75+6628Q GPS 搜不到星
时间:10-02
整理:3721RD
点击:
问题如题
开gps,然后到工程模式里的YGPS项,启动NMEA的Log,有NMEA数据在跑。数据如下
$GPACCURACY,173205088.0*0A
$GPGGA,001004.000,8960.0000,N,00000.0000,E,0,0,,137.0,M,13.0,M,,*46
$GPGSA,A,1,,,,,,,,,,,,,99.99,99.99,99.99*30
$GPRMC,001004.000,V,8960.0000,N,00000.0000,E,0.000,0.00,060180,,N*67
$GPVTG,0.00,T,,M,0.000,N,0.000,K,N*32
$GPACCURACY,173205088.0*0A
$GPGGA,001005.000,8960.0000,N,00000.0000,E,0,0,,137.0,M,13.0,M,,*47
$GPGSA,A,1,,,,,,,,,,,,,99.99,99.99,99.99*30
$GPRMC,001005.000,V,8960.0000,N,00000.0000,E,0.000,0.00,060180,,N*66
$GPVTG,0.00,T,,M,0.000,N,0.000,K,N*32
$GPACCURACY,173205088.0*0A
$GPGGA,001006.000,8960.0000,N,00000.0000,E,0,0,,137.0,M,13.0,M,,*44
$GPGSA,A,1,,,,,,,,,,,,,99.99,99.99,99.99*30
$GPRMC,001006.000,V,8960.0000,N,00000.0000,E,0.000,0.00,060180,,N*65
$GPVTG,0.00,T,,M,0.000,N,0.000,K,N*32
$GPACCURACY,173205088.0*0A
不知道什么问题,要怎么查GPS 是否已经工作
开gps,然后到工程模式里的YGPS项,启动NMEA的Log,有NMEA数据在跑。数据如下
$GPACCURACY,173205088.0*0A
$GPGGA,001004.000,8960.0000,N,00000.0000,E,0,0,,137.0,M,13.0,M,,*46
$GPGSA,A,1,,,,,,,,,,,,,99.99,99.99,99.99*30
$GPRMC,001004.000,V,8960.0000,N,00000.0000,E,0.000,0.00,060180,,N*67
$GPVTG,0.00,T,,M,0.000,N,0.000,K,N*32
$GPACCURACY,173205088.0*0A
$GPGGA,001005.000,8960.0000,N,00000.0000,E,0,0,,137.0,M,13.0,M,,*47
$GPGSA,A,1,,,,,,,,,,,,,99.99,99.99,99.99*30
$GPRMC,001005.000,V,8960.0000,N,00000.0000,E,0.000,0.00,060180,,N*66
$GPVTG,0.00,T,,M,0.000,N,0.000,K,N*32
$GPACCURACY,173205088.0*0A
$GPGGA,001006.000,8960.0000,N,00000.0000,E,0,0,,137.0,M,13.0,M,,*44
$GPGSA,A,1,,,,,,,,,,,,,99.99,99.99,99.99*30
$GPRMC,001006.000,V,8960.0000,N,00000.0000,E,0.000,0.00,060180,,N*65
$GPVTG,0.00,T,,M,0.000,N,0.000,K,N*32
$GPACCURACY,173205088.0*0A
不知道什么问题,要怎么查GPS 是否已经工作
用meta 测cw,开始CNR只有35左右,后来发现lna那颗芯片虚焊,改好后可以到58,有时能上60多,可以pass了,但是那个 clock drift 还是-18.8 ppb,满足不了2.0的要求。我们那颗晶振规格是2.0ppm的,理论应该不会这么大才对啊,会不会是meta量出来的不准?还是晶振有问题?
换0.5PPM的试一下
而且软件上要对应修改这个PPM才行。
能否确认软件是对的?
搜一下这个 stGPSConfigDefault
然后将这个贴出来看看。
{
{'/','d','e','v','/','s','t','p','g','p','s',0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0,0x0},
1,
2600000000,
#if defined MTK_GPS_MT6628
2000
#else
500
#endif
0xff,
0,
0
};
#if defined MTK_GPS_MT6628
2000
#else
500
#endif
这个如果是2.0 PPM就都写成2000
如果是0.5PPM就都写成500
然后要NEW一下。
试试看看
我们的是2.0的,0.5的还没换到。
不知道用meta ->gps->cw test里测的是准确的吗?怎么有18.8的ppm这么大
换了个射频rf 用的晶振,测出来ppm6.0
我们没有测试过。
