I'm trying to design a circuit in order to use the TB67H303 motor driver with the ATMEGA328p and the i2c protocol by using the PCA9685 controller.

I never used the TB67H303 and the PCA9685 chips before, so I would like to know if I made errors in my scheme.

By considering the TB67H303 datasheet, as reported in the Application Circuit (page 16) for Direct PWM mode, I tried to connect:

  • pin 3 SELECT to LOW
  • pin 7 STBY to the pin 6 of the PCA9685
  • pins 8, 9 and 22 to pins 7, 8, 9 of the PCA9685 for motor control
  • pin 5 Vref to pin 2 SGND as reported in the application circuit
  • pin RSA, RSB, PGNDA, PGNDB to GND(12V)
  • pin 6 VCC to +12V

enter image description here

I connected Pins A0 to A5 of the PCA9685 to a 5 way header so I can set the address by short-circuiting the related pins to +5V. I also connected pin 23 OE and pin 25 EXTCLK to GND. Is it correct?

This is my circuit, I hope it doesn't have too much errors :)

Thank you for your help! This is my wiring -> enter image description here

  • 1
    \$\begingroup\$ We discourage broad, open-ended design review questions here on EE.SE, because the answer(s) tend to become long strings of unrelated edits and/or comments. While this might help you with your immediate problems, it is of no value to the site overall. We DO allow design review questions in which you explain your choices and then focus on a few points about which you still have doubts. To get a better feel of what is or is not acceptable, search for "design review" on the meta site. \$\endgroup\$ – Dave Tweed Jun 29 '19 at 20:23
  • \$\begingroup\$ Hello, I'm asking only about the wiring for the i2c and the motor driver even if I posted my full circuit. I would like to focus only on two these components since I'm not use if it is correct how I connected all the pins. Isn't this ok with the design rules? \$\endgroup\$ – Marcus Barnet Jun 29 '19 at 22:23
  • \$\begingroup\$ I edited my question by removing the whole circuit, now I'm only asking for the wiring of the i2c controller and the driver. I hope it is ok now. \$\endgroup\$ – Marcus Barnet Jun 30 '19 at 11:20
  • \$\begingroup\$ Is my question too hard? Nobody can help me about the wiring? \$\endgroup\$ – Marcus Barnet Jul 3 '19 at 11:44

5 Minute Design Review

  • Why is DC 2200uF cap before diode instead of after?

  • verify is Ft232R correct for pin numbers and connected unused handshaking inputs to the correct level.

  • why is there no UVDC detection or DC OK?
  • How will you test this to debug? With an external loop back? Self test? What happens when something fails ? where do you start looking? Or do you want it to tell you the status? we call this DFT !

How will you isolate radiated and conducted ground current noise? What dV/dt , dI/dt and CMRR do you expect? For example crosstalk to RC1,2,3,4.

  • \$\begingroup\$ Thank you, I'm moving the cap after the diode. I changed the scheme in order to focus only on the i2c and the motor driver since I'm not sure if their wiring is ok. Hope you can help me, thank you \$\endgroup\$ – Marcus Barnet Jun 30 '19 at 11:20

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