-=( GitHub ,Marlin and madness )=-

For those who know me somewhat, i have struggled with Github and the quite frankly "weird" way it works,  i have tried to follow quite a few of the "idiots guides to Github" to no avail mostly because they are either outdated or just assume some miss-understanding around the inner un-published workings of Github. i have managed so far after many months to put the modification i made with the author help into GitHub and submitted it for merging, but this was done on GitHub through the web based editor , i have yet to master the art of uploading a damn file.....

in the interim since i'm now email links to dropbox for the modified copy of marlin i have to people who want them and pasting links on Facebook, i'm going to link it here and in the reprap.org wiki,

[click here] to download a copy out of my dropbox

-=( Powersupplies and Pwm )=-

One of my many problems with power supplies have been solved by the location of a decent supplier of bulk 180watt power bricks:

these things are advertised with overload protection and short circuit protection, and actually have it in there.

the downside to these power supplies is that it is relatively easy to  trigger the overload protection or hiccup mode as these powers supplies are designed to plug into very specific piece of equipment and usually there are capacitors built into the device.

so Marlins style of low frequency (7hz) pwm may as well be bang bang in this particular application, the solution is to make it do genuine pwm using the avr's pwm module.

after talking to Evdz on #reprap irc it turns out that it's rather simple to make use of the hardware pwm, the reason it's done with the bangbang style in software is because of compatability across the range of boards,

so inside temperature.cpp you will find this line (line number 1075):

if(soft_pwm_b > 0) WRITE(HEATER_BED_PIN,1); else WRITE(HEATER_BED_PIN,0);

 and replace it with this:

if(soft_pwm_b > 0) analogWrite(HEATER_BED_PIN,soft_pwm_b); else analogWrite(HEATER_BED_PIN,0);

what you should see now is pwm frequency around 500hz on your bed heater output, this will only work provided the output is pwm capable which for me it is on the rumba board , this could also be done on the other heateroutputs and on the fans as well if you really wanted to but i haven't quite gotten that far yet

-=( up close and personal )=-

I have recently acquired for myself a reversing ring for the Nikon D3100, this little $3 contraption allows me to attach a lens on my DSLR the wrong way around and allow me to photograph a miniature world otherwise not possible using the lens in the traditional manner,

if you do this, do not do it with the newer plastic type lenses as there are only two threads supporting the weight of the lens , get an older lens to do this with preferably on of the many aluminium built ones that are available, it doesn't even really need to be the same brand as the camera...