Logging heading and inclination for Geotagging

[bwims]

Hello, I’ve had this idea to be able to incorporate direction and maybe angle of elevation into geotagging metadata using the Pi Zero and the BerryIMU.

Currently I use my phone to log GPS coordinates while taking photos which I merge into the metadata later. However, I would like to know which direction I’m pointing (and inclination if possible)

The idea would be to connect a hotshoe foot to a 3d printed case such that when a photo is taken the Zero would log the current direction and inclination of the IMU. There would need to be a calibration button once it is fitted and pointing North at the horizon. I would also expect the clock to have been synced with the internet recently.

Can anyone point me at the specific routines already provided on Git, or will I have to read through it all and understand it first? 🙂

NB these devices cost hundreds for Canon cameras, and they only work with the high-end models.

[Mark Williams]

What you want is possible with the BerryIMU, in theory.

Regarding heading, you would need to include tilt compensation, which our code has.
If you are out and about when you take your photos, then you would only need to calibrate it once for hard iron distortion, this page as some info on this. https://ozzmaker.com/compass3/.

When you say ‘declination’, are you talking about the deviation from the true vertical or horizontal? If “yes”, the gyro and accelerometer can give you these values.
I assume you will have a button to press to capture this data whenever a photo is taken?

Mark --OzzMaker.com --

[bwims]

Hi Mark, thanks for replying!

I envisage a button press to calibrate the time if there is an internet connection and one to calibrate when facing North as per a magnetic compass. Not sure about accounting for magnetic declination.

I’m of the understanding that two of the hot shoe connections can be used as a simple button press, but I have not checked this. It would be nice to mount the Zero on the hot shoe to allow for grabbing the direction.

Apparently, geotagging for heading, tilt and range have been proposed by Flickr and described here:
wiki tags

I have no idea how to incorporate range, but general direction would suit me to start with!

As you have probably got most of your code “in your head”, do you think it would be possible to parcel up the system into a callable routine?

Other ideas that I have might be to talk to my phone using bluetooth or wifi using this nifty add-on.
IO hat and perhaps use it as a backup (or primary) datalogger.

B.

[Mark Williams]

If you can use the hot shoe as a button press.. then it is easy to modify our existing code to capture the data. You would just need to add a timestamp to the output.

When you first start, it would also be ideal to also log the raw sensor values as well, because if you make a mistake with the calculations… you can always recalculate if you have the raw sensor values.

Regarding declination.. I haven’t really looked into this, but if you are capturing the GPS coordinates, maybe there is an online resource where you can grab the declination values based on your GPS coords, and apply this to your heading.

I am happy to assist. And if you do get it working, I would love to post about it on our site.

Do you know Python or C?

BTW: We are developing a GPS module where you can use I2C or UART to capture the coords. It will also have a mounting hole where a BerryIMU can be placed.

Mark --OzzMaker.com --

[bwims]

Hello again Marx,

I know Python, haven’t touched C for so long I wouldn’t care to now – life’s too short! 🙂

I’m very interested in the GPS module! (depending on cost, as ever).

Regarding detecting shutter press, it looks like Canon is too clever by half. It seems to check whether a valid flashgun in fitted before it enables the contacts. However, there may be scope for me to use Gphoto2 or something similar which detects an event.

Actually, I’m not that bothered about declination. Just to be able to know the general heading would be huge bonus when using map software to display where the picture was taken.

Many thanks for your help! I’d be happy for you to post about it if I manage to make it work!

B.

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