latigid on
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Posts posted by latigid on
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Like it! Nice job!
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Have you though about a piezo trigger? You may get a lot of feedback with a microphone. For this too you'd need a processing circuit as I think piezo elements can generate a high voltage (low current).
This one is very simple (open source):
http://musicthing.co.uk/modular/?p=933It might be quite difficult to separate the rim and body sounds.
The Zener (better Schottky) diode would be unnecessary if you used a rail-to-rail op amp powered at 3v3 and your scaling circuit was tailored to give a correct signal voltage.
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Do you mean you want to assign a track to an AOUT port? This would be done by setting up the track on the AOUT channel of your choice.
You can also route a MIDI input to an AOUT port just like a MIDI-CV converter.
Or do you mean something else? It's not so clear from your question.
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DIAMEX PIC PROG works fine and is the recommendation of TK. Or, send the PICs to one of many on the forum and we can program them for you :).
I had two PICs from SmashTV (since several years) two from Mike (since a few years) and two virgin ones from Mouser. Of the pre-burned ones, one was faulty, even after erasing and re-flashing. So I'm sure the PICs from Mike had the bootloader burned in, but maybe a handling error on my side caused an issue. In any case, I have the Quad IIC working well now!
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Okay, I understand what you mean. LED brightness does depend on the current limiting resistor, but it's a non-linear relationship. Brightness is much more dependent on the pulse width (or pulse density). I think the duty cycle in the BLM is 10%, not so easy to calculate brightness.
The red LED does have a lower Vf, but also a lower mcd rating than green. In my experience, 220R was a good balance for both red and green LEDs. You might also get some feedback from others here who have mixed red and green LEDs in their builds.
If you want, here is a shared OSHpark project for very cheap test boards, you could also check the fitting of your new LEDs.
https://www.oshpark.com/shared_projects/I9xfP7XE
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If the wiring is very old, then earth might be connected to the neutral line. It's not very safe in any case. Sounds like you need an electrician to look at it rather than internet strangers.
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Looks great! 3mm thick? I'd imagine it's stiffer than acrylic?
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Just now, modulator said:
How are the LEDs and Resistor-Networks connected?
Check the SCALAR circuit, the networks are bussed for the switch anodes and isolated for current sinks and limiting. There's no real reason to use networks apart from being easier to solder.
Just now, modulator said:There are 5x8 Resistors with 220 Ohm and 5x8 Resistors with 56 Ohm (blue LEDs).
Forward-Voltage of the LEDs is 3.3V.
The choice of Resistor-Network-Values is not really big ...
Blue and green have different mcd values. The 56R/220R choice was to balance the brightness, or did I not understand you properly?
Just now, modulator said:Some thoughts to the Voltage-Booster:
In my opinion a Voltage-Drop is not good in any way.
It is a "solution" to force the Voltage to a certain level but the question is what is the problem.
Perhaps some small Resistors (Connections, Cable-Lenght (e.g. 0,2 Ohm and 0,8A --> 0,16V Drop) or
The single cable is a way to keep things tidy, but not ideal, I agree with you there. It's also the simplest way to power the BLM from the Quad IIC board, where the optocoupler and pull ups on the MIDI circuit share the same rail. If they were separate, a higher voltage could be sent through the single cable and regulated locally. When this was first designed 5 years ago, TK. used common low Vf, low brightness LEDs, so high current consumption was not an issue.
Just now, modulator said:the Source is to weak (USB-Powered).
2A SPSU on my build, I recommend to power the Core or at least the Quad IIC module with a decent supply.
Just now, modulator said:A real solution would be to use a separated external PSU for the BLM or to lower the current-consumption.
Some cases have extra holes for this purpose, but I don't know of any working builds using them as of yet. You could try larger resistors at the expense of overall brightness.
Just now, modulator said:I will use an external PSU (2-3A).
If you got a Voltage-Drop because of the LEDs, that could mean that the PSU (USB-Source) is operating above its maximum-rating.
See above.
For the next run I will modify the miniCore board to take an adafruit "Verter" regulator. This is the simplest option and it works in at least two builds so far (@jbdiver). You are also welcome to connect an external PSU here at the expense of one extra cable to plug in. But with a right-angled DC jack it hopefully isn't too messy.
I think the voltage drop is partially due to the regulated source being distant from the load, but also inherent to the circuit. Especially with bright LEDs, we're switching a lot of current quite fast, and it could be a speed limitation of using shift registers in this way. I'd hazard a guess that MOSFETs would be better current sinks, but I'm not an expert at such things. My low-level understanding is that you need special types to use a +5V gate voltage, otherwise the transistor isn't fully turned on.
