ZynFace: CV/Gate + ThereMIDI

Xace · January 10, 2022, 9:43am

I’m trying to get just the TOF sensors working. Is there any other component involved appart to wiring VCC, GND, SDA and SCL?

I’ve looked at the source code, but could not make it out

riban · April 7, 2023, 2:42pm

I decided to play with my Roland SH-101 today. First I tried to calibrate it but found the power switch was bad and touching it will change the pitch of the synth. Looking at the service manual I see it uses two poles for power and another pole to switch a feed to calibrate the PSU. Maybe (hopefully) it is just a dry joint but I have put it back together now so an investigation for another day.

I plugged its CV/Gate inputs to the Zynface but cannot get it to do anything useful. The CV does not change and the gate is rapidly pulsing. Has anyone managed to get CV/Gate output from Zynthian working?

[Edit] The gate is not pulsing - it was an effect of the LFO on the synth. I am seeing a constantly asserted gate (+5V) and no CV (0V).

tunagenes · April 7, 2023, 4:10pm

Perhaps this could be considered a feature instead of a defect and used to good effect?

riban · April 7, 2023, 4:22pm

That is what my son said! I think it may be a hard sell to any potential buyer if I ever sell it!

riban · April 7, 2023, 6:33pm

A few issues I have found so far:

I think you have to manually specify the I2C addresses for the extender modules
Relevant MIDI is not routed to ZynMaster so MIDI to CV conversion does not occur
Configuring CVgate Out actually changes the socket on ZynFace labelled Gate In
Gate is inverted, i.e. sits high, going low when a note is played
I can’t get any CV to change value from 0V

Baggypants · April 7, 2023, 7:04pm

Power expression.

wyleu · April 7, 2023, 7:07pm

Didn’t old Hammond have something similar…?

jofemodo · April 7, 2023, 9:36pm

Hi @riban!

It’s been a long time i’ve no tested the zynthian CV/Gate functionality. It could be broken by some recent change in zyncore library,

Last time i tested, more than 1 year ago, it worked perfectly, input and output. My test platform was composed of:

Korg SQ-1 analog sequencer
Behringer Crave analog synthesizer
Zynthian V4 with Zynaptik Extended + Zynface

I will check ASAP. Thanks for the feedback.

Regards,

riban · April 7, 2023, 9:38pm

It’s a long (Easter) weekend and so time to play. (The alternative is to work on the house and those control voltages feel more appealing.)

tunagenes · April 7, 2023, 10:06pm

On a somewhat related note, jofemodo what is the status of “ZynFace KIT”?

By status, I mean - I noticed in the store it is “sold out” - do you plan to ‘restock’? Before or after the Zynthian V5 or?

Hengy · May 1, 2023, 11:10am

Hi,
Just a quick question before i get a zynface board fabricated (assuming you are not getting any back in stack soon); is it compatible with the Zynaptik-2 module (with the MCP23017/MCP4728) which is what i have in my zynthian?

I’ve just started getting into eurorack and been happily making modules and creating happy noises. Now i really want to get cv in/out of my zynthian , something to do while waiting for V5

wyleu · May 1, 2023, 3:22pm

Not used a new zynface myself, others may confirm but the configured i2c address within the zynth family is all that needs to differ.
i2cdetect-rack

i2cdetect -y 1 is the magic one mutters, to make it all visible but I haven’t ever seen a table of the values used but 0x20 I’ve got a zynaptik MIDI ( can’t remember which version, probably pretty early)

The Zynface original board I have in my pedalboard shows up as 0x21 so I presume, but nothing more , that it’s hung on there in the current board.

jofemodo · May 4, 2023, 9:54am

Hi guys!

I’ve a few zynface kits for selling but we decided to remove them from the shop because people was buying without reading carefully the description, thinking that it can be connected to “any” zynaptik module and causing confusion and frustration on both sides.

But … if somebody having a zynaptik-2 module wants/needs a zynface kit, i would be really pleased to sell it. Simply tell me

Also, we have some “zynaptik-1 customization kits”, that allow to extend zynaptik-1 modules so they can be used with zynface.

