jbrzusto / librtlsdr Goto Github PK

some newer rtlsdr dongles include an antenna bias voltage.
e.g. here

This one is controlled by setting / clearing gpio 0 in librtlsdr.c:

int rtlsdr_set_bias_tee(rtlsdr_dev_t *dev, int on)
{
	if (!dev)
		return -1;

	rtlsdr_set_gpio_output(dev, 0);
	rtlsdr_set_gpio_bit(dev, 0, on);

	return 1;
}

and then adding a call to force it off from rtlsdr_close:

	// Turn off the bias tee
	//rtlsdr_set_gpio_output(dev, 0);
            rtlsdr_set_gpio_bit(dev, 0, 0);

Implementation for SG:

• add above call to librtlsdr
• add a command to set / clear in rtl_tcp
• add a param in jbrzusto/sensorgnome/master/rtlsdr.js:RTLSDR.prototype.rtltcpCmds
• add a default ('off') setting in defaultDeployment.txt

This has been useful in finding some other bugs, as it lets me fake a devStalled condition by
stepping the system clock 30 seconds into the future, but really, timeouts should use
CLOCK_MONOTONIC for exactly that reason!