How to read FT-IMU when FT is read with embObjMultipleFTsensors

[GiulioRomualdi]

I would like to read the IMU data coming from an FT which is loaded with the embObjMultipleFTsensors device (because we have two FTs connected to the same ems).

Thanks

[triccyx]

You should use service eomn_serv_AS_inertials3. Take a look at:
https://github.com/robotology/robots-configuration/blob/master/iCubTemplates/iCubTemplateV5_0/hardware/inertials/body_part-ebX-IMU.xml
Thanks to @marcoaccame that can give you more information (if you need it) in the next few days.
@davidetome

[marcoaccame]

This service is already used in some robots in IIT:

• https://github.com/robotology/robots-configuration/blob/master/iCubGenova04/hardware/inertials/right_leg-eb9-IMU.xml
• https://github.com/robotology/robots-configuration/blob/master/iCubGenova09/hardware/inertials/head-inertial.xmlhttps://github.com/robotology/robots-configuration/blob/master/iCubGenova09/hardware/inertials/head-inertial.xml

and can be used with multiple boards even of various type.

[GiulioRomualdi]

Thank you @marcoaccame and @triccyx for your answers! They are pretty helpful.
I would like to add some additional comments for the next one that is going to enable these services on a robot.

A working set of configuration files for iCubGenova09 can be found at this PR ami-iit/robots-configuration#17

I will analyze only the configuration files for the left foot FTs. On iCubGenova09 two FTs are connected to the same ems. The specific files I will analyze can be found at this commit: ami-iit/robots-configuration@c51eed1

First of all, I had to add a file related to the physical device embObjIMU. The device uses the eomn_serv_AS_inertials3 as mentioned by @triccyx and @marcoaccame.
I stored the device iCubGenova09/hardware/inertials/left_leg-eb8-IMU.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE devices PUBLIC "-//YARP//DTD yarprobotinterface 3.0//EN" "http://www.yarp.it/DTD/yarprobotinterfaceV3.0.dtd">

<device xmlns:xi="http://www.w3.org/2001/XInclude" name="left_leg-eb8-imu" type="embObjIMU">
<xi:include href="../../general.xml" />
<xi:include href="../../hardware/electronics/left_leg-eb8-j3_5-eln.xml" />

<group name="SERVICE">
  <param name="type"> eomn_serv_AS_inertials3 </param>

  <group name="PROPERTIES">

    <group name="CANBOARDS">
      <param name="type">             eobrd_strain2           </param>
      <group name="PROTOCOL">
        <param name="major">            0                   </param>
        <param name="minor">            0                   </param>
      </group>

      <group name="FIRMWARE">
        <param name="major">            0                   </param>
        <param name="minor">            0                   </param>
        <param name="build">            0                   </param>
      </group>
    </group>

    <group name="SENSORS">
      <param name="id">       l_foot_rear_ft_acc    l_foot_rear_ft_gyro    l_foot_rear_ft_eul    l_foot_rear_ft_mag    l_foot_rear_ft_stat   l_foot_front_ft_acc    l_foot_front_ft_gyro    l_foot_front_ft_eul    l_foot_front_ft_mag    l_foot_front_ft_stat</param>
      <param name="type">     eoas_imu_acc             eoas_imu_gyr              eoas_imu_eul             eoas_imu_mag             eoas_imu_status   eoas_imu_acc             eoas_imu_gyr              eoas_imu_eul             eoas_imu_mag             eoas_imu_status</param>
      <param name="boardType">  strain2       strain2      strain2       strain2        strain2   strain2       strain2      strain2       strain2        strain2</param>
      <param name="location">  CAN2:13       CAN2:13      CAN2:13       CAN2:13        CAN2:13    CAN2:14       CAN2:14      CAN2:14       CAN2:14        CAN2:14</param>
    </group>

  </group>

  <group name="SETTINGS">
    <param name="acquisitionRate">      50      </param>
    <param name="enabledSensors">       l_foot_rear_ft_acc    l_foot_rear_ft_gyro    l_foot_rear_ft_eul    l_foot_rear_ft_mag    l_foot_rear_ft_stat l_foot_front_ft_acc    l_foot_front_ft_gyro    l_foot_front_ft_eul    l_foot_front_ft_mag    l_foot_front_ft_stat</param>
  </group>
</group>

</device>

Once the hardware device has been defined I also added the associated server wrapper. The file is stored in iCubGenova09/wrappers/inertials/left_foot-IMU_wrapper.xml Thanks to this wrapper it will be possible to get the gyro Euler acc magnetometer and status readouts from the IMU mounted on the FTs in the port /icub/left_foot/imu/measurements:o
It is important to notice that the element of the attributeSetOfInertials (i.e., <elem name="SetOfInertials">left_leg-eb8-imu </elem>) must be the same of the name of the hardware device , i.e., <device xmlns:xi="http://www.w3.org/2001/XInclude" name="left_leg-eb8-imu" type="embObjIMU">

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE devices PUBLIC "-//YARP//DTD yarprobotinterface 3.0//EN" "http://www.yarp.it/DTD/yarprobotinterfaceV3.0.dtd">

<device xmlns:xi="http://www.w3.org/2001/XInclude" name="left_foot-imu_wrapper" type="multipleanalogsensorsserver">
<param name="period">       10                  </param>
<param name="name">     /icub/left_foot/imu     </param>

<action phase="startup" level="5" type="attach">
  <paramlist name="networks">
    <!-- The name of the element can be any string (we use SetOfInertials to better express its nature).
         Its value must match the device name in the corresponding body_part-jx_y-inertials.xml file
         or in body_part-ebX-inertials.xml -->
    <elem name="SetOfInertials">left_leg-eb8-imu </elem>
  </paramlist>
</action>

<action phase="shutdown" level="5" type="detach" />
</device>

I finally added the the following lines in the main xml file opened run by the robotinterface

<xi:include href="hardware/inertials/left_leg-eb8-IMU.xml" />
<xi:include href="wrappers/inertials/left_foot-IMU_wrapper.xml" />