Hi! Motorola Droid 4 runs packet protocol over serial... and its kernel driver requires explicit "write()" boundaries at places where packet boundaries should be. So I can send SMS using low level g_at... functions (that are not normally accessible), but not using g_at_chat_send(). If anyone has good idea for clean (or clean enough) solution, let me know. Best regards, Pavel snprintf(buf, sizeof(buf), "AT+GCMGS=\r"); encode_hex_own_buf(pdu, pdu_len, 0, buf_pdu); #if WANT_IT_BROKEN strcat(buf, buf_pdu+2); g_at_chat_send(data->send_chat, buf, none_prefix, NULL, data, NULL); #else g_at_io_write(data->send_chat->parent->io, buf, strlen(buf)); g_at_io_write(data->send_chat->parent->io, buf_pdu, strlen(buf_pdu)); g_io_channel_flush(data->send_chat->parent->io->channel, NULL); #endif -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html