MAGRA gradiometer

[SimonS]

Hi guys
After long time I do make new easy to build DIY project call MAG-BOARD.
You can buy kit from my site www.fgsensors.com. I think think this is cheaper way to build high quality magnetometer/gradiometer.
I offer also open-source code, so everyone can make it as wish. MAG-BOARD use strong dual core processor with build BT and WiFi (ESP32) and SD card for recording. Also is available free arduino app for connecting with your phone.
I also make waterproof version of gradiometer with long cable.
Any comment are welcome. Geotech users have also special discount of 5% with code "geotech"

[bernte_one]

Hi Simon, is it also possible to save the logged datas onto the SD Card und export them into a pc software?

[SimonS]

Currectly FW (1.0) it is not possible. But like I say it is open-source program, so everyone can add it. In future I have also plan to add this. Also I'm working on 3D view on android app. If someone wont to help on this project it is wellcome. Also feedback is wellcome

[SimonS]

doable picture. Cannot delete

[Djallale]

I bought this set, but I want to know where to put the sound button, and can I connect it to a 3D application? Where do I put the Bluetooth parts, if possible?

[SimonS]

Hi
This is not magra. This is old mag-shield board. This has no connectivity to phone!

[Djallale]

Is it possible to install the role of the buttons? It is not clear how to operate it

[SimonS]

It is open source and open HW project. So you can add up to 3. buttons. You can simply add in code. It is published on www.fgsensors.com site. But keep in mind that there is no speaker.

[Djallale]

What can I use these 3 buttons for, and is there an audio port?

[Djallale]

[SimonS]

No, there is no audio output. Button can be used for whatever you wont. For nulling example. But you need to program it!
Keep in mind that mag-shield is only development board. Of course you can use it as gradiometer with included SW

[NIKKOLAY1]

Hello !!! I also have this device, but it is useless without the function of keeping it. I get to connect the memory card to it for recording data. Maybe someone will explain what kind of data should be recorded so that they can be visualized? Thanks.

[SimonS]

Mag-shield is old - development board for gradiometer.
Much better is mag-board who has phone connection, onboard buzzer and SD-card holder. SD card is not supported by currectly FW, but data can be recorded by phone app and import it Surfer or some other program.

[mrainbolt]

Simon,

I have order and received the Kit. You did an outstanding job!

I am in the process of assembling. I am taking the LCD input (scl and sda) and interfacing to a data logger from Sparkfun. I am also connecting my Trimble GPS to the data logger hoping to generate a cvs file for processing with software.

I am concerned about field interference from the GPS antenna dome that I hope to mount above the top fluxgate sensor and possible interference from any equipment I am carrying. I understand the signal field from the sensors is a figure 8 with the right angle horizontal being the weakest spot.
Any insight would be appreciated.

Carl in his article about building a gradiometer with the SCL007 suggested pointing the fluxgate sensors with the pins pointing down. Do you know why?
He also suggested a cap across the power line of the sensor, I assume that is now incorporated into the sensor?

One artifact I am trying to "see" is a 3 cm iron ball (canister shot). What is the minimum distance above ground surface should I be? I am constructing a 10 cm wide PVC fork for a 12 cm x 3 cm plastic wheel. This will keep me a constant distance from the ground and let me roll instead of carrying the pole.

The plus and minus sens pins, are they to limit the upper range of the uT scale?

Again thanks for the great kit.

Fred

[SimonS]

Hi Fred

Thanks!
GPS antenna shod not make to much disturb on gradiometer. I didn't try this, but I work with phone's GPS for record data and I didn't note any problems with that. Only keep it away from sensor as much you can 10cm minimum and during scan this object should not be moved.
No, our sensors are design, that it have better sensitivity at the top. So use it as is in manual. Perhaps FGM-3 has some different reception characteristic...
Also RC filter is integrated inside sensor, so there is no exkstra need for external cap here. But you can add it if you wont.
I think it is not so important different from ground. Well, I didn't test too much to be honest. Please correct me if I'm wrong!

+ and - is some kind of sensitivity, but units are not truly uT scale

Simon