k1v1116
Newbie level 3
I'm working on a stepper motor driver, most of the control will be handled by a PIC most likely a 16f887.
I want to simplify control of the H-bridge switches to use fewer pins and make programming easier for the PIC so I came up with the circuit below.
The H-bridge needs only a few signals, direction, decay mode(fast / slow) and a pwm signal from the chopper(not included in the circuit below). This design will have microstepping so output from a r-2r or DAC will provide the Vref for the chopper comparator.
basically I have a 3 TO 8 LINE DECODER (M74HC238B1) decoding the 8 possible combinations of the 3 control signals and then ORing them into the correct switch combinations to control the H-bridge.
Please take a look at the circuit below and point out any flaws, or improvements that could be made.
I want to simplify control of the H-bridge switches to use fewer pins and make programming easier for the PIC so I came up with the circuit below.
The H-bridge needs only a few signals, direction, decay mode(fast / slow) and a pwm signal from the chopper(not included in the circuit below). This design will have microstepping so output from a r-2r or DAC will provide the Vref for the chopper comparator.
basically I have a 3 TO 8 LINE DECODER (M74HC238B1) decoding the 8 possible combinations of the 3 control signals and then ORing them into the correct switch combinations to control the H-bridge.
Please take a look at the circuit below and point out any flaws, or improvements that could be made.
