HTRC110 communication
I'm trying to read HITAG card serial number (UID), I'm using HTRC11001t. Problem is that I don't know which command to send from uC. I've read datasheet for HTRC110 and application note, but I still don't understand how communication works (I am totally unexperienced with the subject and this is my first work assignment on my job). If I send 111----- for entering READ TAG mode, what should I do next in order to get card's serial number? I'm not interested in using crypto mode or any advanced options, just need to simply read serial number. If someone would tell me, or at least refer me to some other link or document that explains protocol with htrc, I would be very greatful.
Reference:AN98080 Read/write devices based on the HITAG read/write IC HTRC110, Section: 9.7 Reading out the digital data, Page: 46
Implementing a quasi-SPI interface which could receive the transponder data with the SCLK line held low during transmission would most likely be the direct method.
A schematic of the current design would be helpful in advise you further.
BigDog
Ok, thank you, but I still don't understand which command (or commands) should I send from uC in order to get card's UID.
You are sending the correct command, READ_TAG, however once the command is received the device enters transparent mode which automatically reads compatible transponders and remains in that mode as long as SCLK remains low.
When in transparent mode the device automatically reads any compatible transponders and outputs the RFID data on DOUT as outlined in the datasheet.
Note, SCLK must remain low or another READ_TAG command must be issued to return the device back to transparent mode.
BigDog
Ok, but if I enter READ TAG and if I'm getting some data from DOUT (some array of 1s and 0s), how do I know what it represents? As I wrote, I wan't to read HITAG card's serial number. If I have some data on DOUT, how can I be sure that it is serial number and not some other data?