Other Parts Discussed in Thread: MCF8329A,
Tool/software:
Hello TI Engineers,
I am currently working with the MCF8329A gate driver to run a BLDC motor. My goal is to operate the motor using PWM control, but in order to identify a stable parameter set for closed-loop operation, I am first testing the motor via I²C control.
The issue I am facing is that a parameter set which allows the motor to run smoothly in one attempt will often fail to work the next time. Instead of running, the device reports a “Loss of Sync” error.
For example:
-
If I set A1 = 0.005 Hz and A2 = 0.025 Hz, the motor may start and run correctly once.
-
However, if I attempt to run the motor again with the exact same parameters, it fails with “Loss of Sync.”
-
Strangely, changing the values (e.g., A1 = 0.1 Hz and A2 = 0.25 Hz) or any other random values sometimes makes it work again.
This behavior has left me confused, since I cannot determine which acceleration values (A1, A2) are actually correct for consistent startup. I have attached a video to demonstrate the issue, and I would appreciate your feedback.
In addition, I noticed another issue related to register settings. I saved a JSON register file from a working configuration. However, when I try to reload this same file later (File → Load Register), the motor does not run and instead shows a “Lock Current Limit” error. This happens even though the exact same file had worked before. I have attached the JSON file for your reference.
For context, here are the known specifications of my motor:
-
Mechanical speed: 16,000 rpm
-
Electrical frequency: 533 Hz
-
Resistance: 0.232 Ω
-
Inductance: 192 µH
-
Current rating: I have no idea of any current related parameters of my motor as I dont have access to datasheet or any other info. what i know is that this motor will take upto 5A in closed loop. startup can go upto 8 -10A. Nothing more than this.
At the moment, I am unsure which parameters are correct and why the same settings behave inconsistently. Any guidance on how to stabilize the configuration and avoid these errors would be greatly appreciated.
Json file: {
"signature": "oneui-register-data",
"data": [
[
{
"idx": 0,
"id": "isd_config",
"value": "0x00000000"
},
{
"idx": 1,
"id": "motor_startup1",
"value": "0x07000000"
},
{
"idx": 2,
"id": "motor_startup2",
"value": "0x0010A000"
},
{
"idx": 3,
"id": "closed_loop1",
"value": "0x00016000"
},
{
"idx": 4,
"id": "closed_loop2",
"value": "0x00000028"
},
{
"idx": 5,
"id": "closed_loop3",
"value": "0x00000000"
},
{
"idx": 6,
"id": "closed_loop4",
"value": "0x00000000"
},
{
"idx": 7,
"id": "const_speed",
"value": "0x00000000"
},
{
"idx": 8,
"id": "const_pwr",
"value": "0x10A80000"
},
{
"idx": 9,
"id": "150_deg_two_ph_profile",
"value": "0x00000000"
},
{
"idx": 10,
"id": "150_deg_three_ph_profile",
"value": "0x00000000"
},
{
"idx": 11,
"id": "ref_profiles1",
"value": "0x00000000"
},
{
"idx": 12,
"id": "ref_profiles2",
"value": "0x00000000"
},
{
"idx": 13,
"id": "ref_profiles3",
"value": "0x00000000"
},
{
"idx": 14,
"id": "ref_profiles4",
"value": "0x00000000"
},
{
"idx": 15,
"id": "ref_profiles5",
"value": "0x00000000"
},
{
"idx": 16,
"id": "ref_profiles6",
"value": "0x00000000"
}
],
[
{
"idx": 0,
"id": "algo_ctrl1",
"value": "0x00000000"
},
{
"idx": 1,
"id": "device_ctrl",
"value": "0x00000000"
}
],
[
{
"idx": 0,
"id": "ana_trim3",
"value": "0x00000000"
},
{
"idx": 1,
"id": "ana_trim4",
"value": "0x00000000"
},
{
"idx": 2,
"id": "ana_trim5",
"value": "0x00000000"
},
{
"idx": 3,
"id": "ana_trim6",
"value": "0x00000000"
},
{
"idx": 4,
"id": "ana_trim7",
"value": "0x00000000"
},
{
"idx": 5,
"id": "ana_trim8",
"value": "0x00000000"
},
{
"idx": 6,
"id": "ana_trim9",
"value": "0x00000000"
},
{
"idx": 7,
"id": "ana_trim10",
"value": "0x00000000"
}
],
[
{
"idx": 0,
"id": "fault_config1",
"value": "0x00000000"
},
{
"idx": 1,
"id": "fault_config2",
"value": "0x03000000"
}
],
[
{
"idx": 0,
"id": "gate_driver_fault_status",
"value": "0x00000000"
},
{
"idx": 1,
"id": "controller_fault_status",
"value": "0x00000000"
}
],
[
{
"idx": 0,
"id": "gd_config1",
"value": "0x00000000"
},
{
"idx": 1,
"id": "gd_config2",
"value": "0x00000000"
}
],
[
{
"idx": 0,
"id": "pin_config1",
"value": "0x00000002"
},
{
"idx": 1,
"id": "pin_config2",
"value": "0x00000000"
},
{
"idx": 2,
"id": "device_config",
"value": "0x00000400"
}
],
[
{
"idx": 0,
"id": "sys_status1",
"value": "0x00000000"
},
{
"idx": 1,
"id": "sys_status2",
"value": "0x00000000"
},
{
"idx": 2,
"id": "sys_status3",
"value": "0x00000000"
}
]
]
}