In common use, it would be rare to have even 1/4 of the LEDs active at a time, so while not a perfect design it should be okay for most people.
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Because the PSU chassis is plastic, I would say that the earth pin is not necessary. But this is mains voltage and you have to be careful... There's no easy way to remove the pin without hacking apart an IEC connector.
Can you try with a linear PSU instead?
EDIT: I don't advocate removing the earth connection if the device expects one. As we learned later, the OPs house uses non-earthed main sockets which clearly contribute to the problem.
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Looking at the diagram here it's probably the expected behaviour, as +15V is always present. If the polarity was reversed the electrolytics would go pop and nothing would get through the regulators. So the next question will be about the 15VDC PSU, what is the model/do you have a picture? If it has a metal frame and earth pin, do you get continuity between it and the 0V line in the MB-6582?
FWIW I did a similar mod on my build, but I use a linear (transformer-based) 12VDC PSU as input. This means that the device is electrically isolated via the transformer.
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For me you still haven't explained the problem well. Because this is a modified build, you need to clearly document all changes here. Like drawing all bridges/cuts/substitutions/omissions on the layout file -- it doesn't have to be a work of art, you could use Windows Snipping Tool or a screenshot with a basic drawing program. Please don't expect others to go through all of the disparate threads and collate the info for you.
I'm happy to try troubleshooting if you give some more info.
And I repeat my "stupid" question above; does the MB-6582 power up only if the DC adaptor is plugged in and switched on? What is the voltage? What kind of PSU is it?
How is the other equipment powered?
It's important to check your wiring, because there are some complicated powering schemes possible in the MB-6582. Some involve adding two rails together which only works in certain circumstances, and also means "ground" is not always 0V! I assume you're only want to use 9VDC for the SIDs, which means you should come in with ~12VDC and regulate down to 9VDC.
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What PSU are you using? The C64 one? Does the board pass the voltage tests like this?
Do you mean it powers up with no PSU connected? That's pretty strange if so; perhaps you have a wiring problem in your house? You could have mains voltage where it shouldn't be. Check again through Wilba's layout that you've made the correct mods and upload an annotated image here to confirm.
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30 minutes ago, Rowan said:1 hour ago, latigid on said:
Can you comment on your preferred layout of parameters? I.e. most functions accessible from encoders or more "voice" oriented pages?
I'm still undecided on this, an ideal solution would be both! A Voice/channel mode that detailed settings are made for a single channel and a Performance/Multi mode where a set of parameters can be adjusted across multipul channels.
An example of Performance mode would be the 4x4 encoders assigned to ENV2, you could control the ADSR of 4 channels without any paging.
Right, so now we have three concepts of paging:
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8/4/2 Voice mode (TK.'s choice) which is like a traditional MIDI-CV
- e.g. 4 voice with pitch CV, filter CV, gate and trigger; encoders are arranged in blocks within a voice and menus are used for finer tweaking.
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Single parameter mode (my choice) where all modulator depths across a single channel are accessible on one page, and specific parameters of modulators are on others. Each modulator is thus tweaked on a channel basis; see the mockup picture:
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e.g. Channel 1 is selected from the 4*4 button grid
- the encoders are colour-coded to match modulators represented on the bottom half of the button grid and adjust depth only on Channel 1.
- Env. 1 is pressed, the encoder field changes to yellow and all stages/other parameters can be tweaked. Unused encoders are unlit.
- For transpose and tuning, there's the "keyboard" layout of buttons and a dedicated encoder
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e.g. Channel 1 is selected from the 4*4 button grid
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Multi parameter mode (your idea, kind of a hybrid between those above) assigns encoders to specific controls across multiple channels,
- e.g. ADSR of Channels 1-4. You'd have to make some judicial decisions when more than four useful parameters were needed.
We'll have to test the hardware to get a good idea of the most useful workflows, but hopefully it's flexible enough to accommodate everyone's needs.
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8/4/2 Voice mode (TK.'s choice) which is like a traditional MIDI-CV
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Agreed about the dimensions, and following your suggestion these PCBs are 100mm tall, 420mm total width which will definitely fit in an 84 HP case. The only problem being that there's no room for the connectors -- as such a 126HP case (25.2"/640mm usable width) could be a better choice if you wanted them front mounted. The LRE board and displays etc. will be difficult to fit into 3U.
The Wilba SEQ PCB is 121.92mm tall, which will is fine for 3U but doesn't take Eurorack mounting rails into account. My plan is to buy or make some sort of standard 19" road case and have the SEQ, CV and CV breakout panels mounted and powered off a decent triple PSU.
