Mikroelektronika MIKROE-442 Datenbogen

mikroBasic PRO for dsPIC30/33 and PIC24

MikroElektronika

491

SPI_Ethernet_initDHCP

sub function SPI_Ethernet_initDHCP(dim tmax as byte) as byte 

Description This is DHCP module routine. It sends an DHCP request for network parameters (IP, gateway, DNS 

addresses and IP subnet mask) and waits for DHCP reply. If the requested parameters were obtained 

successfully, their values are stored into the library global variables.

These parameters can be fetched by using appropriate library IP get routines:

- SPI_Ethernet_getIpAddress - fetch IP address. 

- SPI_Ethernet_getGwIpAddress - fetch gateway IP address. 

- SPI_Ethernet_getDnsIpAddress - fetch DNS IP address. 

- SPI_Ethernet_getIpMask - fetch IP subnet mask. 

UDP port 

68

 is used as DHCP client port and UDP port 

67

 is used as DHCP server port.

Parameters - 

tmax

: time in seconds to wait for an reply. 

- 

1

 - network parameters were obtained successfully. 

- 

0

 - otherwise. 

Ethernet module has to be initialized. See SPI_Ethernet_Init.

... 

  SPI_Ethernet_initDHCP(5) ‘ get network configuration from DHCP server, wait 

  ...

The Ethernet services are not stopped while this routine waits for DNS reply. The incoming packets will 

be processed normaly during this time.

When DHCP module is used, global library variable 

SPI_Ethernet_userTimerSec

 is used to keep 

track of time. It is user responsibility to increment this variable each second in it’s code.

SPI_Ethernet_doDHCPLeaseTime

sub function SPI_Ethernet_doDHCPLeaseTime() as byte 

Description This is DHCP module routine. It takes care of IP address lease time by decrementing the global lease 

time library counter. When this time expires, it’s time to contact DHCP server and renew the lease.

Parameters None.
Returns

- 

0

 - lease time has not expired yet. 

- 

1

 - lease time has expired, it’s time to renew it. 

Ethernet module has to be initialized. See SPI_Ethernet_Init.

while true

  ...

  if(SPI_Ethernet_doDHCPLeaseTime() <> 0) then

    ... ‘ it’s time to renew the IP address lease                  

None.