RF430CL330H interrupt clear problem

[ejleiss]

Hello,

Has anyone ever used the RF430CL330H NFC/RFID breakout board? I am having a problem clearing the interrupt flag. I set my registers to the following values:

INT_ENABLE = 0xFF, 0xFA, 0x06, 0x00 --> End of Read/End of Write Enabled
CONTROL_REG = 0xFF, 0xFE, 0x16, 0x00 --> INTO DRIVE = actively driven high/low, INTO HIGH = active high, ENABLE INT = output enabled, ENABLE RF = interface enabled
INT_FLAG = 0xFF, 0xF8, 0x06, 0x00 --> End of Read/End of Write = 1 --> Clear int flags

When it senses and RF presence via smartphone, the INTO pin goes high and starts my interrupt routine. I then send the following register commands

CONTROL_REG = 0xFF, 0XFE, 0x14, 0x00 --> Disable RF, leave all other settings alone
INT_FLAG = 0xFF, 0xF8, 0x06, 0x00 --> Clear End of Read/End of Write int flags
INT_ENABLE = 0xFF, 0xFA, 0x00, 0x00 --> Disable End of Read/End of Write

If NDEF message needs to be modified, do this here.

INT_ENABLE = 0xFF, 0xFA, 0x06, 0x00 --> End of Read/End of Write Enabled
CONTROL_REG = 0xFF, 0xFE, 0x16, 0x00 --> INTO DRIVE = actively driven high/low, INTO HIGH = active high, ENABLE INT = output enabled, ENABLE RF = interface enabled

Now, I expect the INTO pin to be low again and waiting to be interrupted again. However, the INTO pin never seems to clear, it stays high.
Am I doing something wrong with my routine? My interrupt pin on my micro seems to work fine if I trip it externally (not via the INTO pin from the NFC tag). It clears without an issue. Only when it is connected to the INTO pin of the tag does it stay high.

Thanks for any help.

 

[spirilis]

Hi there- Registered just to post a reply here.

This vexed me as well, as it turns out you need to do:
INT_ENABLE = 0x00
INT_FLAG = <whatever IRQs need to be cleared>
INT_ENABLE = 0xFF
in order to properly clear the INTO pin state. TI's own example code does this although it doesn't provide any explicit detail on why or how mandatory this is, but in my experience it's the only way you can get the INTO line to clear.

 

[biff44]

the digital parts of these RF chips are always flakier than dandruff.
I always TRY to buy the chip on a demo board with some sort of laptop interface software, so we can reverse engineer exactly what digital signals are being sent to the chip, what order, what clock timing, etc etc. I shipped one job where we programmed all the registers TWICE for every frequency change--it needed that to make it take the data. lol