Latch Switching Not Working

[marosell]

I have successfully built and uploaded the esp32doit-devkit-v1-wifi build onto the ESP32-WROOM-32U (DevKit C) card. I have Momentary switches working correctly to execute single-press MIDI commands. However, I can't correctly implement Latch switching (is this the same as toggle?) with my switches. I assumed I would be able to select "Latch" from the Pedal Mode drop-down and the switch would alternate between MIDI Value 1 and 2 on the Bank page, but it doesn't seem to work that way.

Can you explain how this is supposed to function, and does it use MIDI Value 3 somehow? Do I have the circuit connected correctly? (I have the buttons connecting the D-ports to ground).

[alf45tar]

A latching switch stays on until you press it again, and a momentary only stays on as long as you have your foot on it.

A momentary pedal sends CC or PC on press. Nothing happens on release. A latch pedal sends the same CC or PC on press and on release.

There are some exceptions. For example a momentary pedal sends a NOTE ON on press and a NOTE OFF on release.

MIDI Value 1, 2 and 3 have different usage. For example using and expression pedal sending a CC code, MIDI Value 1 and MIDI Value 3 are the minimum and the maximum values to send. MIDI Value 2 is also used for double press and MIDI Value 3 is used for long press.

A switch between D-port and GND is ok.

[marosell]

For switches between D-port and GND (for instance, I'm building an enclosure of only 6 momentary switches) do I still need to go back and add pull-ups to the A-pins? Or can we turn on the internal pull-ups for those pins in the code?

From the circuit diagram, I'm actually unclear as to why both a D-pin and an A-pin+PullUpResistor are required for each switch to ground; is the A-pin for the auto-sensing capability which turns the pedal on or off? (Forgive my naivety).

[alf45tar]

It is not required to connect a pull-up resistor to A-pins using only Momentary1 pedal. GPIOs 34 to 39 are GPIs – input only pins. These pins don’t have internal pull-ups or pull-down resistors.

If you do not select the Analog pedal mode you can leave A-pins floating without the pull-up resistor. If you insert a TS jack into the TRS port the Ring (A-pin) is grounded via the Sleeve. I connected Ring and Sleeve in Momentary 1 like in a TS jack.

[alf45tar]

ERRATA CORRIGE

A latch pedal sends the same PC on press and on release. A latch pedal sends CC MIDI Code on press and CC MIDI Value 2 on release. A latch pedal sends NOTE ON on press and NOTE OFF on release.

[marosell]

Out of curiosity, is there a reason why a TRS port switch cannot be used with Momentary1 (D and GND pins), by just grounding the ring with the sleeve together?

[alf45tar]

I think I didn't understand well you question. TRS port can be used with a Momentary 1 pedal.

PedalinoMini TRS ports can be connected to a TRS jack or to a TS jack. Using a TS jack, ring (A-pin) and sleeve (GND) are connected together. This is not a problem for the A-pin because there is a pull-up resistor and a Momentary 1 is a switch between tip (D-pin) and sleeve (GND).

[marosell]

I think I understand now. The circuit diagram on sheet 2/2 only shows TRS jacks on the left, including for the first example, the Momentary1 (which of course is valid for Momentary1).

What is not clear is that a TRS jack is not necessary for Momentary1. Only a TS jack is required (though not pictured), making the the resistor unnecessary for the A-pin. However, once a TS jack is used, it can ONLY ever be used for Momentary1 switching (and maybe Latch?) and never used for any of the other types of switches.

[alf45tar]

I confirm:

• TRS jack is not necessary for Momentary1
• if TS jack is used do not connect A-pin
• once a TS jack is used, it can ONLY ever be used for Momentary1 switching Latch1