Forum >Motor electrical noise, EMI
Motor electrical noise, EMI
Account cancelled 2017-05-14 09:07:23 2957 Views1 Replies I have a Pirate-4WD Mobile Platform (SKU:ROB0003) which can use 4 TT Geared Motors with Back Shaft (SKU:FIT0016) and the DFRduino Romeo-All in one Controller V1.1(SKU:DFR0004).
I had a simple project in mind and so I removed 2 of the motors and replaced the 2 associated wheels with a single, front undriven, free rotating (in the vertical axis) wheel. I then connected the system to an MPU6050 accelerometer / gyroscopic board which communicated with the Romeo via I2C.
The electrical noise from the 2 motors just killed the signals from the MPU6050 and the running of the Romeo software to the point where the loop() function would stop. In fact, when the motors run, the brush arcing is so bad as to create a very noticeable amount of ozone. The communication lines to the MPU6050 were about 3 inches long.
I tried twisting the motor power leads, applying "happy caps", i.e., 0.1 uF capacitors, on the motors, all to no avail. I finally modified the MPU6050 board and plugged it directly into the Romeo's analog header and that will work about 60% of the time, i.e., the loop() function would continue and data could be processed from the MPU6050.
I am surprised how electrically noisy these motors are.
Is there some way to handle the electrical noise from the motors?
Thanks.
I had a simple project in mind and so I removed 2 of the motors and replaced the 2 associated wheels with a single, front undriven, free rotating (in the vertical axis) wheel. I then connected the system to an MPU6050 accelerometer / gyroscopic board which communicated with the Romeo via I2C.
The electrical noise from the 2 motors just killed the signals from the MPU6050 and the running of the Romeo software to the point where the loop() function would stop. In fact, when the motors run, the brush arcing is so bad as to create a very noticeable amount of ozone. The communication lines to the MPU6050 were about 3 inches long.
I tried twisting the motor power leads, applying "happy caps", i.e., 0.1 uF capacitors, on the motors, all to no avail. I finally modified the MPU6050 board and plugged it directly into the Romeo's analog header and that will work about 60% of the time, i.e., the loop() function would continue and data could be processed from the MPU6050.
I am surprised how electrically noisy these motors are.
Is there some way to handle the electrical noise from the motors?
Thanks.
2017-05-22 12:55:12 For electric noise caps help, but there is also magnetic fields and all cables (forming loops) will pick these up...
The best is to stay away from bad motors, personally I had bad experiences with these "plastic" motors. For small projects I use micrometal motors (pololu IIRC) and they work better but not perfect. I am now trying these:https://www.dfrobot.com/wiki/index.php/FIT0441_Brushless_DC_Motor_with_Encoder_12V_159RPM
I hope they will perform better. I will even test them with an oscilloscope to see how much they interfere on cables, we'll see.
What I mean: it is a real trouble and not so easy to deal with. I hope others will help more than I did
HTH manufwi
The best is to stay away from bad motors, personally I had bad experiences with these "plastic" motors. For small projects I use micrometal motors (pololu IIRC) and they work better but not perfect. I am now trying these:https://www.dfrobot.com/wiki/index.php/FIT0441_Brushless_DC_Motor_with_Encoder_12V_159RPM
I hope they will perform better. I will even test them with an oscilloscope to see how much they interfere on cables, we'll see.
What I mean: it is a real trouble and not so easy to deal with. I hope others will help more than I did
HTH
manufwi 