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Richarius
Joined: Feb 22, 2014 Posts: 81 Location: Kitchener, Ontario, Canada
Audio files: 1
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Posted: Tue Aug 07, 2018 6:52 am Post subject:
Lunetta with Euro interfacing problems ... anyone else? |
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In working on a patch for the Deathlehem Jazz Quartet, I have found at least 2 different manufacturer modules, that will NOT drive my Lunetta modules at all:
- Mutable Instruments Branches
- Ladik Bool2 - logic module
- Bastl Knit Rider
The module's inputs that they would not drive are:
- CD4052 A and B control inputs (100k Grounded)
- CD4015 Clock and Data inputs (100k Grounded)
Thoughts, anyone?
I'm going to check the datasheets for the MI and Ladik modules to see what their outputs are. Though - if they're only +5V, that still should not matter to the 4052 and 4015 which are not Schottkey input doohinkeys ... stumped.
Thanks for any potential help here. I ain't none pro or anything. Just a hacker. _________________ https://tsol.space/crafting/composing-music/albums/ - my punk, ambient and experimental tunes |
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Richarius
Joined: Feb 22, 2014 Posts: 81 Location: Kitchener, Ontario, Canada
Audio files: 1
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Posted: Tue Aug 07, 2018 7:29 am Post subject:
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All 3 that I mentioned above, have +5V outputs. Dammit.
In 1 of my up'n'coming 'Utility' modules, I'll include comparators, to take care of that problem. _________________ https://tsol.space/crafting/composing-music/albums/ - my punk, ambient and experimental tunes |
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JovianPyx
Joined: Nov 20, 2007 Posts: 1988 Location: West Red Spot, Jupiter
Audio files: 224
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Posted: Tue Aug 07, 2018 9:00 am Post subject:
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I'm not familiar with the driving modules, but since you mention 5 volts, I have to wonder about PSU voltage differences.
CMOS "likes" to have an input swing that matches the CMOS PSU. As such, if +12volts and ground are used for CMOS, then the CMOS inputs want low levels of zero and high levels of 12v.
CMOS that uses a PSU of 5 volts wants to see high levels at +5v and low levels at zero. In this case, using modules to drive it with PSUs of more than 5 volts can cause problems and can even damage the CMOS. This is because there are anti-static diodes built into all of the inputs. These diodes are meant to conduct with extremely low current. When too much current is supplied, these diodes can internally melt and that will destroy the IC.
Often modular devices have their own designer provided protection circuitry on their inputs because the designer can't know what the user will connect to it. These protection circuits run the gamit in terms of exact design, but will work within reasonable limits (such as, don't try to drive a module with your 50 Hz mains voltage). Lunetta circuits typically do not include such circuits. This is partly due to the philosphy of Lunetta being simplicity and if the Lunetta synth is all Lunetta running from the same PSU, then protection circuits really aren't needed. When you move to a hybrid system of Lunetta and other kinds of modules, then you have to include the protection schemes or damage may result.
CMOS can also have schmitt trigger inputs. Normal CMOS inputs need an input slightly above (Vdd-Vss)/2 to trigger a high and slightly below to trigger a low. Keeping the input voltage near (Vdd-Vss).2 is not particularly wise as noise can cause the gate to switch states "unexpectedly". For non-schmitt inputs, it's best to get the input close to Vdd for a high and close to Vss for a low. Schmitt trigger inputs create a no-man's land around (Vdd-Vss)/2. The input must rise above the no-man's land to cause a gate switch to high, and must go below no-man's land to switch to a low state. If the input stays in no-man's land, no switching occurs. Schmitt trigger inputs were introduced to make the gates more immune to noise.
The only exception to these rules comes when using a device like 4069UB in what is called a "linear amplifier" where the device acts like a sort of crappy opamp. In that case, the input voltage can be analog that goes from Vss up to Vdd. However, even in this case, you never want the voltage to go above Vdd nor below Vss.
Since I can't see all of what you're doing I can't analyze the problem any further. I hope what I've written helps you (or anyone reading) to get Lunettas working in a hybrid system and to prevent damage to your devices. _________________ FPGA, dsPIC and Fatman Synth Stuff
Time flies like a banana. Fruit flies when you're having fun. BTW, Do these genes make my ass look fat? corruptio optimi pessima
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Richarius
Joined: Feb 22, 2014 Posts: 81 Location: Kitchener, Ontario, Canada
Audio files: 1
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Posted: Fri Nov 01, 2019 7:57 am Post subject:
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JovianPyx wrote: | I'm not familiar with the driving modules, but since you mention 5 volts, I have to wonder about PSU voltage differences.
CMOS "likes" to have an input swing that matches the CMOS PSU. As such, if +12volts and ground are used for CMOS, then the CMOS inputs want low levels of zero and high levels of 12v. |
Omg - I'm sorry for the length of delay in reply! But my DIY last year were short lived. Been back to it, since August of THIS year though.
Thank you for the above point of clarification for CMOS. I hadn't ever considered that. :-/
I did build a quad 2x input amplifier and it has taken care of most interfacing issues from Euro to Lunetta. Most. Trig / Gate seems to be another problem.
Or 'length' of pulse I'd thought. Someone else recently said that doesn't matter. Hmmm.
