diff options
Diffstat (limited to 'src/lib.rs')
| -rw-r--r-- | src/lib.rs | 44 |
1 files changed, 41 insertions, 3 deletions
@@ -28,10 +28,17 @@ const KNOWN_DEVICES: [(u16, u16, &str); 2] = [ (0x0bda, 0x2838, "Generic RTL2832U OEM") ]; +const FIR_LENGTH: usize = 16; +const FIR_DEFAULT: [i16; FIR_LENGTH] = [ + -54, -36, -41, -40, -32, -14, 14, 53, // 8 bit signed + 101, 156, 215, 273, 327, 372, 404, 421 // 12 bit signed +]; + pub struct RtlSdr<'a> { ctx: &'a libusb::Context, dev: Option<libusb::DeviceHandle<'a>>, - iface_id: u8 + iface_id: u8, + fir: [i16; FIR_LENGTH] } impl<'a> RtlSdr<'a> { @@ -40,7 +47,8 @@ impl<'a> RtlSdr<'a> { RtlSdr { ctx, dev: None, - iface_id: INTERFACE_ID + iface_id: INTERFACE_ID, + fir: FIR_DEFAULT } } @@ -91,6 +99,36 @@ impl<'a> RtlSdr<'a> { self.demod_read_reg(handle, 0x0a, 0x01, 1) } + fn set_fir(&self, handle: &libusb::DeviceHandle) { + let fir: [i16; 20]; + + /* format: int8_t[8] */ + for i in 0..8 { + let val = FIR_DEFAULT[i]; + if val < -128 || val > 127 { + return; + } + fir[i] = val; + } + + /* format: int12_t[8] */ + for idx in 0..4 { + let i = idx * 2; + let val0 = FIR_DEFAULT[8+i]; + let val1 = FIR_DEFAULT[8+i+1]; + if val0 < -2048 || val0 > 2047 || val1 < -2048 || val1 > 2047 { + return; + } + fir[8+i*3/2] = val0 >> 4; + fir[8+i*3/2+1] = (val0 << 4) | ((val1 >> 8) & 0x0f); + fir[8+i*3/2+2] = val1; + } + + for i in 0..20 { + self.demod_write_reg(handle, 1, 0x1c + i, fir[i], 1); + } + } + fn init_baseband(&self, handle: &libusb::DeviceHandle) { // init USB self.write_reg(&handle, BLOCK_USBB, ADDR_USB_SYSCTL, 0x09, 1); @@ -114,7 +152,7 @@ impl<'a> RtlSdr<'a> { self.demod_write_reg(&handle, 1, 0x16 + i, 0x00, 1); } - // rtlsdr_set_fir(&handle); + self.set_fir(&handle); // enable SDR mode, disable DAGC (bit 5) self.demod_write_reg(&handle, 0, 0x19, 0x05, 1); |