<![CDATA[RFID Unit issues]]>Hi,

I'm using RFID Unid with RFID cards and I experience problems.
I can read UID, if card is on, read and write blocks however I need to go out and put the card back between each command otherwise it doesn't work.
For exemple, if I send 2 consecutive isCardOn(), only the first one returns True, the second one and more return False.

Is there anyone who has experienced the same problem?.

Thanks

]]>https://community.m5stack.com/topic/3318/rfid-unit-issuesRSS for NodeThu, 07 May 2026 23:38:45 GMTThu, 27 May 2021 03:49:30 GMT60<![CDATA[Reply to RFID Unit issues on Wed, 09 Jun 2021 02:17:11 GMT]]>Hi,

I found a solution.
I have to limit the I2C frequency to 100,000kbps otherwise it won't work properly.
This is strange because a frequency of 400,000 kbps works for all other devices and the MFRC522 should work fine at that frequency.

If anyone has any idea on this limitation, I am very interested.

Thank you

]]>https://community.m5stack.com/post/14047https://community.m5stack.com/post/14047Wed, 09 Jun 2021 02:17:11 GMT<![CDATA[Reply to RFID Unit issues on Tue, 01 Jun 2021 02:04:27 GMT]]>Hi,
Thank you for your reply.
Yes, I tried with 3 other cards and it's the same.
I have done more tests and it is very surprising.

The RFID card is located on the top of the device.
In an infinite loop, I just continuously check isCardOn () and measure the time between each detection.
Without moving the card of the device, I measure 11 detections continuously with 1.2 seconds between each detection and nearly 6 seconds between the 11th and 12th then another 11 measurements with 1.2 seconds .....

If I remove the card and put it on quickly, I can measure times less than 1 second.

]]>https://community.m5stack.com/post/13970https://community.m5stack.com/post/13970Tue, 01 Jun 2021 02:04:27 GMT<![CDATA[Reply to RFID Unit issues on Thu, 27 May 2021 11:40:48 GMT]]>that is so weird. did you have another card for the test? or all card has same situation?

]]>https://community.m5stack.com/post/13901https://community.m5stack.com/post/13901Thu, 27 May 2021 11:40:48 GMT