<![CDATA[Cat-M or CatM+GNSS Unit not working in UIFLOW - screen stays blank - [solved]]]>Hi all,
i ordered a bunch of units to try out some things.

When i connect the Cat-M or the CatM+GNSS to my Core2 oder StickCPlus it does not work with UIFLOW

For testing, i added a Label to the screen. When i push it to the device, the label shows.
Then i add the Unit. E.g. the Cat-M Modul to the device, in UIFLOW and connect the cable.
When i push the code to the device ( no additional Blocks added yet, just defined the Unit ), the screen stays blank, and the label is not displayed.

This behaviour is the same for the Cat-M unit, or the CatM+GNSS Unit.

Any ideas what might be wrong? I have connected the Core2 via usb to a additional power source, just to be sure.

I am talking about this two units:
https://shop.m5stack.com/collections/m5-sensor/products/sim7080g-cat-m-nb-iot-unit
or
https://shop.m5stack.com/collections/m5-sensor/products/sim7080g-cat-m-nb-iot-gnss-unit-with-telec-antenna

]]>https://community.m5stack.com/topic/4626/cat-m-or-catm-gnss-unit-not-working-in-uiflow-screen-stays-blank-solvedRSS for NodeSun, 12 Apr 2026 19:43:52 GMTWed, 21 Sep 2022 13:05:07 GMT60<![CDATA[Reply to Cat-M or CatM+GNSS Unit not working in UIFLOW - screen stays blank - [solved] on Thu, 22 Sep 2022 12:45:28 GMT]]>Hello @a1development

I am glad to hear you got it working and thank you for reporting back.

Thanks
Felix

]]>https://community.m5stack.com/post/18679https://community.m5stack.com/post/18679Thu, 22 Sep 2022 12:45:28 GMT<![CDATA[Reply to Cat-M or CatM+GNSS Unit not working in UIFLOW - screen stays blank - [solved] on Thu, 22 Sep 2022 12:06:41 GMT]]>Thank you all for your help.

I removed the pin from my sim card and now it works :)

]]>https://community.m5stack.com/post/18677https://community.m5stack.com/post/18677Thu, 22 Sep 2022 12:06:41 GMT<![CDATA[Reply to Cat-M or CatM+GNSS Unit not working in UIFLOW - screen stays blank - [solved] on Thu, 22 Sep 2022 02:03:46 GMT]]>Most of the time, if i wait about 5 minutes it works. It seems to be an initialization issue.

]]>https://community.m5stack.com/post/18672https://community.m5stack.com/post/18672Thu, 22 Sep 2022 02:03:46 GMT<![CDATA[Reply to Cat-M or CatM+GNSS Unit not working in UIFLOW - screen stays blank - [solved] on Wed, 21 Sep 2022 16:17:02 GMT]]>Hello @a1development

I think I know what might be going on. As part of the initialization the UIFlow code sends the AT command to check for a SIM PIN, e.g. AT+CPIN? and if it doesn't receive a +CPIN: READY it won't continue.

Make sure you have a IoT SIM card in your Cat-M unit which has the SIM PIN disabled.

Thanks
Felix

]]>https://community.m5stack.com/post/18667https://community.m5stack.com/post/18667Wed, 21 Sep 2022 16:17:02 GMT