I2tLimitException

Support & Troubleshooting Software
1

I have a simple loop where I read IMU, loadcell (through actpack), and actuator data and write to logs.

I get these errors related to thermals curves, seemingly at random times.

Example 1:

[2026-04-07 14:59:54,643] INFO: Time: 30.041; Ankle: +0.08; Knee: +0.09; Fz: -5; Roll: -0.59; Latency: 13.5ms;

[2026-04-07 14:59:54,666] INFO: Time: 30.055; Ankle: +0.08; Knee: +0.09; Fz: +0; Roll: -0.59; Latency: 23.0ms;

[2026-04-07 14:59:54,685] INFO: Time: 30.078; Ankle: +0.08; Knee: +0.09; Fz: -0; Roll: -0.59; Latency: 18.2ms;

[2026-04-07 14:59:54,704] INFO: Time: 30.097; Ankle: +0.08; Knee: +0.09; Fz: -3; Roll: -0.59; Latency: 18.1ms;

[2026-04-07 14:59:54,720] INFO: Time: 30.116; Ankle: +0.08; Knee: +0.09; Fz: -3; Roll: -0.59; Latency: 15.3ms;

[2026-04-07 14:59:54,720] ERROR: [KNEE] I2t limit exceeded. Current: 0.0 mA. 

opensourceleg.extras.safety.safety.I2tLimitException: Dephy Actpack I2t limit exceeded. Exiting.

Example 2:

[2026-04-07 15:06:28,564] INFO: Time: 138.147; Ankle: +0.23; Knee: +0.34; Fz: +3; Roll: -0.52; Latency: 18.1ms;

[2026-04-07 15:06:28,580] INFO: Time: 138.165; Ankle: +0.23; Knee: +0.34; Fz: +3; Roll: -0.52; Latency: 14.5ms;

[2026-04-07 15:06:28,580] ERROR: [ANKLE] I2t limit exceeded. Current: 0.0 mA. 

opensourceleg.extras.safety.safety.I2tLimitException: Dephy Actpack I2t limit exceeded. Exiting.
2

I have also observed this behavior when running this example.

(opensourceleg/tutorials/actuators/dephy/reading_multiple_actuators.py)

It occurs at random times. For example, in another session, it was working fine for 10 minutes before I manually stopped.

(By the way, the reported currents don’t make sense. The motors are powered by the RPi’s USB.)

Example output log:

Output log:

[2026-04-08 05:02:04,431] INFO: Time: 46.49; Motor Current 01: 2.00; Motor Current 02: -5.00;

[2026-04-08 05:02:04,436] INFO: Time: 46.49; Motor Current 01: 3.00; Motor Current 02: -4.00;

[2026-04-08 05:02:04,440] INFO: Time: 46.50; Motor Current 01: 3.00; Motor Current 02: -1.00;

[2026-04-08 05:02:04,444] INFO: Time: 46.50; Motor Current 01: 4.00; Motor Current 02: -3.00;

[2026-04-08 05:02:04,448] INFO: Time: 46.51; Motor Current 01: 1.00; Motor Current 02: -5.00;

[2026-04-08 05:02:04,452] INFO: Time: 46.51; Motor Current 01: 0.00; Motor Current 02: -4.00;

[2026-04-08 05:02:04,456] INFO: Time: 46.51; Motor Current 01: 2.00; Motor Current 02: -6.00;

[2026-04-08 05:02:04,460] ERROR: [DEPHYACTUATOR] I2t limit exceeded. Current: 1024.0 mA. 

[2026-04-08 05:02:04,460] DEBUG: [DephyActuator]  Exiting Voltage control mode.

[2026-04-08 05:02:05,166] DEBUG: [DephyActuator]  Exiting Voltage control mode.
3

Terminal output corresponding to the log in the previous post:



(OSLvenv) pressureheadless@pressure:~/osl_lib_test $ python3 reading_multiple_actuators.py 8.00;;
Warning: unable to access S3 to obtain updated available versions.
Warning: using firmware version information from: 57 days ago.
To update, connect to the internet and re-run this function.
Using firmware version: 7.2.0
Using library file: /home/pressureheadless/.dephy/precompiled_c_libs/7.2.0/pi_64bit/libfx_plan_stack.so
Warning: unable to access S3 to obtain updated available versions.
Warning: using firmware version information from: 57 days ago.
To update, connect to the internet and re-run this function.
Using firmware version: 7.2.0
Using library file: /home/pressureheadless/.dephy/precompiled_c_libs/7.2.0/pi_64bit/libfx_plan_stack.so
opensourceleg.extras.safety.safety.I2tLimitException: Dephy Actpack I2t limit exceeded. Exiting.