Gecho v2 Channels

Firmware 1.0.116

1-4: Meditative soundscapes & demo songs

• Sensor S1 controls delay as usual.
• Sensor S2 lowers background sample mixing level.
• Sensor S3 increases filters resonance.
• Sensor S4 adds arpeggiator effect.
• Button B1 switches between high-pass and low-pass filtering (the default varies by channel).
• Button B2 generates new random chord progression.
• Buttons B3,B4 control fixed delay and inputs as usual.
• Button SET starts binaural beats. Press repeatedly to select one of the 4 programs.

11: The original channel #1 (from v1 model)

• Holding button B3 decreases input levels.
• Holding button B4 increases input levels.

12: Song of Wind and Ice

• Button SET starts isochronic tones. Press repeatedly to select one of the 4 programs.

13: White noise

• This channel has no interactive controls. It emits mathematically generated white noise, the generator is pseudo‑random, not a true RNG.

14: Bytebeat

A chiptune-like mathematically generated "songs", as demonstrated in this video.

• Button B1 select next song. There is 8 sogns and the current one is indicated by respective red LED.
• Button B2 adjusts stereo panning. There are 4 levels and the current setting is indicated by pairs of red LEDs.
• RST+B1 decreases the playback/calculation speed.
• RST+B2 increases the playback/calculation speed.

23: Infinite looper with LPF, HPF & flanger New!

• Sensor S1 controls delay as usual. You can think of delay here as if it was "tape loop length". Button 3 overrides this sensor.
• Sensor S2 raises cut-off point of the high-pass filter.
• Sensor S3 lowers cut-off point of the low-pass filter.
• Sensor S4 adds flanger effect, the maximum range is almost 3 octaves down (perceived pitch).
• Button B1 decreases speed, current setting is indicated by blue LEDs.
• Button B2 increases speed in a similar way.
• Buttons B3,B4 control fixed delay ("tape length") and inputs as usual.
• RST+B1 lowers the delay persistence, i.e. ratio of how much signal is mixed back to the loop. Range is from 32/40 to 39/40, default at 38/40. Current level is indicated by white LEDs.
• RST+B2 raises the delay persistence in a similar way.

24: Infinite looper with warping and reversible delay New!

• Sensor S1 controls delay as usual. You can think of delay here as if it was "tape loop length". Button 3 overrides this sensor.
• Sensor S2 reverses playback and recording direction.
• Sensor S3 decreases speed, the range is from 1x to 1/2x (one octave down).
• Sensor S4 increases speed, the range is from 1x to 2x (one octave up).
• Button B1 decreases speed, current setting is indicated by blue LEDs.
• Button B2 increases speed in a similar way.
• Buttons B3,B4 control fixed delay ("tape length") and inputs as usual.
• RST+B1 lowers the delay persistence, i.e. ratio of how much signal is mixed back to the loop. Range is from 32/40 to 39/40, default at 38/40. Current level is indicated by white LEDs.
• RST+B2 raises the delay persistence in a similar way.

31: Granular sampler

• Sensor S1 controls detune, first 4 levels (indicated by 4 red LEDs) cause slight detune, the remaining levels cause stronger detune.
• Sensor S2 enables sampling of the new material. Triggering this sensor to a higher level increases stereo spread.
• Sensor S3 changes basic chord between major and minor when temporarily triggered.
• Sensor S4 increases number of voices, the range is 3 to 27.
• Button B1 loads one of the pre-programmed demo songs and plays it. Fixed!
• Button B2 loads user-programmed chord progression (see channel #111). Fixed!
• Buttons B3,B4 control fixed delay and inputs as usual.

32: Decaying reverb

• Sensor S1 controls delay as usual.
• Sensor S3 raises cut-off point of the low-pass filter.
• Sensor S4 shortens the reverb buffer length (so it sounds like if the pitch went up).
• Button B1 adjusts the direction of decay upwards. Current setting is indicated by blinking red LEDs. Two middle LEDs blinking means the decay is stopped.
• Button B2 similarly, adjusts the direction of decay downwards.
• Buttons B3,B4 control fixed delay and inputs as usual.

