What if I can't cold start positioning for a long time?
Then you need to check whether the GPS antenna placement position is in an open environment. Can you read the GPS data output by the GPS module? The GPS satellite signal status can be observed in the GSV statement in the GPS data. From these aspects, you can judge Where is the specific problem! The module can output once per second: $GPGGA $GPGSA $GPGSV $GPRMC positioning data, we usually use $GPRMC to streamline this data, this information contains the target: longitude, latitude, speed (nautical mile/hour), motion direction angle, year, month, hour, minute, second, millisecond, whether the positioning data is valid or invalid. Most of the GPS module chips use the world's first market share of SiRFIII. The main series, SiRFIII chip is 20 channels, real-time solution ability. This part of the module is very common on the market: Huan Tian, Da Gama, Ublox, etc.
What about antenna status monitoring?
When the antenna is short-circuited, what should be done? The best way is to use the GPS module to output the short-circuit status of the antenna to prompt the customer to do this check. This has the advantage that the customer can easily view the problem. At the same time, the protection module is not subject to high current impact. Many such applications on the market, such as S-87, S-90, S-93 and UBLOX, also have such functions, but the difference is that Ublox needs to take peripheral devices. To achieve this function, Da Gama does not need any peripheral devices, as if this function can only be implemented in the flash version, the rom version can not be configured with IO port, this function can not be achieved.