ADuCM4050 SensorStrobe inputs

Hi, 

I need to configure RTC1 and its SensorStrobe channel to interface ADXL372,  ADXL362 or anything similar.

1)   One INT pin of the accelerometer will be used to provide measurement pulse. So it should be connected to one of the RTC1_SSn pin, is that correct?
2)    Second INT pin will be used to monitor when the MCU should read acquired data from accelerometer's FIFO. On page 21-8 of ADuCM4050 hardware manual, there is written that I can pick 3 out of 8 available GPIOs to act as SensorStrobe inputs, but there is no mention about which specific pins can I pick... 

Also in adi_rtc_config.h on lines 359-360:

* GPMUX0/1.SSxGPINySEL 3’b000 3’b001 3’b010 3’b011 3’b100 3’b101 3’b110 3’b111
* RTCSSxGPIny                       p0[12]   p2[0]   p0[9]     p0[8]    p1[13]  p1[2]    p2[7]   p2[9]

Does that mean that pins P0_12, P2_00, P0_09 etc. can be used as SensorStrobe inputs? Do I have to set their function in GPIO multiplex?

3)   Is there any example of complete SensorStrobe functionality?

Thanks & regards

Tomas

  • 0
    •  Analog Employees 
    on Jul 25, 2017 7:15 PM

    Hi ,

     

    A typical connection between ADuCM4050 and ADXL362 would be:

    • Connect SensorStrobe pin on the MCU (output) with INT2 on the accelerometer (input).

            Purpose: MCU provides the trigger when the accelerometer has to acquire data

    • Connect INT1 on the accelerometer (output) with any external interrupt pin (SYS_WAKEx) on the MCU (input)

            Purpose: Accelerometer wakes up the MCU when FIFO almost full (watermark)

     

    The Input Sampling capability mentioned on page 21-8 of the Hardware Reference Manual is intended to monitor up to three GPIO inputs from an external device, which can be sampled based on the output pulse sent to that external device. Each SensorStrobe channel can be configured to interrupt the ADuCM4050 MCU when a specific activity is detected on these GPIO inputs, e.g. sensor states like FIFO full, switch open, threshold crossed…. It is very useful when different inputs need to be analyzed at the same time. In the case that you describe, as it is only one device being monitored it is recommended to use an external interrupt pin (easier to configure).

     

    Right now the information with respect the GPIOs that might be sampled is missing on the Hardware Reference Manual, as you notice. We will include all the information on the next version. As you correctly pointed, those 8 GPIOs are P0.12, P2.0, P0.9, P0.8, P1.13, P1.2, P2.7 and P2.9 (to be configured as 0, 1, 2 …7 in SSxGPINySEL bitfields the RTC_GPMUX0 and RTC_GPMUX1 registers).

     

    Currently there is no released example code showing the input sampling and input compare capabilities.

     

    Kind regards,

    Monica