33: Dekrispator

• Button B1 browses to the previous patch (patches are defined in config file).
• Button B2 browses to the next patch.
• Buttons B3,B4 control fixed delay and inputs as usual.
• RST+B1 loads the recent user-generated patch from persistent memory.
• RST+B2 loads a new sequence (sequences are defined in config file).
• Button SET enables more options, press it once and orange LEDs will start blinking.
• Button B1 while options enabled generates new "effects" part of the patch. The new patch is stored in persistent memory.
• Button B2 while options enabled generates new "parameters" part of the patch. The new patch is stored in persistent memory.
• Button B3 while options enabled enables or disables delay/envelope/filters for the current patch. The current setting is indicated by red LEDs. First two = delay enabled, middle two = envelope enabled, last two = filters enabled.

34: MI Clouds

• Button B1 browses to the previous patch (patches are defined in config file).
• Button B2 browses to the next patch.
• Button B4 selects the input source as usual.
• Button SET enables more options, press it once and orange LEDs will start blinking.
• Button B1 while options enabled browses through parameters, selecting the previous one. Indication will be added but for now you need to watch the debug console output over serial port to see what you are doing.
• Button B2 while options enabled browses through parameters, selecting the next one.
• Button B3 while options enabled decreases value of the currently selected parameter.
• Button B4 while options enabled increases value of the currently selected parameter.
• RST+B1 while options enabled decreases the limiter threshold.
• RST+B2 while options enabled increases the limiter threshold.

41: DCO (Digitally Controlled Oscillators)

• Sensors S1-S4 influence parameters in a chaotic way. This channel is still work in progress, so the current behaviour is likely to change a lot.

43: Filtered "Space" channel

• Sensor S1 controls delay as usual.
• Sensor S2 increases source noise intensity.
• Sensor S3 increases filters resonance.
• At the same time, sensors S1-S4 control individual low-pass filters.
• Button B1 increases the upper range for filters' cut-off point.
• Button B2 locks or unlocks effects (S1-S3). If locked, the sensors will not trigger effects, only influence filters' cut-off point.
• Buttons B3,B4 control fixed delay and inputs as usual.
• Button SET starts binaural beats. Press repeatedly to select one of the 4 programs.

44: Filtered "Space" channel with reverb

• Sensor S1 controls delay as usual.
• Sensor S2 increases source noise intensity.
• Sensor S3 increases filters resonance.
• Sensor S4 adds reverb effect.
• At the same time, sensors S1-S4 control individual low-pass filters.
• Button B1 increases the upper range for filters' cut-off point.
• Button B2 locks or unlocks effects (S1-S3). If locked, the sensors will not trigger effects, only influence filters' cut-off point.
• Buttons B3,B4 control fixed delay and inputs as usual.
• Button SET starts binaural beats. Press repeatedly to select one of the 4 programs.

111: Custom chord progression Fixed!

This channel waits for you to select how many chords you want to define. Initially ou can see 4 red and 2 orange LEDs glowing, that's 8 chords total. Use the buttons to change it, the range is from 1x1 to 8x4 chords. Confirm your selection with SET. Alternatively you can just start playing MIDI keyboard, then you don't need to specify number of chords up front (and there can be more than 32 chords). When done, press SET.

• Button B1 creates new chord (starting with c-major), or shifts it down by a semi-tone. You can press it repeatedly to get to the desired key.
• Button B2 similarly, creates new chord, or shifts it up by a semi-tone.
• Button B3 navigates the pointer to the next chord.
• Button B4 navigates the pointer to the previous chord.
• Button B1+B2 changes to minor chord and back. (Use B1 as a "shift" key: press B1, press B2, release B2, release B1).
• Button B1+B3 moves the middle note around, so you can create alternative chords too.
• Button B1+B4 moves the third note around, so you can create alternative chords too.
• Button SET finishes the process. If you see red & orange LEDs blinking, that means you have not defined enough chords - use B3/B4 to move around to find out where a chord is missing. If enough chords are defined, this will store the result into persistent memory at "slot 0", where the progression is accessible by other channels.
• Button RST cancels programming and exits the channel.

112: Load chord progression

Copies the chord progression from a selected slot in persistent memory to slot 0, to make it accessible by other channels. It waits for you to key in the "slot number". This can be 1-8 digits long, only consisting of digits 1 to 4 as there are only 4 buttons. If no chord progression exists at a given slot, you will see all red LEDs blinking. If a chord progression was found, you will see a short "progress bar" animation as it is being loaded to "slot 0".

• Buttons B1-B4 are used to key in the slot number.
• Button SET confirms your choice.
• Button RST cancels the operation.

