Four Common Faults of GPS Positioning Module

The GPS positioning module we often refer to is called the user part. It receives and demodulates satellite broadcast C/A code signals like “radio”, with a frequency of 1575.42 MHz. The GPS module does not broadcast signals and is a passive location. By calculating the pseudo-distance with each satellite, the four parameters of the receiver's obtained longitude, latitude, altitude, and time correction are obtained by distance intersection method. The characteristics are that the point speed is fast, but the error is large. The first positioning module needs at least 4 satellites to participate in the calculation, called 3D positioning, 3 satellites can achieve 2D positioning, but the accuracy is not good. The GPS module continuously outputs the positioning information and auxiliary information in the NMEA format through the serial communication port for the receiver to select and apply.

The first major fault Fault: module did not work <br> <br> this case there is a lot of reason will appear, we must first measure the pin voltage, which is the easiest and most simple way to judge if there is voltage Abnormal, it is necessary to separately check whether it is a problem of the power supply circuit, or whether there is a short circuit when the module is soldered. If it is an unknown module, consider whether the internal short circuit is damaged, for example, if it is a sample of u-blox purchased from Feiyang Technology. , Anti-static packaging, do not have to consider these effects, but from the channel of the unknown source of the procurement of the module will have to consider whether it is possible, and so on, it also has to be considered as a focus.

In general, if you suspect quality problems, the possibility of formal agencies of branded components will be relatively small, but if you are buying products from the electronics market, you must first consider the situation of the source of goods. In this case, doing experiments is equivalent to Adding to the frost.

If it is a short-circuit situation, you can take the method of measuring the current. If it is not convenient to test the current, you must touch the bottom plate of the PCB to see if any component or module shows signs of heating. For the heat-generating part, analyze the possibility carefully.

During the welding process of u-blox products, there may be a phenomenon that the hand-welded module is short-circuited at the bottom but it cannot be observed with the naked eye. At this time, carefully use a universal meter to test whether there is a short circuit between two adjacent feet. In this case, the part will also generate heat. Of course, there must be no short circuit at the periphery. This time, the soldering iron should be used to reheat the part and re-apply the soldering flux for soldering. Sometimes there is a short circuit at the bottom. Soldering may be possible. Too much. At this time, it is necessary to remove the module from the bottom with a hot air gun and perform soldering on the removed module. Then re-welding again. All kinds of temperature control must be strictly controlled during welding. The maximum temperature of the module must not exceed 250 degrees. For 10 seconds, it must be remembered that all the operating procedures are correct, so that the damage rate of the module in the experiment is as low as possible.

In general, if the circuit itself is mature, it is important to consider the above mentioned short-circuit welding problem. If the voltage of each pin is correct after the change, in principle, the possibility of passing will be greater.

The second failure phenomenon: the module voltage is normal but there is no NMEA code output <br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br><br> Both are related to the TTL level circuit.

Third Symptom: NMEA output module has a normal voltage but no location information
<br> <br> this case very many cases, but the following cases are placed outside the test machine, the signal strength is not considered a problem.

If it is a passive antenna, pay attention to whether the peripheral circuit is correct when using outdoors. If you use an external active antenna, you must consider whether the RF[_]IN pin has a 3V supply voltage. If not, it is RF. Some 3V power supply circuits are not provided, focusing on checking the power supply section of the RF section.

The fourth Symptom: NMEA output module has a normal voltage can not correspond to
such a case the main consideration <br> <br> USB power supply terminal module is normal, DP + / DP- reverse data using a USB cable, There is also a situation where the protection tube is clamped or damaged. In case of emergency, the protection diode can be removed first to perform the communication operation, and then the specific experiment will be conducted later.

Standard function:

1.   Heat treated steel vertical  drill-resistant pins on both side of cylinder

2.   Mushroom counter pins resistant to attack.

5,6 rounded-head picking proof combination pins are available.

One side opened by key, one side is dead end.  

Optional function:

4.  Service key system: 1pcs, Once the owner's key be used, the  service key will be disabled.

5.  Stiffening device: Central breaking-proof, anti-snap, body reinforcement

6.  Owner card: As a indication of the key duplication and quality guarantee

7.   Master Key or Key Alike are available

8.   Finish:   01-Brass polished with varnish

                  02-Bright Nickel plated

                  03-Satin Nickel Plated

3430 category

Single Sided Computer Key Cylinder Lock

Single Sided Computer Key Cylinder Lock,Single Sided Cylinder Lock,Emergency Release Cylinder Lock,Single Lock Cylinder

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