USB-I/O Interface Adapter GPIO-24. Programmer's Reference Manual.

Command is an 8-byte array of the following format:

Byte 0: GPIO_SET_IN_CFG (0x05)

This byte contains command ID (command type). It should be set to 0x05.

Byte 1: ECHO

This byte is used to associate a response received from GPIO-24 adapter with a specific command. Response will contain exactly the same value in its echo byte.

Byte 2: PORT

GPIO PORT:

• 0 – GPIO PORT A

• 1 – GPIO PORT B

• 2 – GPIO PORT C

Byte 3: MASK

Data mask to use while modifying I/O pin digital input mode configuration. It is well known that a byte consists of 8 bits (which can be 0 or 1). This characteristic is used to create a mask. The mask value allows to modify certain pins, leaving rest of the pins unchanged. Note, that only the pins with mask bit set to 1 will be affected.

Byte 4: PHASE

Phase configuration, which determines the conditions when GPIO-24 adapter sends GPIO_EV_IN event.

The following values are available for this byte:

• GPIO_IN_EV_NONE (0x00) – No events are sent for current pin. For more detailed information see Section 6.2.1, “GPIO_IN_EV_NONE (0x00) – No events are sent”.

• GPIO_IN_EV_LEV_0 (0x01) – Events are sent when pin has logical "0" on its input. For more detailed information see Section 6.2.2, “GPIO_IN_EV_LEV_0 (0x01) – Sending events when pin has logical "0" on its input”.

• GPIO_IN_EV_LEV_1 (0x02) – Events are sent when pin has logical "1" on its input. For more detailed information see Section 6.2.3, “GPIO_IN_EV_LEV_1 (0x01) – Sending events when pin has logical "1" on its input”.

• GPIO_IN_EV_RISING (0x03) – Events are sent when input value changes from logical "0" to "1". For more detailed information see Section 6.2.4, “GPIO_IN_EV_RISING (0x03) – Sending events when input value changes from logical "0" to "1"”.

• GPIO_IN_EV_FALLING (0x04) – Events are sent when input value changes from logical "1" to "0". For more detailed information see Section 6.2.5, “GPIO_IN_EV_FALLING (0x04) – Sending events when input value changes from logical "1" to "0"”.

• GPIO_IN_EV_CHANGE (0x05) – Events are sent when input value of the pin changes. For more detailed information see Section 6.2.6, “GPIO_IN_EV_CHANGE (0x05) – Sending events when input value of the pin changes”.

Byte 5: DEBOUNCE

To avoid sending numerous events caused by contact bounce, GPIO-24 adapter accepts signal change only after the new value is stable. Byte 5: DEBOUNCE parameter specifies the debounce time in ms. If Byte 5: DEBOUNCE = 0, the debounce check is not carried out.

Byte 6: REPEAT

Byte 6 defines the repeat interval in units of 100 ms for the event GPIO_EV_IN generation. Byte 6: REPEAT is used for pins with phase configuration set to GPIO_IN_EV_LEV_0 or GPIO_IN_EV_LEV_1. It is ignored for pins with other phase configurations. If Byte 6: REPEAT is non-zero , GPIO-24 adapter sends events each REPEAT*100 ms. For more detailed information see Section 6.1, “Digital Input Event”.

Byte 7: Reserved

This byte is reserved for future usage and must be set to 0.

Response is an 8-byte array of the following format:

Byte 0: GPIO_SET_IN_CFG (0x05)

Response ID (response type). This byte will contain 0x05.

Byte 1: ECHO

Echo byte copied from the corresponding command. It is used to associate the response with the specific command.

Byte 2: ST

Status of the command execution:

• GPIO_ST_SUCCESS (0x00) – The I/O pins were successfully configured.

• GPIO_ST_INVALID_PORT (0x03) – Invalid port number has been specified.

Bytes 3..7: Reserved

These bytes are reserved for future usage.