This is maybe the one to many FV1 design. But, if you care to know how it works in more details please consider reading further.The idea of designing an effect based on the FV-1 chip came when I realised that many reverb effects are built around that chip. And this is due to the amount of DSP processing that is required to create pleasant reverbs.With this design I wanted to achieve a few things:loads of memory for many DSP algorithmsa single rotary encoder to scroll through all algorithmCV control over all parameters including sample rate of the DSPattenuverters on all inputswet/dry blend outputstereo signal pathDSP, memory and audio pathThe stereo input on the top left of the main schematic sheet is wired so that the Left signal is duplicated on the Right channel if nothing is connected. Right after the input a resistive divider and a band pass of the first order filters out DC, high frequencies and make the input levels to the DSP input requirements. At the DSP input the signal is forked to a couple of buffer to feed the dry/wet mixer on the other side while maintaining the high input impedance. The dry/wet mix is done by mean of a resitive divider and suming op-amp that uses a double wiper potentiometer to act on both channels at the same time. The mixed signal is raised back up to Eurorack level at the same time.The bank selection of the DSP works by looking through the pages of a 24LC32 chip. In order to increase the number of banks two chips are present on board. In order to address them sequentially a coded rotary encoder scrolls through the algorithm with its 3 least significant bits through the program selection pins of the DSP. While the most significant bit is used to toggle the address of the two 24LC32 chips. Thus, on half of the full encoder range the top memory is addressed while on the rest of the encoder range the second memory is addressed.Input CV scalingIn order to use CV inputs in place of the potentiometers, for which the DSP chip was initially designed, they have to be rescaled. The schematic above shows, from left to right, attenuverting of the CV, summing with common mode potentiometer and scaling to 0-3.3V range. The atennuverting makes interaction with modulation source easier by allowing a rescale and phase inversion of the input modulation. The common mode potentiometer allows to ajust the effect without modulation sources plugged-in, and offset the DC level of the modulation, when one is present.Power supplyThe power supply features three functions. It takes the input voltage from the Eurorack power connector (keyed, but not further protected, one just has to be careful). It creates 3.3V, in two rails for analog circuits (op-amp, filters) on one and digital circuits (DSP, memory, clock) on the other. Finally it creates a -10V reference that is used for scaling the common mode control the the Eurorack CV levels.Voltage controlled clock, with optional crystalThe sampling rate of the DSP is directly derived from the crystal resonating frequency. An algorithm can get low-fi properties that are interesting from modulating the sampling rate. Thus the option of a voltage controlled clock was added thanks to the LTC6990 chip to replace the crytal for which the Spin FV-1 was originally designed.EZ-USB FX2LP interface circuitFor the Spin ASM IDE to recognise the EZ-USB FX2LP and the module as being a dev-board, this 4066 based isolator allows the separation of the I2C bus of the module from that of the devboard. This makes the Spin software recognise first the EEPROM from the EZ-USB which uppon detection disables the isolation and allows reprogramming of the EEPROM that holds the alorithms.And with that we have covered the design of this Eurorack effect module.

This project about simple midi controller that work with software and hardware also work as macropad with cherry mx switch, the important part it's small and very flexible. Of course basic programing required here but don't worry everyone can learn.So i made this project to solve my problem for my synthesizer keyboard which do not have efficient shortcut button for changing sound and my live setup. And the idea came accidentally when i looking for midi controller product on the internet and i found some DIY midi controller based arduino. So i start digging more information about programming and PCB making for this project, i spend almost 3 months for this process, but very worthed.For midi controller you need gather some component :Arduino promicro 5v or promini (3.3v if you want battery powered, but you will need FTDI or similiar programer)6x 12mmx12mm push button switch,2x 10k RV07/RK07 potentiometer1x EC11 rotary encoder (optional)10x 10K ohm resistor for external pullup if needed (the rest just for spare, because the arduino library it self used internal pullup from arduino)3x 220 ohm resistor for RGB data line, TX pin and VCC pin to 3,5mm jack port for midi out (if used 3.3v pro mini you need 33ohm and 10ohm)1x PJ307 3.5mm TRS female socket1x MSS22D18 slide switch for powering arduino via battery6x WS2812B RGB led, and 6x 100nf 0805 and 1x 220ohm resistor capacitor if you want fancy featureIf it's just for macropad or shortcut button for windows or mac :Arduino promicro 32u4Cherry MX style switch1x EC11 rotary encoder (optional)6x WS2812B RGB led, and 6x 100nf 0805 and 1x 220ohm resistor if you want underglow feature3x6 SMD Tactile switch button for reset switchNOTE : I had two version gerber file for this project configuration, first PCB design support 1 encoder and 2 potentiometer, second PCB design support 3 potentiometer and does not support encoder. In this shared project for the first PCB design that support encoder, but If you need second PCB design just contact me or visit my youtube video demo for this project !Last, you must check the layout or component placement in the laser cut file there are for 2 design, and choose what design which suitable for your need i meant if you want rotary encoder you can placing order directly and if you need 3 potentiometer layout just contact me first.

Have you ever wanted to make your own guitar or musicall effect? This design is for you! It allows you to apply DSP algorithms to construct anything: overdrive, chorus, flanger, delay. You can even make a looper with maximum loop time related to your programming skills. Or maybe you want to make a module for audio system? You are welcome: PCB predicts the need of connecting 800x600 RGB screen. Additional connector allows you to connect I2C or SPI external sensor (e.g microphone).The heart of the project is STM32F7 MCU with external 128MBit RAM ang 1GBit FLASH. Audio signal can be gather with frequency up to 192 kHz with 24 bit resolution - quality far above studio devices. In the same time everything is very cost-effective. The whole board and assembly costs around 100$. You can release your imagination and apply your ideas in any form!