FDC2214EVM: I have changed these register values to set the sampling rate of FDC2214evm, but the python logging data are always in 100Hz

Hello, 

Two questions for you one this: 

1. When you are reading data through python, how are you getting the data from the EVM? The streaming command or by reading the registers individually? 
2. When configuring the data graph in the GUI, what value appears in the graph configuration if you change the new data sample rate to EVM output rate? 
   1. 

Thank you, 

Justin Beigel

this function is used to read the data from evm

def read_stream(serial_port):
    stream_bytes = serial_port.read(32)
    if DEBUG_PRINT_RX_DATA:
        print("< " + ":".join("{:02x}".format(c) for c in stream_bytes))
    (error_code, raw_ch0, raw_ch1, raw_ch2, raw_ch3) = struct.unpack('>3xB2xLLLL10x', stream_bytes)
    if error_code:
        print('4- Uh-oh, command returned an error.')
    return [raw_ch0, raw_ch1, raw_ch2, raw_ch3]

and in the main function just a while loop to read and write in a csv (I have test the time writing and csv writing do not lead a long time interval, and this read_stream may cause the problem)

async def main():


    detected_ports = list(serial.tools.list_ports.grep('2047:08F8'))
    evm_serial_port = serial.Serial(detected_ports[0].device, 9600, timeout=1)


    device_id = read_reg(evm_serial_port, EVM_DEVICE_ID)
    print("device_id=%s" % (device_id))
    evm_config(evm_serial_port)


    with open('output.csv','a', newline='')as my_csv:
        csv_writer=csv.writer(my_csv)

        while True:

               raw_ = read_stream(evm_serial_port)  # get array of 4 channel measurements
               time_ = time.time()
               #print(time_,raw_)
               csv_writer.writerow([time_, raw_])
               my_csv.flush()



if __name__ == '__main__':
    asyncio.run(main())

and for the GUI graph configuration, with this 1797.028hz setting, during the streaming the evm can only achieve around 50 hz maximum output rate

Many thanks, following your suggestion I have checked those register values calculation, I think all should be fine, but now the problem is that, the python code always reads via the port communication with around 10 ms time interval. (by changing the register to let the sample ratio as 50 hz, the obtained file would still record the data at 90~100hz, but every two recorded data would be the same as a actual 50hz data reading from the evm board) 

It looks if I keep using the while loop to run the 'read_stream' function, then the 'read_stream' will always use the 'read' command every loop to communicate through the USB port, so that the 10ms time interval of data acquisition may come from here.

Is there any other code that can be used to directly stream through the evm, not by using a while loop? as you said a steaming command? any suggestion?

BR

Caoyu