GPS/GNSS Chip on PCB with ESP32 Chip

Hey Guys,

I am trying to do a project where both an ESP32 and GNSS chip are on the same PCB. The GNSS chip I am looking at is: Teseo-LIV3F datasheet . The ESP32 chip is the standard ESP-WROOM-32D. Sometimes these module datasheets will have example circuits that you can use to connect to your existing microcontroller, like through I2C comms. But I don't see an example on this GNSS chip's datasheet.

There are a few things that I don't understand that I think will be important to getting this circuit functional.
How would one attach an external antenna or just IPEX connection for one? Is this even necessary?
If I am going to use I2C comms can I just connect the GND, SDA, and SCL pins to microcontroller?

Is there any extra circuitry I should add around the chip to ensure that it is protected? Just seems like I am missing something.

I imagine it will look something like the circuit below:

Pinout looks like a Ublox MAX8Q and they dont need much in the way of support circuitry.

You need to build up a breadboard plug in module to test out the circuit you are planning, its not difficult.

How would one attach an external antenna or just IPEX connection for one? Is this even necessary?

Why would an antenna for a GPS not be necessary ?

srnet:
Pinout looks like a Ublox MAX8Q and they dont need much in the way of support circuitry.

You need to build up a breadboard plug in module to test out the circuit you are planning, its not difficult.

Why would an antenna for a GPS not be necessary ?

Alright so antenna is essential.
But what is going on in this portion of the circuit? Is it necessary for what I am doing?

circuit2.JPG

circuit2.JPG

The circuit you posted is for a Neo-6, but you did say you were using are you using a Teseo-LIV3F, so the circuit of a Neo-6 is of no relavence. Read through the datasheet of the Teseo-LIV3F does it say anything about a 24AA32A or other EEPROM ?

Some GPS can use an EEPROM for saving thier configuration.

If you are unsure of the circuit for your chosen GPS, you really should use a different GPS for which you can get a known good circuit.

srnet:
The circuit you posted is for a Neo-6, but you did say you were using are you using a Teseo-LIV3F, so the circuit of a Neo-6 is of no relavence. Read through the datasheet of the Teseo-LIV3F does it say anything about a 24AA32A or other EEPROM ?

Some GPS can use an EEPROM for saving thier configuration.

If you are unsure of the circuit for your chosen GPS, you really should use a different GPS for which you can get a known good circuit.

As I mentioned in post one, there was not an example circuit on this Teseo datasheet to work with. This is why I chose to post a circuit diagram from a similar GNSS module (IOs, ..etc) because I believe the solution I am looking for will look similar to this, and hence it is certainly relevant.
I appreciate your help but I am looking for a circuit specifically for this Teseo module, finding another module is outside the scope.

Hi.

Did you actually read the datasheet, or just do a visual scan for example or reference schematics ?

The datasheet mentions the Teseo suite (click !) which should help you configure the GNSS solution.
I'd get that software and play with it to see what you can learn from it (you might not learn anything if the suite requires an actual piece of hardware connected to your system).
Hmm, the suite's 2017 datasheet tells you the software was created for windows XP and Windows 7...
This datasheet also tells you the software is able to read, erase and write the internal configuration EEPROM, so that is a direct answer to one of your questions.

Maybe you should start with this tool before you spend any money.

MAS3:
Hi.

Did you actually read the datasheet, or just do a visual scan for example or reference schematics ?

The datasheet mentions the Teseo suite (click !) which should help you configure the GNSS solution.
I'd get that software and play with it to see what you can learn from it (you might not learn anything if the suite requires an actual piece of hardware connected to your system).
Hmm, the suite's 2017 datasheet tells you the software was created for windows XP and Windows 7...
This datasheet also tells you the software is able to read, erase and write the internal configuration EEPROM, so that is a direct answer to one of your questions.

Maybe you should start with this tool before you spend any money.

Thanks for the comments. And to answer your question, I did not do an in-depth read of the datasheet. I see the remark about EEPROM, I am not familiar with this so I will have to do some reading but it sounds as if this portion of the circuit is necessary.

Hmm I was not expecting to have to go through a software for communications...

I can't do windows, but would it help if I wired this module to a Linux machine like Rpi through UART comms? I see that is what most GNSS module tutorials are doing. Does ESP just lack the configuration necessary to easily communicate with this module?

In the past I have used this code to find latitude and longitude on Rpi for a similar GNSS module.

   try:
            port1 ='/dev/serial/by-id/usb-u-blox_AG_-_www.u-blox.com_u-blox_7_-_GPS_GNSS_Receiver-if00'  
            serialPort1 = serial.Serial(port1,baudrate = 115200, timeout = 0.5)
            str =serialPort1.readline().decode()
            if str.find('GGA') > 0:
                msg = pynmea2.parse(str)
                latitude = round(msg.latitude,8)
                longitude = round(msg.longitude,8)
            else:
                latitude = latitude
                longitude = longitude
        except:
            error = 2
            print('GPS comms failure')

feynman137:
I see the remark about EEPROM, I am not familiar with this so I will have to do some reading but it sounds as if this portion of the circuit is necessary.

Please explain what "internal EEPROM" means to you and what part of which circuit you meant by that answer.


The ESP-WROOM-32D module supports all 3 UART ports available from the chip.
All you need to do is find some way to have GPS and ESP hardware communicating on voltage levels compatible to each other (if they aren't already compatible).

(click image for a larger version from the source i used)

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