Hi there!
I'm having a nightmare with a motor and an optical encoder,
When I test the setup with the motor I want to use (a planetary 12V DC, precious metal brushes), the optical encoder seems to generate additional false pulses whenever the motor is moving, so it creeps and looses its position very quickly.
The motor draws ~800ma at stall, but it seriously interferes with the encoder/uC communication even when rotating unloaded, where current draw will be <100ma I believe.
I have another, cheaper and dirtier 12V motor which is 50% more powerful, and it exhibits ZERO encoder errors/ creep when wired into the same circuit, even when moving very quickly. If I turn the encoder by hand, even very fast moves won't confuse it, the software side is working very well.
So, I assume that these false Encoder pulses generated when the DC motor is running are a result of EMI? This is my first serious encounter with EMI, I don't know the place to start looking in my circuit (see attached). Each IC is bypassed. I have tried with 1k and 10k pull-up resistors on the Encoder outputs, as it doesn't have them internally.
Any tips on where to start my EMI reduction journey, or have I missed something else entirely?
Jimbo
I'm having a nightmare with a motor and an optical encoder,
When I test the setup with the motor I want to use (a planetary 12V DC, precious metal brushes), the optical encoder seems to generate additional false pulses whenever the motor is moving, so it creeps and looses its position very quickly.
The motor draws ~800ma at stall, but it seriously interferes with the encoder/uC communication even when rotating unloaded, where current draw will be <100ma I believe.
I have another, cheaper and dirtier 12V motor which is 50% more powerful, and it exhibits ZERO encoder errors/ creep when wired into the same circuit, even when moving very quickly. If I turn the encoder by hand, even very fast moves won't confuse it, the software side is working very well.
So, I assume that these false Encoder pulses generated when the DC motor is running are a result of EMI? This is my first serious encounter with EMI, I don't know the place to start looking in my circuit (see attached). Each IC is bypassed. I have tried with 1k and 10k pull-up resistors on the Encoder outputs, as it doesn't have them internally.
Any tips on where to start my EMI reduction journey, or have I missed something else entirely?
Jimbo