<![CDATA[[Solved] UnitV unable to find april-tags]]>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?

]]>https://community.m5stack.com/topic/2150/solved-unitv-unable-to-find-april-tagsRSS for NodeWed, 29 Apr 2026 06:48:25 GMTWed, 22 Jul 2020 19:17:15 GMT60<![CDATA[Reply to [Solved] UnitV unable to find april-tags on Thu, 09 Feb 2023 12:04:00 GMT]]>@hague good to see! Could you tell me how fast it can run? FPS and at resolution? Thanks!

]]>https://community.m5stack.com/post/20055https://community.m5stack.com/post/20055Thu, 09 Feb 2023 12:04:00 GMT<![CDATA[Reply to [Solved] UnitV unable to find april-tags on Thu, 23 Jul 2020 22:34:53 GMT]]>@hague thanks for the info that's a newer version than I have cheers

]]>https://community.m5stack.com/post/9426https://community.m5stack.com/post/9426Thu, 23 Jul 2020 22:34:53 GMT<![CDATA[Reply to [Solved] UnitV unable to find april-tags on Thu, 23 Jul 2020 19:56:03 GMT]]>@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

]]>https://community.m5stack.com/post/9425https://community.m5stack.com/post/9425Thu, 23 Jul 2020 19:56:03 GMT<![CDATA[Reply to [Solved] UnitV unable to find april-tags on Wed, 22 Jul 2020 22:19:57 GMT]]>Nice one, what firmware are you using for the UnitV?

]]>https://community.m5stack.com/post/9415https://community.m5stack.com/post/9415Wed, 22 Jul 2020 22:19:57 GMT<![CDATA[Reply to [Solved] UnitV unable to find april-tags on Wed, 22 Jul 2020 21:06:03 GMT]]>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:

UnitV QRcode failure

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

sensor.set_vflip(1)

After that, the QR code was detected correctly:

UnitV QRcode correctly

Now, also april tags are working:

UnitV april tag correctly

]]>https://community.m5stack.com/post/9413https://community.m5stack.com/post/9413Wed, 22 Jul 2020 21:06:03 GMT<![CDATA[Reply to [Solved] UnitV unable to find april-tags on Wed, 22 Jul 2020 20:48:27 GMT]]>In addition to the code, here are some screenshots:

M5StickV with the above code:
M5StickV
As you can see, the april tags are detected correctly (output in the serial terminal)

UnitV with the same code:
UnitV
No tags are detected...

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

]]>https://community.m5stack.com/post/9412https://community.m5stack.com/post/9412Wed, 22 Jul 2020 20:48:27 GMT