Enjoy!

Hengy · May 6, 2023, 7:53am

Thanks.
afraid i already fired off an order for the bare boards from JLCPCB

magneticstripper · August 9, 2023, 12:46am

any magic out there for switching the TOF sensor ranges so being closer is higher?

magneticstripper · August 13, 2023, 8:58pm

i cringe to ask this out loud… can i flip the min max in the zyntof.c:

#define MIN_TOF_DISTANCE 60
#define MAX_TOF_DISTANCE 600

???

if so, what is the procedure for recompiling?

jofemodo · August 14, 2023, 9:41pm

I doubt it works. You better edit zyntof.c and invert the “v” value in the “send_zyntof_midi” function, like this:

void send_zyntof_midi(uint8_t i) {
	uint32_t v;
	if (zyntofs[i].val<MIN_TOF_DISTANCE) {
		v = 0;
	} else if (zyntofs[i].val>MAX_TOF_DISTANCE) {
		v = 16384;
		return;
	} else {
		v = 16384 * (zyntofs[i].val - MIN_TOF_DISTANCE) / (MAX_TOF_DISTANCE - MIN_TOF_DISTANCE);
	}
	v = 16384 - v;
	if (zyntofs[i].midi_evt==PITCH_BEND) {
		//Send MIDI event to engines and ouput (ZMOPS)
		internal_send_pitchbend_change(zyntofs[i].midi_chan, v);
		//fprintf(stderr, "ZYNTOF [%d] => MIDI %d\n", i, v);
	} else {
		uint8_t mv = v>>7;
		if (mv!=zyntofs[i].midi_val) {
			//fprintf(stderr, "ZYNTOF [%d] => MIDI %d\n", i, mv);
			zyntofs[i].midi_val = mv;
			if (zyntofs[i].midi_evt==CTRL_CHANGE) {
				//Send MIDI event to engines and output (ZMOPS)
				internal_send_ccontrol_change(zyntofs[i].midi_chan, zyntofs[i].midi_num, mv);
				//Send MIDI event to UI
				write_zynmidi_ccontrol_change(zyntofs[i].midi_chan, zyntofs[i].midi_num, mv);
			} else if (zyntofs[i].midi_evt==CHAN_PRESS) {
				//Send MIDI event to engines and ouput (ZMOPS)
				internal_send_chan_press(zyntofs[i].midi_chan, mv);
			} 
		}
	}
}

Note the added line:

   v = 16384 - v;

Recompiling is really easy. Simply run the “build.sh” script in the zyncoder folder.

If it works as you want, please, open a “feature request” in our tracking system and i will consider adding a config option for this, OK?

Regards!

magneticstripper · August 16, 2023, 10:56pm

This did work to reverse the readings. i noticed in the midi log that after 127, it flips back to 0, which is kindof non optimal. on pitchbend it would be awesome if non-interaction (max?) set the reading back to 0… like a spring loaded wheel. Thank you for the suggestion!

jofemodo · August 17, 2023, 10:40am

Nice. Please, tell us about your experiments with this . In fact, the “official” code is also quite experimental so, there is a lot of room for improvements.

Thanks!

hannesmenzel · March 10, 2025, 12:46pm

Hacking an old thread again, it seems suitable for my question.

I saw with much exitement the use of these distance sensors above and directly wanted to have one or two of them in my cigar box. I’d like to ask some questions about these:

I saw from the picture of @riban above you used a sensor named VL53LO. My local dealer offers some similar products. What do I have to take care of? I saw that some use static adresses, which might be difficult to implement, some seem to use adress pins. This for example seems to have printed a static adress of 0x29 to the board, but the page sais 0x52. Some of the units only expose voltage and I2C connections, other add additional connectors (X-SHUT, GPIO1, …). I actually didn’t find out how to configure and adress them since the webconf page only askes for the number of distance sensors. I do not have any Zynaptic board whatsoever but only one mcp23017 for the knobs right now.

Can somebody provide an idea how to implement one or two of them in a custom build?