14 minutes ago, Rowan said:I've mounted the AOUT and DOUT in my Eurorack case and connected these to the Core/CS with the line driver. My use case is as a 8 CV out modulation generator.
Can you comment on your preferred layout of parameters? I.e. most functions accessible from encoders or more "voice" oriented pages?
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6mm switches (4.5/6.5mm lead spacing) are now implemented with a
1.51.6mm vertical offset relative to the D6s. Any others?Prog. and Tempo labels reinstated.
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TK. asked me to rework the PCB, so after a bit of down time on a delayed train:
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It's the same basic layout as before, except that the shift registers are on board. This means only a single ribbon connector to the Core is needed = easy wiring.
- or could we feature-creep an LCD/OLED in?
- Accordingly there are some pullup/current limiting resistors added, but the 595 should be able to sink the cathode rows without transistors.
- 3* SOIC16 chips, 3 1206 caps, very easy to solder! The remainder is THT.
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OCD dummy resistor package if you want it to look more symmetrical
- Expansion header e.g. for DOUT gates etc.
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I adjusted a few labels, like changing Tempo to BPM to be more consistent with the SEQ,
Program is spelled out fullyit's progression isn't it? and Record modes are factorised. - More mounting holes.
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Switches are the D6 type because:
- reasonably priced
- readily available
- multiple colours (and shapes like square and flat round) possible
- high quality, they still work well in a project I started 10 years ago
It might be possible to add another switch footprint, so tell me if there's a particular switch you'd like to use and I'll see what I can do. I won't consider the TL1100 series because they exhibit serious problems with reliability after a year or two.
As long as there's interest I'm happy to do a PCB run.
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It's the same basic layout as before, except that the shift registers are on board. This means only a single ribbon connector to the Core is needed = easy wiring.
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How about "Rude" as in Mackie's Rude Solo lamp?
Maybe this mode could be implemented as a new parameter layer, which would give control over each step. If one step in a Rude# buss has a higher value its Gate will take priority.
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Suggest to keep the detents, you have a good amount of off-axis torque on the large wheel. I think smooth encoders work well on more "analogue" controls, like the MB-6582. For incremental changes (low resolution, high precision needed for e.g. sequence lengths) stepped is much better.
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I would hazard a guess that the caps are 20% or worse tolerance anyway? Have a go I say.
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Hello,
I used the recommended cutout size of 2mm, so your suggestion might fit (very snugly). The spec looks very similar, and the pricing is fair for low quantities.
Drawbacks are that It's not specifically a reverse-mount LED and the lack of rear marking would make soldering them more tedious/error prone. They're also untested, but likely the same LED die.
I still need to look at wholesale pricing, probably from China in full reels. For a bulk order I might be able to offer them at 10c each.
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Looks like a really nice setup! Also good work on the BLM reimagination.
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Meine Programmierfaehigkeiten sind schlimmer als mein Deutsch! Aber ich glaube, dass du solltest eine Metaevent modifizieren. Dann man kann ins Editorprogramm die Taster und Event verbinden.
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A real bible! Thanks so much for your considerable efforts!
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As far as I know, there's no circuit diagram for the SEQ PCB, but you could trace the layout pretty easily. Are you familiar with the concept though? A button matrix scans inputs via DIN and sends pulses on the DOUT chain to close the circuit. It's not high-level programming, but you could load up MB_NG and define a button matrix to test the concept. @Sauraen just made a CS for his SEGA Genesis build, perhaps he has some advice.
Bongo Triggers > velocity > piezzo electrete > ain trigger >
in MIDIbox NG
Posted
Good luck! I know a lot of professional drum triggers use this scheme. E.g. ddrum; they also have a "brain" which must be a simple ADC to MIDI. Bare piezo elements cost almost nothing, although you may need to experiment with the damping material e.g. a piece of foam.
Zeners have a fixed breakdown voltage (wide range available), whereas Schottkys have a lower forward voltage than a standard PN junction (4148). The normal idea with MCU pin protection is to use Schottkys as a shunt. The lower Vf is, the more range you have, as the clipping point is the reference voltage (upper limit) - Vf. To protect from overvoltage you connect the anode to the pin and the cathode to 3v3. This ensures nothing greater that 3v3 can pass, it's also normal to include one or two current limiting resistors. To protect from undervoltage you connect the anode to ground and the cathode to the pin.
I would suggest using the op amp itself as a limiter, because it's impossible for the output to swing past the power rails. There are protection diodes at work here too, so you need a rail to rail op amp in order to maximise the signal transmission.