LPC Microcontrollers中的主题 I2C Master Acking after Receive https://community.nxp.com/t5/LPC-Microcontrollers/I2C-Master-Acking-after-Receive/m-p/565218#M17036 <HTML><HEAD></HEAD><BODY><STRONG>Content originally posted in LPCWare by elsingc on Mon Jun 22 05:38:23 MST 2015</STRONG><BR /><SPAN>I am using the LPC810 with the HMC5883L. I have it all working except the receive part. Whenever I go to receive something, it will read in the data, however, there is always a NACK when I want to stop transmission. I believe this is causing the HMC5883L to then want to resend the old data as I cannot get the updated data. My code flow is below.</SPAN><BR /><BR /><SPAN>Load MSTDAT with ((Address &lt;&lt; 1) | 1)</SPAN><BR /><SPAN>Set CTRL to start</SPAN><BR /><SPAN>uint32_t temp = MSTDAT</SPAN><BR /><SPAN>set CTRL to stop.</SPAN><BR /><BR /><SPAN>Its very simple. One thing I noticed is that if I read twice, the first byte read is acked, but the last byte is always nacked. I think I am not stopping it correctly. Does anybody know whats up?</SPAN></BODY></HTML> Wed, 15 Jun 2016 20:06:32 GMT lpcware 2016-06-15T20:06:32Z I2C Master Acking after Receive https://community.nxp.com/t5/LPC-Microcontrollers/I2C-Master-Acking-after-Receive/m-p/565218#M17036 <HTML><HEAD></HEAD><BODY><STRONG>Content originally posted in LPCWare by elsingc on Mon Jun 22 05:38:23 MST 2015</STRONG><BR /><SPAN>I am using the LPC810 with the HMC5883L. I have it all working except the receive part. Whenever I go to receive something, it will read in the data, however, there is always a NACK when I want to stop transmission. I believe this is causing the HMC5883L to then want to resend the old data as I cannot get the updated data. My code flow is below.</SPAN><BR /><BR /><SPAN>Load MSTDAT with ((Address &lt;&lt; 1) | 1)</SPAN><BR /><SPAN>Set CTRL to start</SPAN><BR /><SPAN>uint32_t temp = MSTDAT</SPAN><BR /><SPAN>set CTRL to stop.</SPAN><BR /><BR /><SPAN>Its very simple. One thing I noticed is that if I read twice, the first byte read is acked, but the last byte is always nacked. I think I am not stopping it correctly. Does anybody know whats up?</SPAN></BODY></HTML> Wed, 15 Jun 2016 20:06:32 GMT https://community.nxp.com/t5/LPC-Microcontrollers/I2C-Master-Acking-after-Receive/m-p/565218#M17036 lpcware 2016-06-15T20:06:32Z