Question How to build a truly Custom FW?

[BodaAllMighty]

Hello everyone,

First of all congrats on a great job, the custom resources and translation look amazing.
And those got me thinking if we could detect something like a double tap for example this could lead to some very interesting things.

I'm developer and as such when the idea occurred to me I started sniffing the BT traffic to see what I could get out of band.
Unfortunately it seems that by default this sort of event is only generated when the user selects the Heart Monitor option.

So my question is simple can we build or own homebrew fw for Mi band ?
Do we have access to the right tools?

I would start by trying to detect the double tap and trigger an event. After this maybe build a custom menu with different action / events.

Is this viable, is there any one else trying to get this to work this way or something similar?

 

[gungoryahya]

up+

 

[baburbbr]

Resource file can be uncompile but .fw is not. I wonder too how modify firmware file. May some one share list offset adresses for modify with hex editor.

 

[MagicalUnicorn]

Use an Hex Editor to edit firmware.

At your own risk .

 

[victorjvs]

Use an Hex Editor to edit firmware.

At your own risk .

Hexadecimal editor?!

 

[MagicalUnicorn]

Hexadecimal editor?!

Yes .

 

[tparaizo]

I even changed a fw using a hex editor, but it was a simple change. I changed the id from version 1.5.0.2 to 1.6.0.16, to circumvent the Mi Fit update and prevent it from returning to Chinese, and it worked perfectly, I even posted it on another forum thread.
However, when I took a little more risk to translate a version 1.6.0.16_PT-TP into PT-BR, I ended up damaging my Mi Band. She gave a brick, does not turn on, does not light, does not give any sign of life I'm even after some way to give a new flash of fw via USB, or some other interface that is available on her board. and try to see the options.
On this my second attempt (failure) I used a different hex editor, another O.S. and did it in a hurry, so I can not rule out any possibility of failure, neither the editor nor mine. Maybe if there was a way to validate fw before uploading to Mi Band, or making an emulation, or even a physical way to do this update, with some eprom recorder, it would be a lot simpler for these cusotmizations.
This is my experience for those who want to venture. Very careful.
Hugs

 

[MagicalUnicorn]

I even changed a fw using a hex editor, but it was a simple change. I changed the id from version 1.5.0.2 to 1.6.0.16, to circumvent the Mi Fit update and prevent it from returning to Chinese, and it worked perfectly, I even posted it on another forum thread.
However, when I took a little more risk to translate a version 1.6.0.16_PT-TP into PT-BR, I ended up damaging my Mi Band. She gave a brick, does not turn on, does not light, does not give any sign of life I'm even after some way to give a new flash of fw via USB, or some other interface that is available on her board. and try to see the options.
On this my second attempt (failure) I used a different hex editor, another O.S. and did it in a hurry, so I can not rule out any possibility of failure, neither the editor nor mine. Maybe if there was a way to validate fw before uploading to Mi Band, or making an emulation, or even a physical way to do this update, with some eprom recorder, it would be a lot simpler for these cusotmizations.
This is my experience for those who want to venture. Very careful.
Hugs

Update a older firmware version for use it with the latest Mi Fit isn't good idea. If the latest Mi Fit contain a new firmware and new features, use an older firmware with this newer Mi Fit is useless... You will don't have the new features, and maybe you will have bugs. So, you gain nothing...

It's easy to brick the Mi Band 3 with a wrong firmware modification, it's why we don't make Tutorial like Resources modification.

If you don't want lost your Mi Band 3, be patient and wait we release firmwares .

 

[tparaizo]

Update a older firmware version for use it with the latest Mi Fit isn't good idea. If the latest Mi Fit contain a new firmware and new features, use an older firmware with this newer Mi Fit is useless... You will don't have the new features, and maybe you will have bugs. So, you gain nothing...

It's easy to brick the Mi Band 3 with a wrong firmware modification, it's why we don't make Tutorial like Resources modification.

If you don't want lost your Mi Band 3, be patient and wait we release firmwares .

I totally agree.
The issue of changing the version, would be only a temporary alternative, but knowing of all the disadvantages and risks.

Can you tell if there is an interface available to record the firmware, other than via bluetooth?

Hugs!

 

[MagicalUnicorn]

I totally agree.
The issue of changing the version, would be only a temporary alternative, but knowing of all the disadvantages and risks.

Can you tell if there is an interface available to record the firmware, other than via bluetooth?

Hugs!

I don't know if it's possible (or how) unbrick the Mi Band 3.

 

[tparaizo]

I don't know if it's possible (or how) unbrick the Mi Band 3.

Okay, thank you. I will soon open that damaged and analyze.
Hugs.