USB-I/O Interface Adapter GPIO-24. Programmer's Reference Manual.
4.10. GPIO_CLR_CFG_EEPROM (0x1C)
The GPIO_GET_VDD command allows to retrieve the GPIO-24 adapter supply voltage (VDD). The VDD can be either 3.3 V or 5.0 V. You can change the GPIO-24 adapter voltage by changing the JP3 jumper position on the GPIO-24 board. If JP3 is open the VDD equals to 5 V, otherwise it equals to 3,3 V.
GPIO_GET_VDD Command
| Byte 0 | GPIO_GET_VDD | Command ID (0x27). |
| Byte 1 | ECHO | Echo to associate a command with the response. |
| Bytes 2..7 | Reserved | Reserved (must be 0). |
Command is an 8-byte array of the following format:
- Byte 0: GPIO_GET_VDD (0x27)
This byte contains command ID (command type). It should be set to 0x27.
- 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.
- Bytes 2..7: Reserved
These bytes are reserved for future usage and must be set to 0.
For convenience GPIO_GET_VDD_CMD structure is declared in reports.h file.
GPIO-24 adapter sends GPIO_GET_VDD response after command execution. The GPIO-24 adapter supply voltage is specified inside the response.
GPIO_GET_VDD Response
| Byte 0 | GPIO_GET_VDD | Response ID (0x27). |
| Byte 1 | ECHO | Echo to associate a command with the response. |
| Byte 2 | ST | Command execution status. |
| Byte 3 | VDD | The supply voltage (VDD) value. |
| Bytes 4..7 | Reserved | Reserved |
Response is an 8-byte array of the following format:
- Byte 0: GPIO_GET_VDD (0x27)
Response ID (response type). This byte will contain 0x27.
- 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: ST
Status of the command execution:
GPIO_ST_SUCCESS (0x0) -The supply voltage (VDD) value has been retrieved.
- Byte 3: VDD
The supply voltage (VDD) value. The VDD can be either 3.3 V or 5.0 V. VDD value of 33 corresponds to 3.3 V. VDD value of 50 corresponds to 5.0 V.
- Bytes 4..7: Reserved
These bytes are reserved for future usage.
For convenience GPIO_GET_VDD_RSP structure is declared in reports.h file.
