The RS485 interface is coming along smartly.... should have something before the end of the week (nice simple solution)

I have 4 potential devices that require 10-25 kHz input PWM simultaneously. Is the mbed capable of handling this?

Gary

Hi Gary,

The RS485 interface is coming along smartly.... should have something before the end of the week (nice simple solution)

Sounds good! I ordered some RS485 transceivers from Maxim, so would be interested in trying to recreate any RS485 stuff that you manage to get working (I assume you went with the Maxim parts after all?)   

I have 4 potential devices that require 10-25 kHz input PWM simultaneously.Is the mbed capable of handling this?

If i understand the question right, I'm afraid the answer is no. The six channels of PWM all share the same circuit to generate the period.It can happily drive accurate PWM at 40kHz, but all six channels then have to be 40kHz. I also have a few applications where I'd want each channel to have it's own period generator, so it is ashame.

Thanks,

Chris

Too bad about the PWM. I would need to have seperate generators for each of the four channels. Sigh.... I guess its back to analog control...     

Too bad about the PWM. I would need to have seperate generators for each of the four channels. Sigh.... I guess its back to analog control...

Yeah, it is a bit annoying :) Can you fill me in a little on the exact requirements for this application (and what it is!). What is the granularity needed? Rate of update? Just wondering if a s/w solution might work?

Cheers,

Simon

Our application involves controlling 4 underwater thrusters (brushless DC motors with dedicated controllers. The control involves a PWM signal ranging from 10 to 25 kHz and a single control line for motor direction. 

We update our sensors at 20 Hz and the thrusters are adjusted in the range of 5-10 Hz. Since each thruster is separate we would require a PWM for each. Instead we are going with our original +/- 10VDC control signal (interfaced maxim chip on the I2C bus. We could do without this part and the associated level shifting circuit with the PWM but alas.....

hi all my project is the following i have 8 thermisor like a ring ad i would make a project that detect the direction of the wind and my question is : can i use the PWM for my thermistors ?