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* Detailed Description:
* Sensor board OM11057A which includes two PCF8885 circuits is connected
* to MPC5748G via I2C. MPC5748G continuously reads the state of touch sensors
* and the state is shown on LED diodes which are driven by I2C circuit PCA9535.
*
* Used I2C driver: https://community.freescale.com/docs/DOC-330972
*
* Touch sensor board (page 9 and 10):
* http://www.nxp.com/documents/user_manual/UM10505.pdf
*
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*
* Connection:
*
* Connect I2C bus (I2C_2 on MPC5748G) to sensor board:
* I2C_SCL: P24-33 (pin PE9) on MPC574XG-MB to K3-1 on OM11057A
* I2C_SDA: P24-35 (pin PE8) on MPC574XG-MB to K3-13 on OM11057A
* Note: use two pull-up resistors on I2C signals (pulled to 3.3V).
* The value should be 3k3 - 10k
*
* Connect power supply from MPC574XG-MB to OM11057A:
* GND: P24-2 on MPC574XG-MB to K3-7 on OM11057A
* 3.3V: P24-1 on MPC574XG-MB to K3-9 on OM11057A
*
* Connect SLEEP pins of both PCF8885 to GND (this will ensure that sleep mode
* is not entered):
* SLEEP1: K3-11 to K2-3 (both on OM11057A)
* SLEEP2: K1-6 to K1-8 (both on OM11057A)
*
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* Sensor board: OM11057A
* http://www.nxp.com/documents/user_manual/UM10505.pdf
* Test HW: MPC574XG-324DS Rev.A + MPC574XG-MB Rev.C
* MCU: PPC5748GMMN6A 1N81M
* Fsys: 160 MHz PLL
* Debugger: Lauterbach Trace32
* Target: internal_FLASH
*
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