Connecting to GPS antenna

Hi, I don't know if this is the right section of the forum for this post?

I have read some where that you cannot connect a gps antenna to a UNO and a computer to the USB port of the UNO at the same time, is this true?

Also I have a Trimble antenna that I wish to use, would this be feasible to connect to the UNO?

Thank's in advance for any replies.

The GPS module generally uses serial communication. Presumably the Trimble is such a device. TheATmega328 has only one hardware UART which is usually dedicated to the USB interface.

You need to use a software serial (library) function to attach a second serial device such as a GPS - but it is doable.

A GPS antenna alone won't do anything! A GPS module on the otherhand communicates by a serial line so can be connected to any Arduino easily. However you do need to make sure the right supply voltage is provided to the GPS, if its 3.3V you will need a 3.3V regulator (the on-board 3.3V isn't powerful enough and also doesn't work without USB, which sounds like what you are worried about).

Yes the Trimble is serial, I was hope to link up to the computer to do some algorithms . May be via the UNO is not the way to go.

Just checked, I was wrong it has a co-axial connection.

The GPS antenna connects directly to the GPS module somehow. The GPS module also has a connection to the Arduino ( usually a serial connection ). The GPS antenna does not connect directly to any part of the Arduino.

Unless you actually need to Uno to perform some processing, you can just use a USB to TTL module to connect the GPS to the USB port of the computer.

The coaxial connection would be for the antenna. Are you sure you are not confusing an antenna with an actual GPS unit?

I do mean antenna, so do I need a unit in between antenna and PC

And this is why I'm so pedantic when it comes to electronics.

I think you need a GPS by the sound of it.

Sorry but I am more into programming than elactronics

The GPS modules that you can buy for around $30, there are several different brands.

The antenna for these is a chunky square thing about 18 mm square and about 8 mm thick. They are usually a pink color for some reason that is unknown to me. For most GPS modules, the antenna is glued directly on top of the GPS microchip. Some of them have a cable connection so you can put the antenna somewhere else.

The GPS module connects to the Arduino by a serial connection, normally 4 wires, +5V, ground, RX and TX. Some of them have the Rx and Tx incorrectly labelled.

Using a USB to serial converter, you can connect the GPS module directly to your computer and use one of several free applications to interact with it.

The antenna itself is of no use to you. You cannot connect the antenna to an Arduino. The Arduino has no RF processing capability. The antenna is only useful when connected to a GPS module.

Amongst my collection - here somewhere - is a GPS unit - complete, looks rather like the antenna only as nowadays they are usually integrated into one unit - which is on the end of a lead with a USB plug on the other end.

It sounds as if one of those would suit you - if the interface is documented and reasonably straightforward - connected directly to the PC/ laptop and with suitable software.

A GPS receiver, commonly called a GPS module these days (as they are now tiny), is an
extremely sophisticated piece of hardware that includes dozens of extremely sensitive
receiver circuits, significant compute power and highly precise hardware timers that
perform trilateration on the demodulated satellite signals to ns accuracy - without such a unit
a GPS antenna is entirely useless! Such units also incorporate significant ROM memory
holding a map that corrects for the lumpiness of the earth’s geoid so that altitiude
readings are accurate.

The square antennas are a slab of ceramic dielectric material that act as resonant
devices at the GPS signal frequency, normally called a “patch antenna”.