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CMOS that uses a PSU of 5 volts wants to see high levels at +5v and low levels at zero. In this case, using modules to drive it with PSUs of more than 5 volts can cause problems and can even damage the CMOS. This is because there are anti-static diodes built into all of the inputs. These diodes are meant to conduct with extremely low current. When too much current is supplied, these diodes can internally melt and that will destroy the IC.
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I have been very careful there, when I've had standalones, running on +9/Grnd. I try to keep it all now though, at +/-12V to be compatible.
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Often modular devices have their own designer provided protection circuitry on their inputs because the designer can't know what the user will connect to it. These protection circuits run the gamit in terms of exact design, but will work within reasonable limits (such as, don't try to drive a module with your 50 Hz mains voltage). Lunetta circuits typically do not include such circuits. This is partly due to the philosphy of Lunetta being simplicity and if the Lunetta synth is all Lunetta running from the same PSU, then protection circuits really aren't needed. When you move to a hybrid system of Lunetta and other kinds of modules, then you have to include the protection schemes or damage may result.
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Very true. I have often 'broken the rules' of Lunetta but I don't really care. If I'm not mistaken, I'm still going in the original 'spirit' intended by My. Lunetta.
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CMOS can also have schmitt trigger inputs. Normal CMOS inputs need an input slightly above (Vdd-Vss)/2 to trigger a high and slightly below to trigger a low. Keeping the input voltage near (Vdd-Vss).2 is not particularly wise as noise can cause the gate to switch states "unexpectedly". For non-schmitt inputs, it's best to get the input close to Vdd for a high and close to Vss for a low. Schmitt trigger inputs create a no-man's land around (Vdd-Vss)/2. The input must rise above the no-man's land to cause a gate switch to high, and must go below no-man's land to switch to a low state. If the input stays in no-man's land, no switching occurs. Schmitt trigger inputs were introduced to make the gates more immune to noise.
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That's what I have liked about the Schmitt for the Clocks. In quite a few cases I moved to the 4093 to stay away from offshoots due to the noise.
I'd read and still have it in membery at 2/3 x V+ for HIGH and 1/3 x V+ for LOW, which I've tried to keep to, in those cases.
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The only exception to these rules comes when using a device like 4069UB in what is called a "linear amplifier" where the device acts like a sort of crappy opamp. In that case, the input voltage can be analog that goes from Vss up to Vdd. However, even in this case, you never want the voltage to go above Vdd nor below Vss.
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I've seen it everywhere, but I never have tried it in my own circuits. Only 1 of ... Ray Wilson's?
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Since I can't see all of what you're doing I can't analyze the problem any further. I hope what I've written helps you (or anyone reading) to get Lunettas working in a hybrid system and to prevent damage to your devices. |
I do greatly appreciate your help sir! You always have been a wonderful assistance to many of us, that I've seen over the years. Appreciated.
---
Just got an Arduino UNO R3 in the mail, for the cost of shipping. Makes 2 x UNOs now. Time to get back to teaching myself it's code as I really really REALLY want to get some simple sequencing tools made by myself, that don't seem to be available out there ... by themselves. (Chance of playing each step; set by user. Play / Skip / Pause, like the Moog 960. I know there're others. Simple first, to learn, anyways. ) _________________ https://tsol.space/crafting/composing-music/albums/ - my punk, ambient and experimental tunes |
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Steveg
Joined: Apr 23, 2015 Posts: 182 Location: Perth, Australia
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Posted: Sat Nov 02, 2019 4:53 am Post subject:
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Hi Richarius,
I'm not entirely sure what you are doing But it sounds like you are using a 5V supply module to drive a 12V supply CMOS chip?
If that is true you need to do some level shifting to ensure that there are no problems.
One problem you will have is that the 5V will never register as high unless it reaches move than half the CMOS voltage. Early chips didn't always transition at 1/2 VCC bit modern ones seem to. So 1/2 x 12V = 6V wich means 5V never registers as high.
As long as you are passing digital signals and you don't have a problem with inverting the signal then a simple NPN transistor can be used as a buffer. |
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Richarius
Joined: Feb 22, 2014 Posts: 81 Location: Kitchener, Ontario, Canada
Audio files: 1
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Posted: Sat Nov 02, 2019 6:14 am Post subject:
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Steveg wrote: | Hi Richarius,
I'm not entirely sure what you are doing But it sounds like you are using a 5V supply module to drive a 12V supply CMOS chip?
If that is true you need to do some level shifting to ensure that there are no problems.
One problem you will have is that the 5V will never register as high unless it reaches move than half the CMOS voltage. Early chips didn't always transition at 1/2 VCC bit modern ones seem to. So 1/2 x 12V = 6V wich means 5V never registers as high.
As long as you are passing digital signals and you don't have a problem with inverting the signal then a simple NPN transistor can be used as a buffer. |
Hey Steve. Thanks for your input.
No ... it were the above mentioned modules (commercial companies) that are running in a 12v system (+/-) are output +5V / Ground as their standards.
Most of the time where I've had to interface them with my 12V I/O of Lunetta stuff, is where my quad 2X amplifier module has come in handy.
(For each of the 4 channels, I do have a 100k attennuator (omg, SP??) in the opamp pair's feedback path, to amplify up to, 2X the input value.)
My biggest problem area has been the Clocking / Data interfacing with the CD4015 dual 4 BIT Shift Register. I regrettably haven't had the patience to properly study it's functionality from the datasheet, to fully understand how to work with it. _________________ https://tsol.space/crafting/composing-music/albums/ - my punk, ambient and experimental tunes |
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