GPS Modules with Arduino and Raspberry Pi

Posted by: @ronalex4203

@will Yes, first thing I tried.

I knew you'd say that, but you know that it had to be asked 🙂

I should add, I am inside but only a few feet from a big window. I understand poor reception, but absolutely nothing is a stretch. I might be able to move the test rig outdoors, I will try that in a few minutes just in case but I am not optimistic.

I've never used one but it seems like an odd error message if it just can't find enough sources.

If you have access to the source, try looking up the message you get and tracing it backwards in the code to find out what it thinks is wrong. That may give you a better starting place for debugging.

Have you already checked out 

https://github.com/StuartsProjects/GPSTutorial

@ronalex4203 

Other common problems seem to be (copied from another source) ...

The most common error is connecting TX to TX. TX on the GPS side should be connected to RX on the Arduino side. This problem is exacerbated by the fact that some devices are labeled in reverse. Try both orientations.

Next most common error is incorrect baud rate. Most common these days is 9600; check your device specs. The examples mostly default to 4800, so these should be changed.

Another common error when using SoftwareSerial is switching the TX and RX in the constructor. The RX pin goes first. SoftwareSerial ss(RXPIN, TXPIN);

The first thing I do when things go amiss for me is make sure I'm getting sort-of human readable text from the GPS. This is usually just a matter of writing a simple loop like this:

while (true)
{
if (ss.available())
Serial.write(ss.read());
}

If this shows nothing, your wiring is probably wrong. If it shows garbage, either your baud rate is wrong or your device is configured to binary mode.

@will I went outside and still nothing. I just reversed the TX, RX again and I am seeing data now. It isn't anything the code can understand yet but its progress. It may be the reversed labels issue.

Keep in mind, I am using the library example. This is 100% for sure my wiring or a flaky device, it is NOT software.

@will No, I assume lib modules are ok. Not a good use of my time.

@ronalex4203 

That list mentioned the module being set to reading some kind of "binary mode" instead of ASCII character sentences. Did you see anything about setting the mode in the documentation ?

@will No, haven't reaf anything, no need this is the sample code with the library. Thousands of others used it no problems. I have written 0 code, just connected it.

@ronalex4203 

What GPS module are you using ?

Do you think it's defective, i.e. does your setup work with any of the other 9 modules or do they all behave the same way ?

@will My back is bothering me at the moment so I am taking a break, then I will solder some pins on another module and try it. One of the tests do finally show a count of chars read. It increased for some time and I also saw some errors counted. Using Bill's code it just sits there waiting for data. What do you ground yourself to when handling these sensitive chips?

@ronalex4203

After CMOS chips, I don't worry all that much about grounding myself. If I now feel that I'm handling something that sensitive I'll go and take a firm grip on my metal kitchen faucet.

I used to use a grounding bracelet that plugged into a grounded electrical socket and used the ground part of the plug to connect to the wrist.

I don't like shocks, so I used to tripe-check that the power bar's ground was properly attached and that the wrist trap connected properly and so on as far back as I could 🙂

Now I use a silicone soldering mat for most work (solder or not). I like o think that helps too 🙂

Hope your back feels better.

@ronalex4203 

Another stupid question ... when you tested the module, did you turn it upside down so that the silver "button" thing was exposed to the sky ?

@will I am not sure, but it was in differing orientations over time. I did find one interesting thing, I can't find a baud spec on the device datasheet so I tried different speeds and did get some data although the year was 2020 the month 0 and the day 0. I am working tomorrow but on Sunday I will try Bill's sketch and vary the baud to see what happens. His sketch return proper sentences in that they start with the right chars and I did find an online decoder. The decoder didn't like anything I gave it however. My GPS is a different kind, it's a BLOX NEO-6M-0-001. I think it's a low end unit, so maybe I should try slower baud rates.

BTW, what is the silver button, the part that is 3mm or the part that is 24mm?

Before I went out, I noticed this chip is a 3V chip, but I was following Bills sketch and used 5V. It did not seem to kill the board but maybe made it misbehave?

Posted by: @ronalex4203

@will I am not sure, but it was in differing orientations over time. I did find one interesting thing, I can't find a baud spec on the device datasheet so I tried different speeds and did get some data although the year was 2020 the month 0 and the day 0. I am working tomorrow but on Sunday I will try Bill's sketch and vary the baud to see what happens. His sketch return proper sentences in that they start with the right chars and I did find an online decoder. The decoder didn't like anything I gave it however. My GPS is a different kind, it's a BLOX NEO-6M-0-001. I think it's a low end unit, so maybe I should try slower baud rates.

Worth a try.

BTW, what is the silver button, the part that is 3mm or the part that is 24mm?

It may not apply to that module, but on the BeiTian type the antenna (sort of looks like a silver button) is on the "bottom" side. That is, the opposite side of the soldered components, so if you held it with the works on top it would have blocked the antenna and could result in bad/no reception.

I looked up your module and it looks the same, so you'll need to test yours with the populated side facing down.

@will I don't know what you saw but mine has nothing on the back and it has an external antenna.

@ronalex4203 

That's interesting. I was looking at this article ...

https://create.arduino.cc/projecthub/ruchir1674/how-to-interface-gps-module-neo-6m-with-arduino-8f90ad

I'm really confused - the "silver button" is the silver dot showing inside the white surface on the top part in the picture on the right. It should be pointing up when in use.