ARM mbed NXP LPC1768 Development Board - 6 PWM outputs?

Robotics and electronics discussion Miscellaneous
1

Hello!

In short I’m looking at buying the ARM mbed NXP LPC1768 Development Board.

In the specs it says 6 pwm outputs. Does this mean I control up to 6 DC motors or servos with this (with additional h-bridges for dc motors)? Do I need to access hardware timers with this board to generate the pwm and if so, how many timers does the mcu have broken out to generate pwm signals?

I need a controller that can control at least 5 dc motors (will purchase h-bridges seperately) so I’m trying to see if this board is a good match.

I also like two UARTs because i plan on using one of them for wireless comms. having a spare one will probably come in handy in the future.

Sorry if I have posted this question in the wrong topic or thread.

Cheers,

Jay

2

Hi Jay,

When using mbed’s library functions, the frequency of all six PWM outputs must be the same, but you can independently vary the duty cycle of each output, so you can use those signals as speed inputs to H-bridges or position inputs for servos. You can find out more about mbed’s PwmOut functions here:

mbed.org/handbook/PwmOut

I’m sure that they rely on hardware timers, but the mbed libraries give you a higher-level interface so you don’t have to worry about working with the timers directly.

- Ben

3

That’s great, thanks Ben. You’re a legend!