hello
I am trying to control the DC motor through the TFC-shield.
In the TFC-shield, there is a IFB pin (as I know, This pin represent the armature current over 375 . am I right?)
Here is my questions,
1. Can I PID control the DC motor with just known about armature current? I have to measure the angular velocity of the tire as far as I know .
because armature current and angular velocity are not simply related. so In my opinion It is hard to control the DC motor using armature current .
2. If I can, then how to use this..?
thanks.
Solved! Go to Solution.
I believe that is a current feedback pin. According to the datasheet: "The load current feedback output provides ground referenced 0.24% of the high side output current. (Tie to GND through a resistor if not used.)"
You could measure the current through each motor with this pin, but I don't think that is very useful in controlling the motor--a speed sensor on the wheels is probably more useful. The schematics for the board are here: https://community.freescale.com/servlet/JiveServlet/download/93914-26-257650/FRDM-TFC-REVB-BUILD_PAC...
From that, you will see that you enable the H-bridge thru H-Bridge-Enable connected to PTE21 and control the speeds of each motor by applying PWM to H-Bridge-A-IN1/2 (PTC3 and PTC4) and H-Bridge-B-IN1/2 (PTC1 and PTC2).
Good Luck!
Bob
I believe that is a current feedback pin. According to the datasheet: "The load current feedback output provides ground referenced 0.24% of the high side output current. (Tie to GND through a resistor if not used.)"
You could measure the current through each motor with this pin, but I don't think that is very useful in controlling the motor--a speed sensor on the wheels is probably more useful. The schematics for the board are here: https://community.freescale.com/servlet/JiveServlet/download/93914-26-257650/FRDM-TFC-REVB-BUILD_PAC...
From that, you will see that you enable the H-bridge thru H-Bridge-Enable connected to PTE21 and control the speeds of each motor by applying PWM to H-Bridge-A-IN1/2 (PTC3 and PTC4) and H-Bridge-B-IN1/2 (PTC1 and PTC2).
Good Luck!
Bob
GregoryCAMUZAT johnmc(test) any idea about this?