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    <title>topic I2C code problem with Srf08 ultrasonic sensors with LPC1758 in LPC Microcontrollers</title>
    <link>https://community.nxp.com/t5/LPC-Microcontrollers/I2C-code-problem-with-Srf08-ultrasonic-sensors-with-LPC1758/m-p/517822#M2363</link>
    <description>&lt;HTML&gt;&lt;HEAD&gt;&lt;/HEAD&gt;&lt;BODY&gt;&lt;STRONG&gt;Content originally posted in LPCWare by hoiyin00 on Thu Apr 24 13:06:09 MST 2014&lt;/STRONG&gt;&lt;BR /&gt;&lt;SPAN&gt;Hi all,&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;I have studied how to set up for I2C for Srf08 sensor. however, I dont know how to write it to the LPC1758 I2C controller.&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;From the I2C Example I used in MCB1700 example code bundle. I dont understand how to the step below in the i2cmst.c &lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;Can anyone share their experience on that to help solve the problem please?&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt; &lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;Here is the steps for the I2C to write and read to sensor&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;write to sensor&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;i2c_start();&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // send start sequence&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;i2c_tx(0xE0);&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // SRF08 I2C address with R/W bit clear&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;i2c_tx(0x00);&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // SRF08 command register address&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;i2c_tx(0x51);&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // command to start ranging in cm&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;i2c_stop();&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // send stop sequence&lt;/SPAN&gt;&lt;BR /&gt;&lt;BR /&gt;&lt;SPAN&gt;read from sensor&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;i2c_start();&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // send start sequence&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;i2c_tx(0xE0);&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // SRF08 I2C address with R/W bit clear&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;i2c_tx(0x01);&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // SRF08 light sensor register address&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;i2c_start();&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // send a restart sequence&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;i2c_tx(0xE1);&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // SRF08 I2C address with R/W bit set&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;lightsensor = i2c_rx(1);&amp;nbsp; // get light sensor and send acknowledge. Internal register address will increment automatically.&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;rangehigh = i2c_rx(1);&amp;nbsp;&amp;nbsp;&amp;nbsp; // get the high byte of the range and send acknowledge.&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;rangelow = i2c_rx(0);&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // get low byte of the range - note we don't acknowledge the last byte.&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;i2c_stop();&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // send stop sequence&lt;/SPAN&gt;&lt;BR /&gt;&lt;BR /&gt;&lt;/BODY&gt;&lt;/HTML&gt;</description>
    <pubDate>Wed, 15 Jun 2016 17:29:46 GMT</pubDate>
    <dc:creator>lpcware</dc:creator>
    <dc:date>2016-06-15T17:29:46Z</dc:date>
    <item>
      <title>I2C code problem with Srf08 ultrasonic sensors with LPC1758</title>
      <link>https://community.nxp.com/t5/LPC-Microcontrollers/I2C-code-problem-with-Srf08-ultrasonic-sensors-with-LPC1758/m-p/517822#M2363</link>
      <description>&lt;HTML&gt;&lt;HEAD&gt;&lt;/HEAD&gt;&lt;BODY&gt;&lt;STRONG&gt;Content originally posted in LPCWare by hoiyin00 on Thu Apr 24 13:06:09 MST 2014&lt;/STRONG&gt;&lt;BR /&gt;&lt;SPAN&gt;Hi all,&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;I have studied how to set up for I2C for Srf08 sensor. however, I dont know how to write it to the LPC1758 I2C controller.&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;From the I2C Example I used in MCB1700 example code bundle. I dont understand how to the step below in the i2cmst.c &lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;Can anyone share their experience on that to help solve the problem please?&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt; &lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;Here is the steps for the I2C to write and read to sensor&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;write to sensor&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;i2c_start();&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // send start sequence&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;i2c_tx(0xE0);&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // SRF08 I2C address with R/W bit clear&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;i2c_tx(0x00);&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // SRF08 command register address&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;i2c_tx(0x51);&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // command to start ranging in cm&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;i2c_stop();&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // send stop sequence&lt;/SPAN&gt;&lt;BR /&gt;&lt;BR /&gt;&lt;SPAN&gt;read from sensor&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;i2c_start();&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // send start sequence&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;i2c_tx(0xE0);&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // SRF08 I2C address with R/W bit clear&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;i2c_tx(0x01);&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // SRF08 light sensor register address&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;i2c_start();&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // send a restart sequence&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;i2c_tx(0xE1);&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // SRF08 I2C address with R/W bit set&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;lightsensor = i2c_rx(1);&amp;nbsp; // get light sensor and send acknowledge. Internal register address will increment automatically.&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;rangehigh = i2c_rx(1);&amp;nbsp;&amp;nbsp;&amp;nbsp; // get the high byte of the range and send acknowledge.&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;rangelow = i2c_rx(0);&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // get low byte of the range - note we don't acknowledge the last byte.&lt;/SPAN&gt;&lt;BR /&gt;&lt;SPAN&gt;i2c_stop();&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; // send stop sequence&lt;/SPAN&gt;&lt;BR /&gt;&lt;BR /&gt;&lt;/BODY&gt;&lt;/HTML&gt;</description>
      <pubDate>Wed, 15 Jun 2016 17:29:46 GMT</pubDate>
      <guid>https://community.nxp.com/t5/LPC-Microcontrollers/I2C-code-problem-with-Srf08-ultrasonic-sensors-with-LPC1758/m-p/517822#M2363</guid>
      <dc:creator>lpcware</dc:creator>
      <dc:date>2016-06-15T17:29:46Z</dc:date>
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