by Wolfgang from reprap-fab.org.
First run. Uh! Oh! It’s smoking.
We had to drill and poke the PLA out of the PEEK.
What had happened?
Well. Math happened 🙂
http://ftp.o2s.ch/RepRap_BitBox_Wolfgang/calculus2.html
The Bitboxers obviously dimensioned their serial resistor for another thermistor.
Wolfgang is using the B57560G104F in his hotend.
So with a 10kΩ resistor in series the voltage on the ADC will look like that:
While basically it should look like that (with R1=500Ω):
Or in short: Let’s get the soldering iron again >.<
The C-Code will then look like that:
/* {ADC value Extruder0, ADC value HeatedBed0, temperature} */
uint16_t temptable[NUMTEMPS][3] = {
{950, 60, 300},
{1552, 95, 248},
{1891, 119, 226},
{2380, 215, 198},
{2653, 293, 183},
{3006, 447, 163},
{3294, 641, 145},
{3488, 865, 131},
{3765, 1408, 105},
{3901, 1906, 86},
{3999, 2732, 64},
{4053, 3352, 42},
{4077, 3755, 22},
{4089, 4085, 0}
};
In case you’re looking for a powerful stepper driver, take a look into this PDF: http://ftp.o2s.ch/RepRap/drivers_overview.pdf
It’s an overview of driver chips from ST.
I’ve chosen the L6208Q for my new RepRap-Electronics design.
It’s the strongest possible SMD part which still does PWM and stepping logic on it’s own.
If you wanna go SMD and you are looking for an alternative which is not as damn expensive as the L297 in SMD case, I’ll spare you the rest of the 20 awake nights.
It’s the A4989.
Under the following link you can buy one for around 4$ which is half of the price for an L297 in SMD:
http://www.digikey.ch/scripts/DKSearch/dksus.dll?Detail&itemSeq=116726484&uq=634771081247262960
As some of you maybe have learned, the last few weeks I was busy with my examina.
Beyond this, I sometimes relaxed my brain a little bit by tinkering around on my ASUS transformer prime.
As you certainly know, the ASUS transformer prime uses a TEGRA3 with the fuses burned into using an AES 128-Bit crypto engine, which forces one to use only bootloaders encrypted by ASUS.
My solution would have been to chainload U-Boot instead of a linux kernel and then using this U-Boot in order to allow multi boot and easier debugging and DeviceTree-Support and so on.
Unfortunately, this turns out to be quite unpracticable as the following mail dialog has destroyed my dreams of an easy solution:
http://www.mail-archive.com/u-boot@lists.denx.de/msg86389.html
And here the final destroying FAQ which bombs us back to square one:
http://www.denx.de/wiki/view/DULG/CanUBootBeConfiguredSuchThatItCanBeStartedInRAM
Maybe I should send the TF201 to China, ask them to unsolder the TEGRA3 and replace it by another non-fused TEGRA3…
Some black market guys will certainly be that kind and will do this… >.>
| TEGRA2 | Unusable crap |
| TEGRA3 | Awesome stuff |
| OMAPx | Awesome stuff |
Hi folks
Everything works now
Next: Compiling Gentoo with KDE4 🙂
Maybe you think:
“Uh, ah! A tablet. ARM. Compiling Gentoo directly on this device?!
That takes ages!”
Nah. Goes like butter 🙂
4 cores, 2GHz, piece of cake.
That’s progress.
I’ve got the same CPU power in this little sweet net book as I have in my big tower build host in the cellar… >.>
EDIT:
And now you can also walk around naked in front of the TF201’s webcam, because now it’s running a GNU/Linux 😉
Ha!
Debian SID ARMHF with the unstable hardfp drivers from the nVidia-page (works well!) on an ASUS Transformer Prime.
It’s TWM with XTerm you’re seeing here right now.
Next issue: Getting USB working, getting the Synaptics driver working, compiling Gentoo for this device (maybe directly on it? I mean… 4 cores… each 2GHz 😀 )
