Cara questions

[sduck]

Just got one of these built. First time building and using the whole vagrant thing - I didn't really know what I was doing, but followed instructions, and it works! Haven't the the calibration/reprogram thing, that's for tomorrow. Two questions - that group of 3 bicolor leds - there are two of them. The one on the right side is blinking appropriately, doing both colors, everything looks good. The group on the left is only blinking red - is this normal? Nothing is plugged into it, and I don't really know much about how to use this yet, maybe a newbie issue.

Second question is the jack lights - do they do anything besides just shine and look good? Or are they just always on? I screwed up and soldered them on all backwards, caught my mistake and desoldered them and resoldered them in correctly. But during that process i lost one of them, and pulled a pad on one of the slots, so left that one empty, and now the 3 to the right of it aren't working unless I jumper the cathode pad from the next one over. Just trying to figure out my repair options here.

[sduck]

Ok, I think I've figured out the answer to those 2 questions. Third one: the middle led of the right side group of 3 - the X2 one, is stuck on (red) all the time. I've tried reflowing it, no change. What would cause this? It's associated output is working as expected.

[forestcaver]

If only there was a moderator to move this to the ‘unsuccessful bulds’ thread :-) (x lots)

I havent built a Cara - but have built three marbles (for my own use) - but if the output at the jack is fine, the only thing that drives the led is one of the opamp sections. Iirc they’re tssop with pads the same size as the pins so it’s easy to have dry joints (most likely by far). If the output is off - check the ref_bias at the opamp section that drives the ouput. It’s vaguely possible it needs calibrating but that’s not it in if there’s a stuck led when the output of the jack goes positive and negative by a few volts.

[sduck]

Thanks - I reflowed that corner of the offending opamp, and it works now. Yay! Hey - I notice on your github page about marbles that you add that I should erase flash first - how do I do this? I'm kind of working my through this slowly.

[forestcaver]

Thanks - I reflowed that corner of the offending opamp, and it works now. Yay! Hey - I notice on your github page about marbles that you add that I should erase flash first - how do I do this? I'm kind of working my through this slowly.

IMG_2413.JPG

Cool - goid news! Erasing flash - if you use the mi dev environment, the default upload commands erase it. (You have to explicitly choose not to, or use stlink utility without, iirc, a tick box set)

[sduck]

...and, it's calibrated. And, another problem. I'm using a mantis case as a bench power thing, that i used to testing and calibration - it works fine with that case. When I put the module in my big case it doesn't work - just the leds on the left side light up, everything's unresponsive. Doesn't seem to cause any problems - the thing still works fine if I attach it to the mantis. No magic smoke or anything. No problems with anything else in the big case when it's in there not working - everything else is still working fine. Tried a bunch of different power cords, same result. Weird.

[forestcaver]

I saw your post about the cases’ power and it’s sorted. Just one note - marbles can have similar power on issues to the performer...

[hernangmn]

Hi there! greetings from argentina.

I'm having some issues with a diy cara. i didn´t build it by my self, but since i understood how the module works, i'm starting to believe that it has some problems.

the first doubt i have is about scale selection:
i´m about to think that i am crazy, but sometimes when i hold the voltage range button in order to choose the scale i just get the led blinking in organe color and 6 diferents blinks (one blink, two blinks, three blinks, until 6 blinks) I thought that was the way it represent that function considering there are 6 scales availables...but sometimes i get green, orange and red, each one with one slow and one fast option, like the mutable instruments version does.
is it working wrong or are there 2 functionalities availables holding that button and then i´m missing something?

the other problem is that if the module plays scales i´m not getting something so much "musical", i know that at this point i could be doing something wrong, i´ve just tried it with a behringher dual vco. I also have the possibility to try it out with a erica synth sampler, i could try with a percussion sample that has a noted note or even with some synth wave. If some know how the check the propper functionality of this i will really appreciate the help.

[waves_of_awesome]

I bought a Cara that seems to have all the knobs reversed, ie clockwise is anti-clockwise. Would a simple firmware update fix this?