About LltWc

LltWc · 2024-12-18

I've been seeing some unexpected failure modes while reading T2Ts with an ST25R3916. Every ~300ms, the device sends a wake request, and if a tag is detected, goes ahead with the reading process. If a tag is detected and an error occurs anywhere in th...

LltWc · 2024-12-03

I'm trying to figure out some unexpected behavior (that I've posted about before) after successfully implementing alternation between T2T Card Emulation and Reader/Writer such that they seem simultaneous to the end user.During device initialization, ...

LltWc · 2024-10-01

I'm working on emulating a T2T with my device. It successfully makes it through automatic anticollision, then starts looking for commands. When I see 0x30 0x00, I go ahead and send the first 16 bytes, but the reader does not react or show the read da...

LltWc · 2024-09-25

I've been working on implementing tag emulation on my device with an ST25R3916 and have run into a problem. First - the code is currently completely separate from the tag reader code, including init, so it's not a matter of not changing modes properl...

LltWc · 2024-08-29

As we've been integrating the ST25R3916 into our final hardware, there's been an issue with the Adjust Regulators command. On external supply power, the command works without any problems. On some (not all) of our battery-powered units, as tested in ...

LltWc · 2024-12-24

This is custom firmware, the RFAL isn't compliant with the requirements for our RTOS-based system. Yes, wake is a WUPA command. Every time the device goes to Reader Mode, it sends a WUPA to try to detect a tag.While continuing to look for a fix, I sp...

LltWc · 2024-12-18

I have some traces attached that I got earlier this week, digital and analog, although I now realize that I must not have had the IRQ line attached securely enough because it's low for the entire timespan. This specific trace was to figure out why in...

LltWc · 2024-12-03

Follow up after checking again this morning: now the IRQ pin goes high after the interrupts are read. This shouldn't be possible so far as I'm aware.[00:00:16.156,463] <dbg> st25r3916: adjust_regulator: IRQ pin pre-enable: 0 [00:00:16.156,768] <dbg> ...

LltWc · 2024-10-08

Well, this is embarrassing, but that was it. I messed around with ATQA order when I was initially populating PT_MEM because I wasn't sure which went first, but I had left it alone since then.Now it works with all three test phones: Pixel 6a, Galaxy F...

LltWc · 2024-10-08

Understood, thanks. I improved some of the state transitions and resolved a hardware issue that was affecting the antenna range and now I can read pretty consistently with a Pixel 6a, but not with a Galaxy Fold or iPhone.Also, a few questions on the ...

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User Activity

Mitigating hard framing and CRC errors in Reader/Writer mode

Unexpected interrupt after Tx enable on ST25R3916

T2T Emulation Response Failure

Tag Emulation not going to ACTIVE

ST25R3916 Adjust Regulators not completing without a tag in the field

Re: Mitigating hard framing and CRC errors in Reader/Writer mode

Re: Unexpected interrupt after Tx enable on ST25R3916

Re: Unexpected interrupt after Tx enable on ST25R3916

Re: T2T Emulation Response Failure

Re: T2T Emulation Response Failure