#65

Excellent! I think that’s fine then, thankyou :slight_smile: - I guess I’ll need a screen to load presets though!

EDIT: wait - I just checked - some of the LED’s had arrows like you posted, which I think are good. The lower row of LED’s however, had a T shape on them. I matched these up with the T shape on the silkscreen so that the T on the LED and on the silkscreen were the same way around. Is that backwards?

#66

I can check later but i think the mark on the silkscreen is on the top marking the cathode not the anode.

Yes all the leds have the same orientation, and the marking on the pcb indicate the cathode, pretty sure…but gave to open the eagle file.

Do you have eagle?

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Edited I just looked at eagle files, anode (+) is opposite to the silkscreen markings

#68

Hurrrayy! Things look like they work :slight_smile:

Couple of things I’ve noticed though;

  • my keyboard repeats a lot of keys, and
  • TR 4 LED doesn’t turn off if I type TR 4 0

The keyboard is fine on a regular computer. Anyone have any ideas? Do either of these sound like I’ve mucked up the build somewhere? thanks a lot!:slight_smile:

#69

Great :slight_smile:

Keyboard must be not have a usb hub ( i think)

This are the ones monome sales:

There is a post about mechanical keyboards for teletype.

Have you checked if there is signal on the jack associated with the led? Meaning the led might not be working but the signal is there.

I would start there.

If there is signal it could be a led gone bad or a cold solder joint. Check the solders joints around the led resistors.

Hope you get it fixed.

1 Like
#70

Hi all! Can anyone provide a part number for the alpha encoder and the button cap? Also, clarifying what someone ask not long ago, are R43 and 44 39 ohm resistors?

Thanks for your help!

#71

I can confirm R43 & R44 are indeed 39 ohm resistors, the part number for the pushbutton cap is EG1882-ND with digikey, or manufacturer number 1RBLK. For the potentiometer I just got the B10K alpha one from thonk (not an encoder!)

@thopa - the issue isn’t that the LED doesn’t work, it’s that it never turns off! :rofl: any idea what might cause that? I think you’re right about the keyboard though - the one I’m using is a backlit mechanical ducky keyboard… I need to find a normal one from somewhere.

#72

How’re people finding the 0402 passives to solder?

#73

With a magnifying glass and something to precisely place solder paste & the parts, I think it’s not that much harder than 0603. The ICs were a bit of a PITA though, especially that big CPU IC in the middle :joy:

#74

Ah, so you used the solder paste method, then.

I’ve always used the drag-solder method for fine-pitch ICs. Has usually worked for me, though on one occasion I did manage to kill an STM32x MCU when an almost invisibly tiny piece of solder braid broke off and shorted some pins.

#75

As @forestcaver suggested on his great blog :slight_smile:

http://www.zen159313.zen.co.uk/guitar/modular/02_diy_modules.htm

If you are going to be doing quite a bit of smd, get a stereo microscope.

Took me a few days to get used to it, and burned myself with the iron a few times, but it will save you lots of headaches and i really enjoy that kind of view a microscope gives! My kids love looking into it too :slight_smile:

Debugging is also (mostly) easier if its because of some soldering mistake.

Best purchase for a long time!

2 Likes
#76

Yeah - an optical stereo microscope was the best bit of kit for smt soldering… Before that, I used a magnifying visor (even on 0402) - most builds would have a soldering error (I’d pretty much expect it). After the microscope, I cant recall making a soldering error… it was genuinely that big a change - you see just how crap your soldering really was previously! If you think in terms of time, it has paid for itself many, many times over - in terms of more fun it’s incalculable…

1 Like
#77

With respect to the TR 4 LED sticking on, could it be related to my having got solder in the via?

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Edit; I measured all the triggers outputs while they were high - TR 1,2 & 3 were about 9.8V but TR 4 is stuck on 10.8V :’( definitely a short somewhere

#78

I doubt it 20 characters.

#79

Hiya, yes i don’t think it’s that either but not 100 % sure will have to check the files.

You are going to have to track down what feeds that led as it’s obviously shorted.

I’ll catch up later :slight_smile:

1 Like
#80

I FIXED IT!!! :heart_eyes: R47 was only properly joined on on 1 side! 🤦
@thopa & @forestcaver thankyou for your input, and I see what you mean about a binocular microscope haha! I would have spotted that a lot sooner I think

4 Likes
#81

Go enjoy it! Well spotted :slight_smile:

#82

IMG_20200321_123649
IMG_20200321_1236493000×4000 4.47 MB

Thanks guys & thanks @tehn for designing and open sourcing this! :heart_eyes:

17 Likes
#83

Having a slightly odd issue - sometimes the screen misbehaves? :confused: I made certain I cut the pins on top of the display shorter, and even put some insulating tape on the other side of the panel. Sometimes the screen doesn’t turn on at all, sometimes it displays seemingly random pixels (while the rest of the teletype works perfectly fine - can still send triggers and whatnot), and the rest of the time it’s 100% fine.

Does this sound like a dodgy display? Dodgy power supply? Any/all of the above? :stuck_out_tongue: Cheers for any input!

#84

reheat your solders: everything has to do with connection. (welcome to hand-building. while developing the norns i was in a constant battle of doubting the code vs. the soldering. luckily, you know the code is correct.)

10 Likes
#85

…I hadn’t quite cut one leg of the display down enough (I effectively just sharpened it…) and it had poked through my electrical tape :sweat_smile: All good now!