# dtmf_encoder_ht9200

HT9200 DTMF generator library

Author | Matthew Schinkel, copyright © 2009, all rights reserved.
Adapted-by |
Compiler | >=2.4o

Description

    Select a DTMF signal to be generated by HT9200.

Notes

    Sound is only generated while chip select is LOW

Dependencies

No dependency found

## Summary

### Global variables/contants

- `const byte hd9200_values[25] = {`

### Procedures

- `hd9200_digit(byte in digit, byte in length)`
- `hd9200_dial(byte in phone_numbers[], byte in length)`
- `hd9200_send(byte in digit)`

### Functions

## API details

### Global variables/contants

- `const byte hd9200_values[25] = {`

      Tone output frequency table
      Bits are reversed for LSB spi

### Procedures

- `hd9200_digit(byte in digit, byte in length)`

      Send via SPI with use of chip select lines.
      Length is how long the sound will play in 100ms.

- `hd9200_dial(byte in phone_numbers[], byte in length)`

      Send a string of numbers to output. Dial a phone number.
      length is how long the sound will play in 100ms.
      " " sends no sound.

- `hd9200_send(byte in digit)`

      Send via SPI without use of chip select lines.
      sound will play until chip select goes high.
      See hd9200_values[]

### Functions

## Related samples

Here are the list of samples which use this library:

18f4550 | 18f4550_dtmf_encoder_ht9200.jal