Motors and Sensors - Forum https://theopenexo.nau.edu/community/motors-and-sensors/ Discussion Board en-US Thu, 10 Sep 2026 10:44:45 +0000 wpForo 60 Activation of the PID function https://theopenexo.nau.edu/community/motors-and-sensors/activation-of-the-pid-function/ Thu, 02 Apr 2026 19:03:17 +0000 Is it mandatory to install a torque sensor to enable PID control？

]]> Motors and Sensors wuyang https://theopenexo.nau.edu/community/motors-and-sensors/activation-of-the-pid-function/ Using FSR, but the motor torque is not controlled https://theopenexo.nau.edu/community/motors-and-sensors/using-fsr-but-the-motor-torque-is-not-controlled/ Mon, 23 Mar 2026 03:20:29 +0000 Dear Developer,

We are trying to control a motor using FSR with the original v2.0 code. We have set the torque to 0.5 N·m via the SD card. However, when controlling the motor through the GUI, the output torque becomes extremely large and uncontrollable. Even after increasing the current limit of the adjustable power supply from 24V/2A to 24V/5A, the current hits the upper limit instantly. Could you please advise on how to resolve this issue? Thank you very much for your help.

]]> Motors and Sensors Huang_Enghong https://theopenexo.nau.edu/community/motors-and-sensors/using-fsr-but-the-motor-torque-is-not-controlled/ MIT mode？ https://theopenexo.nau.edu/community/motors-and-sensors/mit-mode%ef%bc%9f/ Sun, 01 Feb 2026 14:06:46 +0000
Hello, I’d like to confirm whether the motor is operating in MIT mode when the exoskeleton is running.
 
Per the user manual for the AK60v1.1 motor, a motor configured to MIT mode via the host computer requires a specific CAN command to be sent to it before it can be activated. The relevant excerpt from the AK60v1.1 motor’s user manual is as follows:


Special CAN Commands
 
  • Enter motor control mode: {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0XFC}
  • Exit motor control mode: {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0XFD}
  • Set the motor’s current position as the zero point: {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0XFE}
 
Note: When controlling the motor via CAN communication, you must enter the motor control mode first!



However, I don’t seem to have found this specific CAN command in the OpenExo code. When I was replicating this project, the motor failed to rotate. Do you think this might be the underlying issue? I look forward to your response. Thank you!
 
 
]]> Motors and Sensors wuyang https://theopenexo.nau.edu/community/motors-and-sensors/mit-mode%ef%bc%9f/ Connecting both the torque sensor and FSR to PCB https://theopenexo.nau.edu/community/motors-and-sensors/connecting-both-the-torque-sensor-and-fsr-to-pcb/ Fri, 23 Jan 2026 22:29:45 +0000 We are making the right side ankle. Using the torque sensor from Biomotum and the FSR, how do they both connect to the PCB board? Since the torque sensor is already using the 8-pin IDC on the right side of the PCB, will the FSR connect to the 8-pin on the left side of the board?

]]> Motors and Sensors Delta https://theopenexo.nau.edu/community/motors-and-sensors/connecting-both-the-torque-sensor-and-fsr-to-pcb/ Other than the SD config file, is there any code that needs to be edited when changing the CAN ID? https://theopenexo.nau.edu/community/motors-and-sensors/other-than-the-sd-config-file-is-there-any-code-that-needs-to-be-edited-when-changing-the-can-id/ Mon, 24 Nov 2025 17:28:30 +0000 I am using the AK80-9 for the ankle. We originally set the CAN ID to the right hip, 33, to test the motor with GUI, but now when I set the CAN ID to the right ankle, 36, the motor does not run with the GUI. 1. To set the CAN ID in CubeMars, I made sure to calibrate it, then set the ID and typed "exit" before disconnecting. Then on the SD card, I went to the config file to change the Exo name to "bilateralHip" and made sure the values were set correctly in the bilateralHip section. Opening ArduinoIDE, I reuploaded the ExoCode.ino to both Teensy 4.1 and Nano. Finally, I opened the GUI to run the motor and the motor continuously runs, it doesn't pause for the 5 seconds I set in the step EXCEL file. 2. But when I repeat those steps for the Ankle using "bilateralAnkle" in the config, etc. , the green motor LED is not on, so CAN is not communicating meaning the motor does not move. 3. I then changed the CAN back to the hip to see if it still worked, and it didn't, the green LED was still not on. So my question is, is there somewhere else in the OpenExo folder, other than the SD card config file, that I'm supposed to change? And what might be wrong that the motor doesn't pause when using the GUI?