113: Store chord progression

Copies the chord progression from slot 0 to another slot in persistent memory. It waits for you to key in the "slot number". This can be 1-8 digits long, only consisting of digits 1 to 4 as there are only 4 buttons. If a chord progression exists at the slot already, it will be overwritten.

• Buttons B1-B4 are used to key in the slot number.
• Button SET confirms your choice.
• Button RST cancels the operation.

114: Delete chord progression

Deletes the chord progression at a selected slot in persistent memory. It waits for you to key in the "slot number". This can be 1-8 digits long, only consisting of digits 1 to 4 as there are only 4 buttons. If no chord progression exists at a given slot, you will see all red LEDs blinking. If a chord progression was found, you will see a short "progress bar" animation as it is being deleted.

• Buttons B1-B4 are used to key in the slot number.
• Button SET confirms your choice.
• Button RST cancels the operation.

121: Simple drum kit

Sensors trigger four built-in drum samples. Sequencer and custom samples (loaded from SD) will be added later. (WIP).

123: Pass-through from microphones

Useful for recording of material to be used in other channels. To play back the recorded files use channel 2222 (or long press SET while idle).

• Holding button B3 decreases input levels.
• Holding button B4 increases input levels.
• Buttons B3,B4 control fixed delay and inputs as usual.

124: Pass-through from line-in

Useful for recording of material to be used in other channels. Works the same as channel 123 but selects the line input by default.

1111-1114: Play the custom chord progression

Runs the user programmed composition (if defined using channel 111 or loaded using 112) with soundscapes as in 1-4.

• Sensor S1 controls delay as usual.
• Sensor S2 lowers background sample mixing level.
• Sensor S3 increases filters resonance.
• Sensor S4 adds arpeggiator effect.
• Button B1 switches between high-pass and low-pass filtering (the default varies by channel).
• Button B2 generates new random chord progression.
• Buttons B3,B4 control fixed delay and inputs as usual.
• Button SET starts binaural beats. Press repeatedly to select one of the 4 programs.

2222: Play files recorded on SD card

Plays the last recording from SD card. You can navigate to previous/next recording using buttons 1 & 2. This channel is also accessible with a shortcut - long press SET while idle. Similarly, recording is started by long press SET while something is playing.

Settings and configuration

Sensors vs Accelerometer

• 3333: Use accelerometer instead of IR sensors.
• 4444: Use IR sensors again. This can also be changed using main menu (see the settings leaflet).

Reset back to defaults

• 4321: Should something not sound right and you are not sure what caused it, reset all settings to default (volumes, delays, inputs).

Test and service channels

Most of these channels output information over the serial port; if you plug Gecho to your PC, it will appear as a "virtual serial port" that you can interact with using PuTTY or similar terminal utility. Please check this thread for more info about the serial port settings.

• 3111: Memory info (useful for firmware debugging).
• 3112: Board serial number, also displayed with LEDs as a BCD number.
• 3113: Accelerometer test.
• 3114: Sensors test (for calibrating the firmware).
• 3121: MIDI In test (data).
• 3122: MIDI In test (hardware signals).
• 3123: MIDI Out test.
• 3124: Test all LEDs.
• 3131: Sync In test (digital hardware signals)
• 3132: Sync Out test (digital hardware signals)
• 3133: CV In test (analog hardware signals).
• 3134: CV Out test (analog hardware signals).
• 3141: SD Card info.
• 3142: SD Card speed test.
• 3143: SD Card files list.

Microphone bias level

Experimental feature. You probably do not need to adjust this. The effect of changing this voltage is a trade-off between sensitivity and ground noise level.

• 4441: Set microphone bias voltage to AVDD (typically 3.0V).
• 4442: Set microphone bias voltage to 2V.
• 4443: Set microphone bias voltage to 2.5V.

Firmware utilities

• 4111: Info about FLASH memory partition from which the current firmware runs.
• 4112: Display firmware version with LEDs as a BCD number.
• 4222: Write config to SD card.

The config file can be re-loaded using an option in service menu.

• 44112233: Load firmware update from SD card.
• 44223344: Load new config and samples from SD card (not handy for updating your unit if it is already programmed, but useful for new boards with blank FLASH, e.g. DIY builds from bare PCB). This requires "hashed" files to be stored in /factory subdirectory on the SD card (for example this config and preloaded samples). Hash is simply a SHA1 of the entire file contenct. If you just want to update the config (after editing it or when required for new firmware version), quicker method is to use the service menu.
• 44332211: Discard updates & revert to factory firmware.