#1489

It may be hard to see, but the LED symbol has a flat side that corresponds to the flat side of your LED.

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It is the side that is facing away from the connected resistor. It represents where the cathode (short leg) should go.

Here are the LEDs in the schematic:

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Hope this helps. :slight_smile:

2 Likes
#1490

Do you have a link to those helper boards? I’ve scoured github for the Gerbers or links to Oshpark. I have a telexo and a teensy 3.6, but am struggling to find the rest of what’s needed to complete the upgrade.

Edit: spoke too soon. Found it a few comments up.

#1491

Got some questions about the i2c ports on these expanders. There are two sets of three pins, do one represent in and one represent out? Or, if I have a daisy chain ribbon that attaches all of my modules can I just connect one plug to three pins and move on to the next module?

Basically, I am wondering if three pins would be in, three pins would be to connect to the next module (meaning contact to all six pins), or if just making contact to three pins in all I need?

#1492

hop down to the “how do i connect everything section” of this wonderful guide to all things i2c:

5 Likes
#1493

Hello, so, I have built my TXo+ and was attempting to give it a spin. I have noticed some issues and was hoping someone could help me pinpoint whats going on.

Summary

If I just want to test the trigger ports, I type TO.TR.TOG 1 1 and I get a quick flash. The trigger won’t hold on, it just quickly flashes. This happens with 2 of the 4 ports (the other two I need to obviously fix altogether). Would anybody have some tips on where on the module I should look to fix this issue?

As well, if I . attempt to toggle an input a few times, it locks up my teletype…

Further explorations also show that when I choose, say, TO.TR 4 1, it will just send continuous pulses. And when I try to stop them, it will lock up the teletype as well.

Okay, I have found the issue and fixing it without a new board is going to be a real challenge. Bummer.

So, having done some real sitting down and looking at the board, I deduced that my DAC was upside down. With some fiddling, I got that sucker properly turned around and seated. The TO.TR 1 1 still has an issue where the pulse shorts out, but I see that there is a bit of a short with the power flowing through there. That should be a relatively easy fix with some flux.

After the whole adventure, I have a working TXi and TXo+, hopefully I can answer some questions people might have if their builds get wonky, since, like all of my DIY projects, have taken any number of detours

2 Likes
#1494

This is a separate question, but is there a good breakdown or resource covering the use of the TXo as a synth with the four voices?

2 Likes
#1495

I’m planning to cover that in the next Teletype Talk video. I’m hoping I might get that out this weekend. It’s actually that that brings me to this thread,. I was trying something I haven’t before as an experiment and wondered if anyone can shed some light.

I was using TI.IN.N to grab a V/Oct pitch sequence. It seems like it takes TXi a little while to latch onto a changing voltage. If I trigger a script like this one from the gate signal of a pitch sequence with the V/Oct component fed into TI.IN 1:

1:
X TI.IN.N 1

X will almost never have the correct value. It will be something between what it was and what it’s supposed to be. If I trigger script 2 from the gate:

2:
DEL 20: $ 1

Then X is correct a lot more often. I haven’t determined at what value of delay it’s 100% accurate.

I guess my question is: is this just how this works? Or could I have something else going on that would cause a slow reaction from this op?

4 Likes
#1496

thank you very much! :slight_smile:

#1497

I have not personally used a TXi but from the code it seems this is pretty much how it works. TXi polls its analog inputs and quantizes them on a timer once every 1000 us == 1 ms, and sends back the cached value when it receives an I2C message. This is presumably done to make responding to an I2C query very fast, whereas waiting for ADC conversions and quantizer calculations could hold up the I2C bus and stall Teletype if the new value was acquired on demand.

By contrast Teletype’s IN op does an ADC read immediately when the op is called. This still requires communicating with an AD7923 chip over SPI but this is much faster than I2C communication (limited by bus capacitance, i.e. wire length, the TXi end doing its thing, and in a multi-leader setup potentially having to wait for the bus to be free).

3 Likes
#1498

When working with my tiny er-301/teletype/ansible box, I realized that I was often wishing for a manual gate/trigger gesture with which I could trigger scripts in TT or affect things directly in er-301. So today I quickly rolled my own “expander”. :joy:

I think the whole thing cost me $10 or so. For gates and triggers I have one TT output send a steady 10V to the input on my 2hp thingie. This is hardwired to 4 momentary switches, and 4 outputs. So, pushing the button sends the voltage to respective outputs. Of course I could also send some other CV stream to that input, and then manually direct it to the outputs, but for now, I just wanted some way to manually fire scripts (without any interface attached to the box.)

Anyhow: I kind of like the fact that it’s just wires and switches. A sort of very specifically laid out, pre-wired, passive patchbay.

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34 Likes
#1499

Hello I had a question about the build, does the stripe o the opamp 4171 indicate top or bottom of the component? :slight_smile:

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#1500

The stripe is always the top, so pin 1 is to the left of the stripe.

1 Like
#1501

Thank you very much! :slight_smile:

1 Like
#1503

Finally got pusherman boards and soldered up all the SMT on a few units. Potentiometers seem to be in short supply, but finally got a few today to finish up my first test unit. Teensy (3.2) programs okay (0.18 and 0.21B firmwares), but when I go to read from it (TI.PARAM 1), TT (3.1.0) is freezing. Any suggestions on how to approach debugging this lil’ dude?

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#1504

I think its plugged wrong.
Where you have the ic wire go the adress jumpers.
Then you plug the ic cable to the connectors on the top left.
Hope this helps, i can take a picture later.

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#1505

Yeah, definitely seem to have that wrong! But the board isn’t labeled clearly, so I’m not sure what should be right offhand. I seem to have tried all of the possiblities, each resulting in a freeze or 0 for all values as if disconnected. But a step in the right direction! Thank you.

Edit: After checking Scanner Darkly’s post here:

Now I think I have it right?

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Still no dice on TT (plugged in via backpack), just getting 0 for all param’s and inputs, which is the same as if it weren’t connected at all… so. :thinking: Will have to sleep on it.

1 Like
#1506

I had some trouble as well. It’s weird, but try using the pins just to the right of the ones you have plugged in to, but keeping your actual plug aligned the same way. It’s a little strange. I found the i2c plug ins of the TT expanders from pusherman to be odd.

#1507

This is an issue in general with quantizing voltages, and it has a lot to do with the distance between the voltages. You might need longer delay values when covering wider intervals such as a 4 octave jump compared to a minor second. Looking forward to the next episode of Teletype Talk!

1 Like
#1508

Its that an old tt?
You might need a txn or teletype backpack ?
Just wondering…i had no problems with most length wires unless tgeir orientation was wrong.
Hope you get it fixed!

#1509

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make sure no jumpers are in the address pins (so that it uses the first address), and the highlighted area is where you connect i2c. the line at the bottom is the ground, make sure to connect ground to ground. shouldn’t really matter if you use left or right pins - this was for daisy chaining multiple devices.

if you’re just getting all zeros it might mean 2 things - either your i2c is still not properly connected (try a different cable, try a different i2c device if you have one with the same cable etc) or the connections on the txi itself are loose. i seem to recall @bpcmusic saying that when it’s too “perfect”, some connectors might float without good contact - try gently moving the boards against each other.

you don’t need a txn or a backpack with just tt and txi.

1 Like