Hi all, I write a small function to modify the uart baud rate at the setup of the link between the stack bluez and the chip bluetooth. This function is highly inspired from functions in the hciattach.c file thanks to marcel. This function is specific to the development kit of Semtech-Xemics based on the SX1441 (bluetooth v1.2). I don't know if that can be usefull but I send you the output of the "diff" command between the original hciattach.c and thus modified. regards. Michel ------------------ output of the diff command -------------------------------- 804a805,900 > > > > > > /* > * Specific initialization for semtech-xemics > * development kit based on the SX1441 Bluetooth v1.2 > * > */ > static int xemics(int fd, struct uart_t *u, struct termios *ti) > { > struct timespec tm = {0, 50000}; > char cmd[13]; > > > > cmd[0] = HCI_COMMAND_PKT; > cmd[1] = 0x0b; // OCF = Hci_Cmd_xemics_Set_Uart_Baud_Rate > cmd[2] = 0xfc; // OGF = Vendor specific > cmd[3] = 0x09; > cmd[4] = 0x08; > cmd[5] = 0x02; > cmd[6] = 0x00; > > > > /* Xemics set baud rate command */ > /* BaudRate cmd[7]---cmd[10] > /* 115200 = 0x01C200 > 230400 = 0x038400 > 460800 = 0x070800 > 921600 = 0x0E1000 > > Important : cmd[7] = LSB first */ > > > switch (u->speed) { > > case 115200: > cmd[7] = 0x00 ; > cmd[8] = 0xC2; > cmd[9] = 0x01; > cmd[10] = 0x00 ; > > break; > case 230400: > cmd[7] = 0x00 ; > cmd[8] = 0x84; > cmd[9] = 0x03; > cmd[10] = 0x00 ; > break; > case 460800: > cmd[7] = 0x00; > cmd[8] = 0x08; > cmd[9] = 0x07; > cmd[10] = 0x00; > break; > case 921600: > cmd[7] = 0x00; > cmd[8] = 0x10; > cmd[9] = 0x0E; > cmd[10] = 0x00 ; > break; > default: > cmd[7] = 0x00 ; > cmd[8] = 0xC2; > cmd[9] = 0x01; > cmd[10] = 0x00 ; > > u->speed = 115200; > break; > } > > > cmd[11] = 0xb1; > cmd[12] = 0x03; > > > /* Send uart rate */ > if (write(fd, cmd, 13) != 13) { > perror("Can't write reset cmd."); > return -1; > } > > nanosleep(&tm, NULL); > > > > > return 0; > } > > > > 857a954,957 > /* Semtech Xemics development kit based on the SX1441 (bluetooth chip v1.2) */ > { "xemics", 0x0000, 0x0000, HCI_UART_H4, 115200, 115200, FLOW_CTL , xemics }, > >