Hi,
I’m a beginner and I would like to control the 12V12 with an arduino uno. Can I Control it using the PWM as input but still acquire the feedback value using serial if I connect the Jrk’s TX to the Arduino’s RX ?
Thanks,
Orit
Hi Orit,
The jrk 12v12 uses a single pin (RX) to either receive RC pulses (PWM) or serial commands; you would not be able to simultaneously send RC pulses to the jrk and also send it the serial command for getting the position. We recommend you communicate with the jrk using the TTL serial interface. This way you could send accurate target position updates while receiving position feedback at the same time.
Josh
Thanks for the quick answer.
Since I have the RX already wired with one of my pwm pins on the Arduino due I want to give it a try with pwm control.
I read that the available pwm frequencies on the jrk are 5khz and 20khz. The Arduino due pwm frequency is 1khz, that means I need to find a way to change it to 5khz/20khz, right?
What pwm resolution I need to use and what is the range of the values I can give the pwm?
Thanks,
Orit
Hi again,
Another question,
I read the input section of the users guide and noticed that the " input interface accepts pulses from 400 to 2600 μs at a frequency between 10 and 150 Hz".
Can you please explain what is the 5k/20k?
Another one, I have the pin 13 on the due connected to the RX with a resistor of 100kohm connected to the ground, is this setup any good? Also the due is 3.3 v and I noticed the high needs to be between 2-5v, do I have a problem?
Thanks!
Orit
Hello.
It sounds like you are confused about the inputs accepted by the jrk controllers. As Josh mentioned, the jrk can accept standard hobby RC pulses; this is different from duty cycle-controlled PWM signals. When configured for RC input, the jrk accepts RC pulses with pulse widths from 400 to 2600 μs at a frequency between 10 and 150 Hz, as you mentioned. The output on the motor output pins is a duty cycle-controlled PWM at either 5kHz or 20kHz (depending on how it is configured in the “Motor” tab of the Jrk Configuration Utility).
As far as the 100k pull-down resistor you have connected to the RX pin, please note that the RX pin is pulled up to 5V already, so by adding a pull-down resistor you are essentially creating a voltage divider. If you are trying to use 3.3V logic signals, you should probably consider using a logic level shifter between the two devices to be safe. However, the jrk should recognize 3.3V as high, so as long as you are not connecting any 5V signals back to your Arduino Due (like the jrk’s TX pin), you might be fine without the level shifter.
Brandon
Thank you so much for your answer!