uRock @ Jserv Course Final
- 1. uRock Music On MCU by Sonicyang Anarchih KK Hirokiht
- 2. Outline ● Project Target ● Circuit Design ● How community helped us ● How Effect works and Implementation ● Wav Playing and Recoder ● UI ● Challanges & Obstacles ● Housing
- 3. Project Target - Inspiration At the beginning, we want to try out audio signal processing on microcontrollers, insteads of traditional method, DSPs. As we are Guitar players, the Product we choose is Guitar Effect Pedal.
- 4. What is Effect Pedal
- 5. Circuit Design On our Design we want most of the work done digitally. The analog Circuit mainly contains some amplifiers and voltage regulators only.
- 6. Amplifiers and Level Shifters
- 7. Voltages Regulators The on board Switching regulators are noisy, thus we use external voltage regulators. ● We are using TI’s TPS7A4700, RF Rating Through, QFN20 is hard to solder, the result is Outstanding.
- 8. How Communities helped us Libraries and Firmware we are using ● STM32 Cube ● FATFS ● uGFX ● ARM DSP Lib OSS and sharing have make our way to the goal much more easier
- 9. STM32 Cube New HAL Firmware means fewer bugs. Handy STM32 Cube MX software, Generate Hardware related Initializing code. Comes with multiple Middlewares. ● FreeRTOS ● FATFS
- 10. uGFX Ported to base on Cube Firmware and FreeRTOS Very Flexible and portable, eased our pain on UI designing.
- 11. ARM DSP Lib Utiliztiing ARM’s SIMD instructions to speed up signal processing. support Fix point and floating point, but SIMD is only available to fix point numbers.
- 12. Effect ● Distortion ● Overdrive ● Equalizer ● Compressor ● Delay ● Reverb
- 13. For coding the effects, we use the ARM DSP Library to help us. We also use Q12 numbers(fix points) to enable the possibility to use ARM Cortex-M4F DSP & SIMD By using the Above 2 technicals, the speed gain is LARGE.
- 14. Aid of Python and MATLAB To simulate the Effects and visualize before hands. we use python and MATLAB to test the algorithms.
- 15. Effect - Overdrive & Distortion
- 17. Effect - Delay The internal SRAM is not deep enough, thus we store the delay data on external SDRAM.
- 18. Effect - Equalizer Use IIR Filter to filter the audio. Coefficient designing base on MATLAB’s aid.
- 19. Wav Player and Recorder Implemented Wav player and Recoder which plays 16bits 44100k files The purpose is to let user recode clips to accompany himself playings
- 20. UI
- 21. Challange & Obstacles 1. HAL Firmware is still new, lots libraries are still not compatiable. 2. Efficiently process audio siginals and preserve accuracy 3. The Digital Siginal Processing requires lost of MATH and base knowledge
- 22. Housing