Byron J.

Product SEN-12642 about 4 days ago

If you want a voltage that corresponds to the sound amplitude, the envelope pin should do that.

There’s an example sketch using an Arduino to read the envelope pin in the hookup guide.

You’re probably right about adding resistors. It will help keep loud sounds from overloading the output. If it’s possible, you can test out resistors by tack-soldering them in, or even just holding them carefully in place.

News - Enginursday: Digging into… last week

OK, it seems to be helping quite a bit.

I’m using the first circuit from page 7 of the datasheet - 330 on series from the WS-01’s 9V rail, and a trimmer across the adjust terminal. To get a suitable range from the trimmer, I had to put 10K resistors in series with the ends - otherwise it’s just too darn touchy.

I’m using it a the power supply for only the one MCP4725 - the other is still hanging off 5V. I’ve set the ref for 5.333V. I also recalculated the LUT in the firmware, so each semitone is 64 above it’s predecessor.

I’ve now got 49 keys of 1V/octave output, with a 0.5V range on the bender. Octaves are as in tune as I can get with the resolution of the trimpots.

News - Enginursday: Digging into… last week

Will it work? I don’t really know!

But we’ll find out shortly. I just grabbed a couple of them, and a couple of trimpots…

Product KIT-13146 last week

…and the “or don’t” is there because it’s much easier to poke and prod at the PCB if you leave the top cover off.

The first page of the quickstart guide has a pretty clear synopsis of the parts on the kit, and how they fit together.

News - Enginursday: Digging into… last week

I think it’s not so much that I need a DAC with a Vref input, but that I need a source of Vref to begin with! For all I know at the moment, a 7805 or LM317 would be solid enough, and could hang from the WS’s +9V rail. I don’t have much experience with voltage reference supplies, and I’m not sure what the right approach is. I’m digging into a pile of datasheets and looking at other people’s designs at the moment. I see the x0xB0x uses an LM336-5.0.

The MCP4725 seems to be OK at dividing Vcc by the right amount, so it’s probably up to the task, once I get the Vref sorted out.

There are a couple of other options - I could generate a regular voltage without regard for precise scaling, and then amplify/attenuate with a trimmer to get the scaling more solid.

I’ve also got plenty of unused pins on the Pro-Micro. I could build a 6-bit R2R ladder, as a 1-bit-per-semitone converter. Then I could use the two MCP4725’s for some combination of velocity/bend/mod/aftertouch.

Product KIT-13146 last week

No, what you see is what you get.

The heavy, silkscreened steel enclosure is part of the package.

News - New Product Friday: Slip … about 3 weeks ago

It became suddenly apparent that I wasn’t going to be able to talk to Rob just then.

Product KIT-11177 about 3 weeks ago

If you want the simplest connection:

• Tie the grounds on both boards together.
• Remove the speaker from the Gram Piano.
• Run a wire from the GP’s speaker ‘+’ terminal to the ‘IN’ terminal on the SP.

If you turn off all the waveform selector switches, you ’ll get the Gram Piano output, as filtered by the SparkPunk filter. If you turn on the waveforms, you get the GP mixed in with the SparkPunk.

If you’re a little more adventurous, you could put a potentiometer in between, configured as a voltage divider, to give you an input volume control.

Product KIT-12707 last month

I think there’s a step missing in there.

MIDI is a serial protocol, using digital messages to describe a musical performance. There’s a single line on there that carries all of the messages, which include note-on and off, clock synch, and other things like the sustain pedal and pitch bender. It’s a bit confusing, but 2 or 3 of the 5 pins in the MIDI connector are unused.

Even more confusing, Roland used the same connector when they implemented DIN-sync, one of the precursors to MIDI.

To turn MIDI into a clock suitable for the Sequencer, you’d need to use a microcontroller. It would watch for the synch related messages (start/stop/continue and clock pulses), and turn them into inputs for the sequencer. A Red Board with the MIDI Shield or MIDI breakout would get you most of the way there.

Product KIT-12707 last month

First off, I take it you’ve seen the section that describes synch in the theory and applications guide? I take it you cut the traces on the synch port, and are injecting the new signals on the pads marked “I” that are nearer the edge of the PCB?

Also, you might want to re-check the description of the run/stop and button signals. Run and stop should be logic signals that are the opposite of each other - “run” should be high when the sequence is running, while “stop” should be low. Then when stopped, they should trade - “Stop” should be asserted, and “run” should be low. You can use a voltmeter to verify that those signals are behaving correctly.

I’ve looked through Arturia’s documentation, and I’m not finding any description of getting a clock out of the unit. They mention CV and gate, but not clock. Do you have any links that describe external clocks you could share?