struct sr_dev_inst *sdi;
struct dev_context *devc;
struct sr_serial_dev_inst *serial;
+ int rts_toggle_delay_us;
GSList *devices;
int ret;
uint8_t buf[128];
if (serial_open(serial, SERIAL_RDWR) != SR_OK)
return NULL;
+ /*
+ * The device requires an RTS *pulse* before communication.
+ * The vendor's documentation recommends the following sequence:
+ * Open the COM port, wait for 100ms, set RTS=1, wait for 100ms,
+ * set RTS=0, wait for 100ms, set RTS=1, configure bitrate and
+ * frame format, transmit request data, receive response data.
+ */
+ rts_toggle_delay_us = 100 * 1000; /* 100ms */
+ g_usleep(rts_toggle_delay_us);
+ serial_set_handshake(serial, 1, -1);
+ g_usleep(rts_toggle_delay_us);
+ serial_set_handshake(serial, 0, -1);
+ g_usleep(rts_toggle_delay_us);
+ serial_set_handshake(serial, 1, -1);
+ g_usleep(rts_toggle_delay_us);
sr_info("Probing port %s.", conn);
devices = NULL;
- conn = serialcomm = NULL;
+ /*
+ * BEWARE! Default 'conn' is not desirable when the device cannot
+ * reliably get detected. Insist that users specify the port.
+ */
+ conn = NULL;
+ serialcomm = "9600/8n1/dtr=1/rts=1";
for (l = options; l; l = l->next) {
src = l->data;
switch (src->key) {
if (!conn)
return NULL;
- if (serialcomm)
- devices = brymen_scan(di, conn, serialcomm);
- else
- devices = brymen_scan(di, conn, "9600/8n1/dtr=1/rts=1");
+ devices = brymen_scan(di, conn, serialcomm);
return devices;
}