RabbitCore eDisplay OP7200, Руководство пользователя

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eDisplay (OP7200)
The peripheral board sends back the character the master sent.
This function will
check device information
to determine that the peripheral board is connected to a master.
PARAMETERS
handle
is an address index to device information. Use
rn_device()
or
rn_find()
to establish the
handle.
sendecho
is the character to echo back.
recdata
is a pointer to the return address of the character from the device.
RETURN VALUE
The status byte from the previous command. -1 means that device information indicates the peripheral
board is not connected to the master.
Writes a string to the specified device and register. Waits for results.
This function will
check device infor-
mation to determine that the peripheral board is connected to a master.
PARAMETERS
handle is an address index to device information. Use rn_device() or rn_find() to establish the
handle.
regno
is the command register number as designated by each device.
data
is a pointer to the address of the string to write to the device.
datalen
is the number of bytes to write (0–15).
NOTE: A data length of 0 will transmit the one-byte command register number.
RETURN VALUE
The status byte from the previous command. -1 means that device information indicates the peripheral
board is not connected to the master, and -2 means that the data length was greater than 15.
SEE ALSO
rn_read
int rn_echo(int handle, char sendecho,
char *recdata);
int rn_write(int handle, int regno, char *data,
int datalen);