https://github.com/kalmik/spiware

https://github.com/kalmik/spiware

arduino arduino-library arduino-uno firmware intel-galileo spi

Last synced: 16 days ago
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• Host: GitHub
• URL: https://github.com/kalmik/spiware
• Owner: kalmik
• Created: 2017-12-04T15:16:28.000Z (about 7 years ago)
• Default Branch: master
• Last Pushed: 2017-12-05T23:27:48.000Z (about 7 years ago)
• Last Synced: 2024-10-30T21:12:05.269Z (2 months ago)
• Topics: arduino, arduino-library, arduino-uno, firmware, intel-galileo, spi
• Language: C
• Size: 13.7 KB
• Stars: 0
• Watchers: 2
• Forks: 0
• Open Issues: 1
• Metadata Files:
  • Readme: README.md

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README

        
# SPIWARE

	The GPIO expander over SPI communication

## Protocol 0.1

It's is a implementation to a SPI "bridge slave mode" to ATMEGA328p.

### Protocol byte frame

|MODE|VALUE   |PORT ADDR                   |PIN ADDR                   |

|----|--------|----------------------------|---------------------------|

|SPI_B7|SPI_B6| SPI_B5 \| SPI_B4 \| SPI_B3 | SPI_B2 \| SPI_B1 \| SPI_B0|

* SPI_B7

    > It's is the access mode to the regiters LOW (0) to read and HIGH (1) to write

* SPI_B6

    > It's is the bit value to be write on register

* SPI_B[5-3]

    > Register address [ PORT | DDR ]

* SPI_B[2-0]

    > Register slot address

#### PORT mapping (ATMEGA328p only)

|REGISTER | ADDR|

|-----|-----|

|DDRB |0 0 1|

|DDRC |0 1 0|

|DDRD |0 1 1|

|PORTB|1 0 0|

|PORTC|1 0 1|

|PORTD|1 1 0|

#### Raw bit examples

* Write 1 on PB7

    ```c

    /*

     * We need to set

     * SPI_B7 = 1       --> Write mode

     * SPI_b6 = 1       --> write '1'

     * SPI_B[5-3] = 100 --> PORTB

     * SPI_B[2-0] = 111 --> 7 in binary

     */

    /* binary way */

    command = 0b11100111;

    /* hex way */

    command = 0xE7

    ```

* Read PD7

    ```c

    /*

     * We need to set

     * SPI_B7 = 0       --> Read mode

     * SPI_b6 = 0       --> 0

     * SPI_B[5-3] = 110 --> PORTD

     * SPI_B[2-0] = 110 --> 7 in binary

     */

     

    /* binary way */

    command = 0b00110110;

    /* hex way */

    command = 0x36;

    ```

 * Read ADC 1

 	To access the Analogic Digital Converter (ADC) the command should in READ MODE and set 1 in value bit (SPI_B6) and do not specify any PORT. so the command to read ADC should start with 01000_ _ _ the last 3 bits is the ADC number.

    ```c

    /* binary way */

    command = 0b01000001;

    // hex way

    command = 0x41;

    

    /*

     * To make easier you can do.

     */

     #define ANALOG_CMD = 0x40

     command = ANALOG_CMD | 0x01

    ```