Gecho v2 Channels

Firmware 1.0.113-115

• 1-4: Demo songs playing in the soundscapes from Glo. Press SET during play to start/stop binaural beats). Playable by MIDI (polyphonic).
• 11: The “channel 1” from the early prototype, it does not use controls, only microphones. You can boost the sensitivity using button 4 if needed.
• 12: Non-interactive, slowly evolving "Song of Wind and Ice" created using low-pass filters, with isochronic tones feature (press SET).
• 13: White noise
• 14: Bytebeat, a chiptune-like mathematically generated songs. Try buttons 1 (next song), 2 (panning), RST+1, RST+2 (speed control).
• 21-24: Run the user-programmed song (if present) with soundscapes as in 1-4.
• 31: Granular sampler. Use S2 to sample a new sound, S1 to detune, S3 to change chord, S4 to increase voices. Playable by MIDI (polyphonic).
• 32: Decaying reverb. Try buttons 1 & 2 to control decay direction and speed, S1 for delay, S3 for low-pass filter, S4 for reverb buffer length. Sound demo here and here.
• 33: Dekrispator (by Xavier Halgand). Buttons 1 & 2 browse patches, 3 sets filter/delay/env. RST+1/2 generate new patch & effects part separately. Sound demo here, it's from Glo but works and sounds the same in Gecho.
• 34: MI Clouds (by Émilie Gillet). Buttons 1 & 2 browse patches. S3 freezes the sound, then you can use MIDI to play it (monophonic).
• 41: DCO Synth with 24 oscillators. Press 1 repeatedly for parameters drift / randomize, 2 to set waveform, RST+1/2 for oversample control.
• 42: Sampled drum sequencer (WIP)
• 43: Space channel, without reverb (alternative fire element from Glo). Support binaural beats (press SET during play to start/stop this feature). Playable by MIDI (polyphonic).
• 44: Space channel, with reverb (fire element from Glo). Supports binaural beats (press SET during play to start/stop this feature). Playable by MIDI (polyphonic).
• 111: Program new chord progression using MIDI keyboard or buttons. The result will be stored in persistent memory at slot 0, accessible by other channels.
• 112: Copy the chord progression from a selected slot in persistent memory to slot 0, to make it accessible by other channels.
• 113: Copy the chord progression from slot 0 to another slot in persistent memory.
• 114: Delete the chord progression in a selected slot in persistent memory.
• 121: Simple drum kit. Sequencer and custom samples (loaded from SD) will be added later. (WIP).
• 123: Pass-through, useful for recording. You can choose inputs using button 4, as in any other channel. To play recorded files use channel 2222.
• 124: Pass-through, useful for recording. Same as 123 but selects line input by default.
• 2222: Play the last recording from SD card. You can navigate to previous/next recording using buttons 1 & 2. This is also accessible with a shortcut - long press SET while idle. Similarly, recording is started by long press SET while something is playing.
• 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.