LPC82x I2C freeze/hang

krissielski — Wed, 11 Apr 2018 12:05:00 GMT

I am using the LPC824 with LPCOpen and if I attempt more than one I2C access in a row, the I2C hangs.

Using the LPC824 example project "periph_i2cm_polling" and modifying it to do 2 consecutive reads from a Si7021 (Humidity and temp), it consistently hangs in the LPCOpen driver code.

<< i2cm_8xx.c >>

/* Transmit and Receive data in master mode */
uint32_t Chip_I2CM_XferBlocking(LPC_I2C_T *pI2C, I2CM_XFER_T *xfer)
{
uint32_t ret = 0;
/* start transfer */
Chip_I2CM_Xfer(pI2C, xfer);

while (ret == 0) {
/* wait for status change interrupt */
while (!Chip_I2CM_IsMasterPending(pI2C)) {} <<<<<<< HANGS HERE ON THE SECOND READ
/* call state change handler */
ret = Chip_I2CM_XferHandler(pI2C, xfer);
}
return ret;
}

Even if I add a small delay (10ms or so) in between reads, it still freezes once in a while.

I have tried LPCOPEN 2.19 (default for MCUXpresso v10.1.1) and 3.02

Is there a cause/fix for this condition?

Re: LPC82x I2C freeze/hang

victorjimenez — Wed, 11 Apr 2018 18:00:24 GMT

Hi Kris,

Please refer the next community post:

I²C malfunction/freezing of lpc824 I²C communication

Hope it helps!

Victor.

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LPC82x I2C freeze/hang

Re: LPC82x I2C freeze/hang