CR95HF startup sequence and calibration

[Mickaël Bucher]

Posted on September 26, 2017 at 09:23

I use a CR95HF with UART communication. I make the startup sequence with t0= 200 us. I have 30 boards with CR95HF. One of them don't communicate with my microcontrolleur. I change t0 = 250 ms and after this operation, the communication begin. Why ?

Can I find a startup sequence with the typical values and maximal values ?

I have a second problem.

I want use the calibration process to increase the lenght of reception but this command don't send response.

With the other commands, I receive a response.

Why ?How much the calibration increase the lenght ? (millimeters or centimeters)

[Peter Boringer · Accepted solution]

Posted on October 11, 2017 at 15:43

Hello Mickael,

To answer your calibration needs the functionality is available on the CR95HF to tune the sensitivity of the reader in front of the Tag answer and not the reverse. Thus you will not increase transmission lenght by executing calibration, but you will improve tag detection.

For your startup issue can you please provide the version of the CR95HF by reading the IDN of the good and failing IC.

Then  explain how you measure the t0 timing? For my knowledge there is a min value of 100us to wake up,  max value doesn't make sense.

Regards