When making an ultrasonic musical instrument, I came to think that it would be better if various sounds could be output.
what is YMF-825
Yamaha FM sound source chip YMF825 (SD-1) It is a sound source board equipped with . Equipped with Yamaha’s original FM synthesizer, it is possible to reproduce rich sound by specifying several types of parameters.
Sound is produced by directly controlling the YMF825 register from a microcomputer board such as Arduino or Raspberry Pi through SPI. Since it also has a speaker amplifier, there is no need to prepare an amplifier circuit separately.
* Although it is equipped with a 3.5 mm headphone jack, earphones that use 4-pole CTIA such as for iPhone cannot be used (OMTP ones can be used). ** From Switch science’s sales page **
- 4 operator FM sound source
- Up to 16 sounds can be produced at the same time
- 29 types of FM basic waveforms built-in, 8 types of algorithms
- SPI Serial interface by
- Built-in speaker amplifier
- Built-in 3-band equalizer
- Built-in 16-bit monaural D / A converter
- Operating voltage: 5 V
- 3.3 V can also be used by modifying
A sample sketch is posted on GitHub, so I used it as a reference.
Any waveform can be created
The sample sketch also includes a simple manual.
Basic, sine wave, triangle wave, sawtooth wave, square wave, half wave rectified wave, etc.
7 types of return can be applied
You can also choose from seven types of return, which are familiar to effectors and synthesizers.
I don’t know the details yet, so I would like to introduce it in the future.
What is SPI Communication
The Serial Peripheral Interface (SPI) is a method of connecting devices used inside a computer, and is used for devices that perform relatively low-speed data transfer.
SPI is a standard proposed by Motorola (currently NXP Semiconductors) as a pin-saving bus.
The signal line consists of 4 lines, and when connecting one device, it can be connected with 3 lines by fixing the SS.
Master In Slave Out
Master Out Slave In
Simple operation circuit example
Next is the connection diagram.
Since YMF-825 and Arduino Nano are only communicated in SPI format, connect the power supply line (+ 5V, GND) and SPI terminal (SCK, MISO, MOSI, SS, Reset) to each other.
That’s all for today