@kylebuttress Same as for the M5StickV
M5StickV_Firmware_v5.1.2.kfpkg
and
maixpy_v0.5.0_98_gbd7c7ab_m5stickv.bin

downloaded here:
https://dl.sipeed.com/MAIX/MaixPy/release/master

Hi, Maybe flipping the sensor image will fix this:

sensor.set_vflip(1)

This was the solution for my problem with april tags and QR-Codes.

OK, I found the cause: The image from the camera was mirrored. So the tag could not be detected. I found the error when I tried to detect QR codes:

Then I added the following line of code to mirror the image:

sensor.set_vflip(1)

After that, the QR code was detected correctly:

Now, also april tags are working:

In addition to the code, here are some screenshots:

M5StickV with the above code:

As you can see, the april tags are detected correctly (output in the serial terminal)

UnitV with the same code:

No tags are detected...

Same firmware, same MaixPy version, same code... But a different behavior...

I can detect april-tags with the StickV, but not with the UnitV AI camera. For the UnitV I use the same code, but without the LCD calls. Here's the code:

import sensor
import image  
import math

print("start script")

sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QQVGA) # 160 x 120 pixel
sensor.run(1) 
sensor.skip_frames(30)

print("start loop...")

while True: 
    img=sensor.snapshot()
    tags = img.find_apriltags() # defaults to TAG36H11 without “families”.   
    if len(tags) > 0:
        for tag in img.find_apriltags(): # defaults to TAG36H11 without “families”. 
            #img.draw_rectangle(tag.rect(), color = (255, 0, 0))
            #img.draw_cross(tag.cx(), tag.cy(), color = (0, 255, 0))
            degress = 180 * tag.rotation() / math.pi
            print(tag.id(),degress)

I have uploaded the latest firmware. What can be the reason that no april-tags are detected?

@puijkh Same for me with april tags. Did you found a solution?

Hello,
On one of my M5Stack devices the battery in the bottom module is swollen. That worries me!
I have used the M5Stack with the additional battery module. Then both batteries are connected in parallel, right?
Can that be the cause? Has anyone ever observed this when using the extra battery module?

@m5stack Many thanks for the quick help. With the spare part the BALA now works perfectly!

It also took me a little while to get the BALA up and running. Then I made a little video as a kind of manual. Maybe it helps the one or the other.
https://youtu.be/iYmJmg_pJ74
If it does not behave this way at all, for example if the green LEDs on the motors do not light up at all, then it is possible that the motor driver is damaged.

I have achieved quite good results with the Seeed Studio Grove 3-Axis Digital Compass V2.
https://wiki.seeedstudio.com/Grove-3-Axis_Digitial_Compass_v2.0/