]]> Motors and Sensors delta https://theopenexo.nau.edu/community/motors-and-sensors/other-than-the-sd-config-file-is-there-any-code-that-needs-to-be-edited-when-changing-the-can-id/ torque sensor https://theopenexo.nau.edu/community/motors-and-sensors/torque-sensor/ Tue, 11 Nov 2025 12:06:20 +0000 Hello, do you have any information on torque sensor selection and fabrication? If possible, please let me know.

]]> Motors and Sensors kaka https://theopenexo.nau.edu/community/motors-and-sensors/torque-sensor/ Regarding motor replacement and possible combinations https://theopenexo.nau.edu/community/motors-and-sensors/regarding-motor-replacement-and-possible-combinations/ Sat, 01 Nov 2025 15:01:18 +0000 Hello,May I ask how many types of motor combinations are allowed in OPENEXO? (For example, two hip motors, or one hip motor and one ankle motor. I have seen relevant introductions on the wiki before, but now I forget where exactly this introduction is located.)

 

Additionally, if I do not use the CubeMars AK-series motors specified in the open-source project and instead use another type of motor that supports the CAN protocol, is it feasible? (Currently, I have one ROBSTRIDE02 motor and two ROBSTRIDE03 motors available, all of which support the CAN protocol.)

 

If feasible, what modifications are needed to replace the motors?I sincerely look forward to your reply.

 

 

]]> Motors and Sensors wuyang https://theopenexo.nau.edu/community/motors-and-sensors/regarding-motor-replacement-and-possible-combinations/ Are changes needed to be made to BOM for ankle if using AK80 motor instead? https://theopenexo.nau.edu/community/motors-and-sensors/are-changes-needed-to-be-made-to-bom-for-ankle-if-using-ak80-motor-instead/ Fri, 10 Oct 2025 03:48:28 +0000
I have a few questions regarding the Ankle BOM.
 
  1. On the BOM, there are two steel cable (3/32" and 1/16"), do I need to buy both of them? I have already bought the 1/16".
  2. I know the BOM is for AK60, but my lab is using the AK80, will the McMaster parts work for AK80 motor or will I have to make adjustments to the order?
  3. We have already purchased all the parts for the Bowden Cable assembly for AK80 motor, will those parts work on this ankle end-effector?
  4. Do we need to do any modifications on the CAD model to use AK80 motor?
]]> Motors and Sensors Delta https://theopenexo.nau.edu/community/motors-and-sensors/are-changes-needed-to-be-made-to-bom-for-ankle-if-using-ak80-motor-instead/ Is the motor torque sensor a mandatory requirement? https://theopenexo.nau.edu/community/motors-and-sensors/is-the-motor-torque-sensor-a-mandatory-requirement/ Thu, 25 Sep 2025 04:25:02 +0000

I tried uploading OpenExo.ino directly to the Teensy 4.1 and the Nano 33 BLE on the AK Board 0.5.1 11, but encountered a memory overflow issue on the Teensy. Furthermore, while reviewing the code, I noticed that motor calibration requires a torque sensor. The motors I'm currently using are two AK80-9 models for the left and right hip joints, which have already been calibrated using CubeMars Tools. I would like to know if it's possible to control these hip joint motors with the Teensy 4.1 without using a torque sensor for calibration. Is this approach feasible? I would appreciate guidance from the experts in the community on this matter.

I noticed that the calibration for the FSRs is handled quite effectively through an algorithm. Based on this experience, I'm wondering if the motor calibration performed in CubeMars Tools is sufficient, or if it is necessary to follow the method described in the paper—which involves purchasing a torque sensor and sending torque commands to the motor for calibration.

 
]]> Motors and Sensors KevinGuo https://theopenexo.nau.edu/community/motors-and-sensors/is-the-motor-torque-sensor-a-mandatory-requirement/