[Openbts-discuss] Transceiver.cpp RX Failed to tune - RXTUNE failed with status 1

[Fabian U. <ma...@fa...>]

Hello!

I have an USRP1 with two RFX1800 daugtherboards.
GNURadio is running under Ubuntu Linux and seems to work (usrp_fft.py - 
R A -f 1724.4e6 shows me the spectrum).

I have the current revision of OpenBTS from the GNURadio subversion  
repository.
configure, make, make install seems to work fine.

I copied OpenBTS900.cpp to OpenBTS1800.cpp and edited the parameter of  
gBTS from EGSM900 to DCS1800
and changed the ARFCN to 583 (1724,4MHz and 1819,4MHz).
It compiles a OpenBTS1800 binary.

The problem is starting ./transceiver and then ./OpenBTS1800 the  
following errors occurs:
transceiver:
Transceiver.cpp:501: RX failed on tune

OpenBTS1800:
TRXManager.cpp:352: WARNING -- RXTUNE failed with status 1
TRXManager.cpp:396: WARNING -- POWERON failed with status 1

I found out that the problem is located in the function rx_setFreq  
(Transceiver/USRPDevice.cpp).

Transceiver/USRPDevice.cpp:

bool USRPDevice::rx_setFreq(double freq, double *actual_freq)
{
	unsigned R, control, N;
	if (!compute_regs(freq, &R, &control, &N, actual_freq)) return false;
	if (R==0) return false;

	m_uRx->_write_spi(0,SPI_ENABLE_RX_B,SPI_FMT_MSB | SPI_FMT_HDR_0,  
write_it((R & ~0x3) | 1));
	m_uRx->_write_spi(0,SPI_ENABLE_RX_B,SPI_FMT_MSB | SPI_FMT_HDR_0,  
write_it((control & ~0x3) | 0));
	usleep(10000);
	m_uRx->_write_spi(0,SPI_ENABLE_RX_B,SPI_FMT_MSB | SPI_FMT_HDR_0,  
write_it((N & ~0x3) | 2));

	if (m_uRx->read_io(1) & PLL_LOCK_DETECT)  return true;
	if (m_uRx->read_io(1) & PLL_LOCK_DETECT)  return true;
	return false;
}

It should return true, but it returns false in the last line of this  
function.
I make a printf so see the values of PLL_LOCK_DETECT and m_uRx- 
 >read_io(1).
m_uRx->read_io(1) = 0xff3b = 1111 1111 0011 1011
PLL_LOCK_DETECT = 0x4 =  0000 0000 0000 0100
-> so "if (m_uRx->read_io(1) & PLL_LOCK_DETECT)  return true;" is  
false and so it does not return true!

The value of "PLL_LOCK_DETECT" is right, so "m_uRx->read_io(1)" must  
have the wrong value.
The second bit must be 1 and not 0, so the function returns true.

Does anyone know what's wrong here?

Thanks & Regards
	-Fabian-