On Sun, 4 Feb 2018, David Basden wrote:
This patch fixes a regression of rtl-sdr dongles with
the FC00012 tuner.
The code to switch on the FC00012 tuner by pulling it's ~RESET line
low ended up with an off-by-one error in a refactor a long time ago,
The FC00012 only continued to work by accident as a different bug in
rtlsdr_set_gpio_output had a side-effect of pulling low the FC00012's
~RESET line
When the rtl_set_gpio_output bug was fixed in ba64a7459a43 the side-
effect also went away, leaving the FC00012 tuner in reset, and failing
to be detected (or indeed work at all).
This patch fixes the original off-by-one error. It's been tested
on an FC00012 in a GTek T803 from both warm and cold starts, but needs testing on
the FC2580 as both the FC00012 and FC2580 are brought out of reset by a GPIO off the RTL
(at least in some
designs). If the FC2580 actually uses a different pin, this code will also break.
(I'm only going from vague memory that the FC2580 used the same pin.)
Hi David,
I ran into the same issue and already submitted a patch
http://lists.osmocom.org/pipermail/osmocom-sdr/2017-November/001630.html
but it seems nobody was interested in integrating it. I wasn't the first
to run into this either:
http://lists.osmocom.org/pipermail/osmocom-sdr/2017-October/001617.html
I see we reached the same conclusions and the patches are also very
similar. The one difference is that you also do:
@@ -1581,7 +1581,7 @@ int rtlsdr_open(rtlsdr_dev_t
**out_dev, uint32_t index)
reg = rtlsdr_i2c_read_reg(dev, FC0012_I2C_ADDR, FC0012_CHECK_ADDR);
if (reg == FC0012_CHECK_VAL) {
fprintf(stderr, "Found Fitipower FC0012 tuner\n");
- rtlsdr_set_gpio_output(dev, 6);
+ rtlsdr_set_gpio_output(dev, 5);
dev->tuner_type = RTLSDR_TUNER_FC0012;
goto found;
}
What is the purpose of this change? I see GPIO 6 is used in
fc0012_set_freq():
int fc0012_set_freq(void *dev, uint32_t freq) {
/* select V-band/U-band filter */
rtlsdr_set_gpio_bit(dev, 6, (freq > 300000000) ? 1 : 0);
return fc0012_set_params(dev, freq, 6000000);
}
so I think we need to set GPIO 6 to output mode.
Best regards,
David