#127

A front i2c port is an awesome idea.

#128

Thanks for the info. What does MSW stand for, by the way?

#129

Michigan Synth Works.

They build a lot of open source modules and hardware for sale. Many get their 16n’s from them.

1 Like
#131

Am I missing something, or is the switch on the back of the Teletype board not in the BOM?

Does anyone have a part no. for it?

hi @desolationjones how did you do the display window?

#132

you don’t need it, but it’s helpful if actively developing firmware. this reset button is not populated on units we ship

1 Like
#133

_DSF2568
_DSF25684896×3264 3.79 MB

I know you didn’t ask me specifically, but I achieved the same thing by carefully scoring and snapping a piece of 2mm plexiglass to size, and then filing down the corners to fit :slight_smile:

I was quite pleased with the result!

3 Likes
#134

That looks great! @tehn you dont happen to have the screen plexi files do you?
Cheers

1 Like
#136

Great thanks for the info, @tehn

Looks really nice @ganders

1 Like
#137

I… really don’t know! Hadn’t even noticed it in there haha. You’d have to ask Raph at MSW. I don’t think he intends on selling these but he would probably clue you in on the window fabrication.

#138

IMG_20200527_232401656
IMG_20200527_2324016561000×1333 524 KB

I finished my Teletype tonight using PCBs I ordered from JLCPCB. I tried out their PCBA service and had almost all of the resistors, capacitors, and diodes populated by JLCPCB. In total the board came with 120 pre-soldered components, which saved me from having to hand solder 250 separate solder joints. I have soldered 0402 components before, and I have to say I’m not very fond of parts that small. Having those components pre-populated made the build reasonably fast and easy.

From what I have gathered at least 3 people (including myself) have ordered PCBs from JLCPCB with different results:

  1. @hi.mo didn’t mention any problems with their service
  2. @forestcaver ordered boards that came back with a short between power and ground
  3. @frankchannel (me) ordered boards that were rejected by JLCPCB’s internal audit

My boards were rejected because the slots in the milling layer intersect with the ground and power planes at several points creating potential shorts. Interestingly, JLCPCB didn’t reject @forestcarver’s submission, and indeed his boards came back with a short. Perhaps I was just lucky with the engineer who got assigned to my boards?

There are quite a few slots on this board: on the USB connector, the potentiometer, and all of the jacks. The slots were created by drawing an outline on the milling layer; however, this may be problematic because Eagle’s DRC ignores this layer [1]:

Unlike the Dimension layer, which can interact with your design rules, the Milling layer does not.

This means that copper pours may go right through a slot, and create a potential short [2]:

When using Slots with a 4 layer PCB, you MUST manually verify internal layers. Eagle’s DRC does not respect any method of making slots, and copper pours or auto-routed traces will short to the slot.

My solution was to remove all of the slots from the PCB and only use normal pads (which respect Eagle’s DRC). JLCPCB accepted my revision and I’m happy to say the boards work.

I’m still puzzled as to why @hi.mo didn’t have any problems with their boards, and why @forestcarver’s boards from pcbway came back fine. Clearly many people haven’t had any problem with the slotted boards — and of course monome has been successfully manufacturing these boards for several years. If anyone has additional thoughts on why this might be I’d be keen to hear them.

For anyone who is interested I will fork monome’s git repository so that I can share my “slotless” revision. I have a few partially populated boards to get rid of…

[1] https://www.autodesk.com/products/eagle/blog/every-layer-explained-autodesk-eagle
[2] https://docs.oshpark.com/design-tools/eagle/cutouts-and-slots

7 Likes
#139

Youre lazy! 0402 are fun to solder !!
Just kidding, i actually dont mind at all :slight_smile:

#140

Hi, does this mean you use a soldering iron, flux and tin solder and prefer this due to be more precise? Worked this for you without desolder copper? I`m curious about the possible methods as I only did through hole projects in the past. Thanks.

#141

Hey! I am about to order all I need to build one of these. However, I can not find the part for the plastic part of the switch (close to the USB) and the spacers/screws for the screen.
Does anyone know the part number?

#142

Spacers/screws are listed on the GitHub page in the readme file. I thought the switch cap was in the BOM? If not it’s in my partial BOM here: https://octopart.com/bom-tool/oMJlcKGp

Note: the screen headers in the original BOM don’t work very well. They are several mm too tall. My partial BOM (linked above) has an alternate low profile header that might work better. My BOM also has the light pipes. There were a few missing resistors in the original BOM too, so you’ll want to make sure you get them…

2 Likes
#143

Apologies if this has been mentioned already, but did anyone find it necessary to remove the plastic part of the male header underneath IC2 (the vreg that poked through the cutout in the board) so it fitted flush against the mainboard?

It doesn’t look like I can get the display low enough without doing that, but I may be missing something.

#144

Many thanks! I will make sure I check to have everything

#145

that happened to me too. I pushed in the regulator before soldering. That was on me second teletype build though, learned for the first

#146

Hi @thopa.

I desoldered the VREG on both my boards, removed the plastic spacer and re-soldered them flat.

I’m confused about the whole flashing the firmware bit, I have to say… Maybe I should read up on Docker.

1 Like
#147

Flashing the firmware is the same as updating it. Plug a USB cable from the teletype to computer and run the dfu programmer…

#148

I’m confused about the dependencies, and how Docker fits in.

I’ve managed to compile the firmware, using the Docker instructions. Am I supposed to use the Docker image to flash the module, though, or install the libavr toolchain and run flash.sh without Docker?