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16N Faderbank is Happening


#21

Just paid my deposit, excited!

My plan is to primarily use 16n to interface with the ER-301 over i2c. So, planning ahead and thinking out loud, I figured it would be worth sharing the steps to get 16n working with ER-301 as far as I understand them.

From the post that @jasonw22 shared, it sounds like a TXb isn’t required if the only thing I’m connecting from the 16n is the ER-301, I could just make a cable that goes direct from one to the other, correct?

My module is pre the i2c port fix so I’ll first have to follow these instructions to solder the shunt:

After that I’d have to make own cable. The above post shows the labelling of the pins on the ER-301 and according to this page here’s the wiring of the 3.5mm stereo jack on the 16n:

Tip: SDA
Ring: SCL
Sleeve: GND (ground)

Given what it says there, if the ER-301 is the only thing connected directly with that cable from the 16n it shouldn’t require a powered bus or the pull-up resistors, correct?

Other than firmware tweaks, am I missing anything?


#22

@iiii that all sounds accurate. It does mean you’ll have a cable entering your case and then snaking around the back of your ER-301. If that doesn’t bother you, then you’re good to go.


#23

Ha, yup, already got that happening with my uOC’s usb cable for the Hemisphere sequencing and midi/cv conversion, so why not have another? :wink:


#24

@iiii Thanks for collating this information - much appreciated! I was about to try & figure this out from the long thread :+1:t2:

@odevices Just for clarity I’m correct in saying that everyone who has an ER301 to date has to perform the hack if they want to connect the 16n I.e. the board update hasn’t been implemented into production yet?


#25

You are not correct :wink: All ER-301 sold since June 2018 have been revised to include an i2c connector that does not require any modifications:

http://wiki.orthogonaldevices.com/index.php/ER-301/Revisions


#26

Thanks - Glad I asked then :wink:


#27

Since the 16n is an external device the I2C lines will be unavoidably long. Therefore, you need pull-up resistors somewhere on the I2C bus. There is a footprint on the 16n for SDA and SCL pull-ups (R17 and R18) which are “do not place” by default but those could be populated for anyone running with 16n as I2C leader who doesn’t want any behind-the-panel mods in the rack.

There only should be one set of pull-ups on your bus btw.


#28

So what you are saying is, for the situation where a TRS cable is connected directly from the 16n to the 3 pins on the ER301 there also needs to be a resistor inline for the SDA and SCL connections? And that there’s already a place on the 16n to add these or you could just incorporate into the cable?
What value should the resistors be?

I’m planning on making my own 1U tile for connecting the TRS cable from the 16n to this and have a separate cable from the tile into the ER301 … super poor man’s TXb


#29

For those not paying attention to the 16n discussion over on Lines MichiganSynthWorks has announced he only has 7 units still available before he closes orders.


#30

Thanks for the heads up, @Unity2k.

I’ve been pretty on the fence about ordering one of these. Maybe someone can help knock me off.

At a glance 16 faders that can directly control 301 parameters with the flexibility to also do CV and MIDI sounds wonderful.

But I’m a little hung up on some of the details. The need to run 1 or more lines into my case from an external device, and the allowable length of that line. If it’s connected to an i2c bus with another master (Teletype), it may or may not cause problems. Does it need a TXb which is not currently available (and may be very difficult to get if I don’t get one within the first 5 seconds of when they go on sale?)

Granted, I have not been following extremely closely and may have missed or misinterpreted something here.

Does that sound right? How are others planning to use this with their ER-301?


#31

AFAIK, by default the 16n is not a master (but it can be configured to act as a master). You don’t need a TXb, you can use a TT backpack, you can create a fake TXb like I did, basically a 2hp panel with two stereo jacks connected to the TT backpack (or just one). The length of the cable: I understand that 45cm is a maximum but every i2c setup will be different. The latest posts in this thread are all about i2c etc :slight_smile: https://llllllll.co/t/16n-is-a-bank-of-faders-release-thread-current-version-1-31/18620/112

I’m planning to use one of the 16n I built with the ER301, via a Teletype. I will test the i2c connection tomorrow. (16n, Teletype, ER301, three TXo+)


#32

The SDA and SCL lines should be pulled-up to 3.3V using ~2.2kOhm resistors. These resistors run in parallel, not series. There isn’t a 3.3V bus on euro power so your tile would need a voltage regulator too. Or just populate the spots I mentioned on the 16n PCB and you can have a totally passive tile.


#33

Thanks, I’ll go with this then using 2.2K ohm resistors.


#34

I’d very much like one, but what @Joe said cleared my mind a bit : the entire thing seems a bit unclear and even convoluted. It’s absolutely to be expected of a project like this, and the people behind it have done a fantastic job with it, but for someone like me with no DIY background or electronics know-how, I’d need handholding to suss it out.


#35

So if the 16n is not a master, and Teletype is, it would work similarly to a TXi? Teletype would have to poll the 16n in response to a trigger (or Metro), and then push the fader value to a SC.CV on the ER-301?


#36

precisely yes


#37

Thanks for the tip, I had a suspicion that was the case. I messaged Raph at Michigan SW and said he could add the resistors to the board on my build.


#38

From the 16n readme

The “MASTER” version of the 16n firmware causes the 16n to emit commands directly to a number of modules. (You need to compile and/or flash it to your 16n over USB - see the README in the firmware directory). It sends CV values to up to four monome Ansible, four bpcmusic TXo, and the Orthogonal Devices’ ER-301 all at the same time.


#39

Would there be any disadvantage to placing them there? (Assuming there are no other pullups on the bus anywhere else?


#40

No disadvantage that I can think of. Keep in mind that both old and new TT hardware have pull-ups (they’re different though). I believe all the follower hardware (Ansible, ER-301, TXo, etc) are free of pull-ups.