USB-I/O Interface Adapter GPIO-24. Programmer's Reference Manual.
4.4. GPIO_GET_DEV_ID (0x0E)
The GPIO_SET_CFG command configures settings for pins of a GPIO port with values from Bytes 4-7. The GPIO port is specified in Byte 2 .
GPIO_SET_CFG Command
| Byte 0 | GPIO_SET_CFG | Command ID (0x01). |
| Byte 1 | ECHO | Echo to associate a command with the response. |
| Byte 2 | PORT | GPIO port. |
| Byte 3 | MASK | Data mask to use when modifying I/O pin
configuration. |
| Byte 4 | PIN 7,6 | Configuration settings for 7, 6 pins. |
| Byte 5 | PIN 5,4 | Configuration settings for 5, 4 pins. |
| Byte 6 | PIN 3,2 | Configuration settings for 3, 2 pins. |
| Byte 7 | PIN 1,0 | Configuration settings for 1, 0 pins. |
Command is an 8-byte array of the following format:
- Byte 0: GPIO_SET_CFG (0x01)
This byte contains command ID (command type). It should be set to 0x01.
- Byte 1: ECHO
This byte can be 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 to configure:
0 – GPIO PORT A
1 – GPIO PORT B
2 – GPIO PORT C
- Byte 3: MASK
Data mask which is used to modify GPIO port 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. The pins with mask bit set to 0 will leave unchanged.
- Byte 4..7: PINS
Each nibble (four-bit aggregation or half an 8-bit byte) of bytes 4-7 contains configuration settings for a specific pin. The following values are supported:
GPIO_CFG_IN (0x0) – GPIO port is configured for input. GPIO-24 adapter can send events when input level is changed. Use GPIO_SET_IN_CFG command to configure event generation;
GPIO_CFG_OUT (0x1) – GPIO port is configured for output. Use GPIO_SET_OUT_VAL command to set output value;
GPIO_CFG_PWM (0x2) – GPIO port is configured for PWM (Pulse Width Modulation) output. Use GPIO_SET_PWM_CFG command to configure PWM setting;
GPIO_CFG_NOT_CONFIGURED (0xf) –
I/Oport is not configured.
For convenience GPIO_SET_CFG_CMD structure is declared in reports.h file.
GPIO-24 adapter sends GPIO_SET_CFG response after command execution.
GPIO_SET_CFG Response
| Byte 0 | GPIO_SET_CFG | Response ID (0x01). |
| Byte 1 | ECHO | Echo to associate a command with the response. |
| Byte 2 | ST | Command execution status. |
| Bytes 3..7 | Reserved | Reserved. |
Response is an 8-byte array of the following format:
- Byte 0: GPIO_SET_CFG (0x01)
Response ID (response type). This byte will contain 0x01.
- 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 GPIO port was successfully configured;
GPIO_ST_INVALID_PORT (0x03) – Invalid port number has been specified;
GPIO_ST_INVALID_CFG (0x04) – Invalid configuration value has been specified in one or more PINS nibbles. These pins were left with their previous configurations. The correct configuration values were applied for other pins.
- Bytes 3..7: Reserved
These bytes are reserved for future usage.
For convenience GPIO_SET_CFG_RSP structure is declared in reports.h file.
