Help with Arduino GPS module - Page 1
Forum section: electronics / rf-microwave

author: kuzm1nsk1
author_rank: Contributor
timestamp: February 10, 2024, 09:50:33 pm
content: Hello, can someone share their experience using NEO6M GPS module for Arduino? I'm building Arduino GPS clock as my final project so I bought NEO6M module hoping to use GPS signals for accurate time. I'm using module on the second picture and cannot get it to work. Every example I load, it says that there is no GPS signal or connection. It was showing time briefly in the beginning but then it stopped again. LED on the module is not blinking but lights up all the time. Searching the internet, I concluded that it must flash in order to work. It may be because it is located inside the house but that's the whole point. I don't want a clock that would have to be in the open field to receive GPS signal in order to work. It may be because of a small antenna, but who knows. I ordered new one with bigger antenna (picture 1) so maybe that solves the problem. Could bigger antenna solve the whole problem? Is there a way to test that module is working correctly and it's just because of a weak GPS signal? I could use NTP server or DCF77 to set the clock but I would really love it to work with GPS.

author: Peabody
author_rank: Super Contributor
timestamp: February 10, 2024, 10:03:44 pm
content: If you connect only power, ground, and the antenna to the module, it should start blinking if reception is good enough. But it may take a couple minutes or longer. Just be sure you're feeding it the right voltage for power (5V or 3.3V).Edit: You could also do that test outside. If it still doesn't work, something may be wrong with it.

author: Kean
author_rank: Unknown
timestamp: February 10, 2024, 10:23:42 pm
content: It should still be outputting serial data at 9600 baud even if it cannot get a good (or any) satellite fix. But a tiny antenna and a cheap GPS will not generally perform well indoors.The time & date can be reported with minimal satellite reception, so that should be output (possibly wrong at first) as part of the default serial data even without a blinking LED. The blinking LED indicates a position fix.You will likely need to locate the antenna close to a window to get some satellite reception, depending on the type of building you are in. Taking it outside for a few minutes running on battery power will help it download initial ephemeris data. Then when you go back inside it will hopefully still be able to maintain enough reception to track some satellites, or at least maintain accurate time.

author: Solder_Junkie
author_rank: Frequent Contributor
timestamp: February 11, 2024, 10:49:58 am
content: I have one of those modules, see attached, it came from eBay and cost around 7 euros. Note the micro USB socket adjacent to the SMA antenna socket.They are very insensitive with the included antenna. I notice that your module does not include a USB socket, so you cannot see what is happening with it unless you wire it to one. You will not get it working with that antenna indoors, unless you use at least a "hockey puck" amplified magnetic mount antenna near a window. It will work if you take it outdoors where it has a clear view of the sky.The free Ublox U-Center configuration software runs on a PC (or laptop) and allows you to configure the module via USB. It even works with the many fakes found on eBay.https://www.u-blox.com/en/product/u-centerSee alsohttps://www.qsl.net/g4aon/gpsdo/SJ

author: kuzm1nsk1
author_rank: Contributor
timestamp: February 11, 2024, 01:41:12 pm
content: Update: I was playing with it for a few minutes outside and LED started blinking. After loading tinygps or tinygps++ example I noticed that it only receives chars and doesn't wanna display anything else.

author: kuzm1nsk1
author_rank: Contributor
timestamp: February 11, 2024, 01:56:08 pm
content: Quote from: Solder_Junkie on February 11, 2024, 10:49:58 amI will be ordering GPS/GNSS module to test it's performance. How much difference would it make when you change a ceramic antenna with an active antenna, they are both for GPS of course?GPS/GNSS module:https://soldered.com/product/gnss-gps-l86-m33-breakout-with-easyc/Ceramic GPS antenna:https://soldered.com/product/ceramic-gps-antenna-1575-42mhz-with-ipx-connector/Active GPS antenna:https://soldered.com/product/active-gps-antenna-sma-connector/

author: kuzm1nsk1
author_rank: Contributor
timestamp: February 11, 2024, 02:31:28 pm
content: Update 2: After reading through forums someone said that NEO6M uses 9600 baud rate instead of 4800. Changed it and it works now.

author: Solder_Junkie
author_rank: Frequent Contributor
timestamp: February 11, 2024, 02:57:11 pm
content: Quote from: kuzm1nsk1 on February 11, 2024, 01:56:08 pmIt makes a huge difference, the amplified active antennas have 30 dB, or more, gain. You still need to place the antenna where it “sees” a good view of the sky. I have an outdoor “mushroom” antenna from Leo Bodnar:https://www.leobodnar.com/SJ

author: kuzm1nsk1
author_rank: Contributor
timestamp: February 11, 2024, 10:20:41 pm
content: Are this modules even capable of powering active antennas or do you have to connect some power supply that would power it through RF choke?

author: Solder_Junkie
author_rank: Frequent Contributor
timestamp: February 11, 2024, 11:54:36 pm
content: I don’t know about the module you are using. The ones I use have power out via the SMA socket to power an active antenna. I have 3 of these (as shown in reply #3) and they all work with both a magnetic mount “hockey puck” vehicle antenna, and a fixed “mushroom” timing antenna. I have replaced one of the Chinese fake Ublox Neo-M8N modules with a genuine M8T, but that is expensive and not an easy job to swap.SJ

author: kuzm1nsk1
author_rank: Contributor
timestamp: February 12, 2024, 09:16:43 am
content: I was watching IMSAI guy video about patch antennas (like the one shown in the first post) and when he dissasembled one there vas actually LNA in it. Searching the google I found out that this antennas exist in passive and active form but they look exactly the same. Is there a way to test if it’s active without dissasembeling it.Link to video:https://youtu.be/s-jFprdDcM4?si=Sq2Z6_2y6rPoGUd2

author: Ian.M
author_rank: Super Contributor
timestamp: February 12, 2024, 11:52:29 am
content: The video showed the LNA used isMAX2659and its datasheet shows nom 4.1mA supply current. Other LNAs are likely to have similar supply currents, so hook the antenna up to a power source of the correct voltage via a milliammeter and see if the current is 'in the ballpark' for an active antenna. Passive patch antennas are almost certainly open circuit to DC.