M5 Fire and the IMU

moelski

Hi @all,
to be honest I´m a little bit confused about the M5 Fire device. As stated in the documentation there is a MPU6050+MAG3110 build in the fire.

So there are some questions (at least for me) unanswered :-)

Why is there a MPU6050+MAG3110 combination build in the fire where the gray one has a MPU-9250 ?
How can you use code from the M5 gray on the fire without recoding the whole IMU stuff?
Why tells the github example that there is a MPU9250 in the fire :
https://github.com/m5stack/M5Stack/blob/master/examples/Fire/M5StackFire_MPU9250/M5StackFire_MPU9250.ino

Very confusing at all. Is anyone here able to bring a little bit of light into the darkness :-) ?

Dominik

Rop

I'm afraid the M5Stack devices are notoriously poorly documented by the makers. I have tried to document the various M5Stack modules here, I have tried to figure out as much as possible about the FACES keyboard (unsuccesfully, mostly) but I haven't looked into the gyro/mems/magnetometer/etc side of things.

It really sucks that the people making these things never answer any questions...

High on the list, among other things:

Schematics for all devices, all versions. (e.g. M5Stack FIRE)
Schematics for FACES keyboard
Lists of hardware modifications between and within the different model series

ChrisMicro

@moelski 在 M5 Fire and the IMU 中说：

Why is there a MPU6050+MAG3110 combination build in the fire where the gray one has a MPU-9250 ?

Hmm, good question. I had also no information about the schematic when I made this example. I just tried to gather this information from the internet.

There is the original example for many M5Stack types and I just tried it and it worked.
https://github.com/m5stack/M5Stack/blob/master/examples/Modules/MPU9250/MPU9250BasicAHRS/MPU9250BasicAHRS.ino
But because I found it to bloated to work as an example I reduced it to the one you found.

There was no feedback from anyone yet if it works or not. On my M5Stack it works.

If you want, you can try many more examples in my repo:
https://github.com/ChrisMicro/M5Stack/tree/master/examples/Fire
and give me feedback.

The I2C scanner example shows two I2C devices at address 68 and 75.
There is no device at address 0x0e which would be the magnetometer. So I assume the magnetometer is build in the IMU and than it should be a MPU9250.
At least in my M5Stack Fire. But probably the changed the schematic.

moelski

Hi !

@rop 在 M5 Fire and the IMU 中说：

It really sucks that the people making these things never answer any questions...
You named it ... These are so exiting devices, but if you study the docs I have to facepalm my self sometimes :-)

@ChrisMicro
Thx for the link to your repo. Unfortunately I don´t have a fire yet. I ordered a black one (where I didn´t know that the IMU is not available). And then I ordered a gray one. It took 4 weeks to get the gray one to germany. I know it has arrived some days ago but I´m on vecation until saturday :-)
The black one is still missing - for 5 weeks now. I really hope it arrives, soon.

So I will do my first tests on saturday or sunday. And I´m still unsure if I should order a fire. Is it worth the price ... and did I really need the additional features?

I´m working on a data glove at the moment where I will use the gray M5Stack - or let´s say I hope I can use the M5 in general. I hope it´s not to heavy and I can mount it on top of the glove. But that´s a little bit OT now ...

Will see if I order a fire for some detailed testing :-)

Dominik