AD5700 and Arduino Mega 2560

Hi!

I need help interfacing an AD5700 evaluation board with an Arduino Mega 2560 in order to acquire data from a differential pressure transducer. I am beginner with electronics and it is the first time I have to use the HART protocol. 

I have attached the data sheet for the differential pressure transducer, in case it is needed.

DTR.APC.APR.ALW.HART.pdf
  • Hi DaveC,

     

    You can choose between the two connections on the figure below for the interface of AD5700 to the pressure transmitter.

    • Option A on the left uses an external filter to the ADC_IP for the 4-20mA+HART signal from the transmitter. The filter provides additional protection from the high voltage loop supply.
    • Option B on the right is to connect the 4-20mA+HART signal directly to the HART_IN pin. This option uses an internal band pass filter which will allow you to save board space.

    The ADuc7060 MCU on the diagram will be replaced by the Arduino Mega 2560. Use UART protocol to communicate from Arduino to AD5700.

    Details on the configuration pins is discussed on the AD5700 data sheet, specifically on Table 7.

     

    Best regards,

    Rainier

     

  • Hi Rainier,

    Thank you for answering my question. I have unfortunately fried the IC on my evaluation board, by accidentally plugging the power supply + into the REF pin. It's very cheap to replace the IC, in any case, but before bricking my board I've had little success with getting any readings to my Arduino. I've used the default internal pass filter and connected the communicator wires to HART in and HART out according to the DPT datasheet (see figure below), and on the Arduino RXD to Rx1, TXD to Tx1, and GND to the Arduino's GND, but the serial monitor was silent.

    Best regards,

    Dan S.

  • Hi Dan S,

     

    In addition to the RXD and TXD pins, you also need to control the /RTS and monitor the CD pins of the AD5700. You can do these by using the GPIO pins of the Arduino.

    If possible, can you provide more details regarding your setup? perhaps your schematic or simplified block diagram which details all the connection from the Arduino to AD5700 to DPT.

     

    Best regards,

    Rainier