Seeduino-Arch-Pro Ethernet

Page last updated 23 Jan 2015, by Devon Heron. 0 replies

In order to make the Seeduino-Arch-Pro successfully init the ethernet interface... you need to have a

extern "C" void mbed_mac_address(char *mac)

routine. So something like this to hard code a MAC address:

extern "C" void mbed_mac_address(char *mac){
  mac[0] = 0x00; mac[1] = 0x02; mac[2] = 0xF7; mac[3] = 0xF1; mac[4] = 0x91; mac[5] = 0x9F; 
};

or something dynamic based on serial number of the NXP chip:

extern "C" void mbed_mac_address(char *mac)
{
    static char buf[64] = {0};
    IAP iap;
    int32_t *block = iap.read_serial();
    uint32_t serial_number[5] = {0};
    
    memset(buf, 0, sizeof(buf));
    serial_number[0] = *(block);
    serial_number[1] = *(block+1);
    // we only want bottom 16 bits of word1 (MAC bits 32-47)
    // and bit 9 forced to 1, bit 8 forced to 0
    // Locally administered MAC, reduced conflicts
    // http://en.wikipedia.org/wiki/MAC_address
    //serial_number[0] |= 0x00000200;
    //serial_number[0] &= 0x0000FEFF;
    memcpy(mac, (uint8_t*) &serial_number[0], 6);
    mac[0] |= 0x02;
    mac[0] &= 0xFE;
    mac[5] |= 0x02;
    mac[5] &= 0xFE;
     
    snprintf(buf, 16, "%4X%08X", serial_number[0], serial_number[1]);
}

not sure that final snprintf command is necessary.

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