I am trying to set up the Trex for Analog with serial override mode. For starters, I just want to get the motors to turn and I can’t get the motors to turn in Analog mode. I have been able to get it to work in serial mode.
I am using an Arduino Mega to set the analog values. I can’t get it past safe mode.
I tried just having the arduino digital 2 provide 5V to Channel 1 after letting it be at 0V for 10 seconds. That didn’t work.
I tried jumpering channel 2 through 5 to 0V.
Now, I am back to trying to set the calibration values through serial mode, so that I can get it work in Analog mode. What I don’t understand is what does the maximum byte set refer to. What tells the Trex that 5V is full speed? 127? 256?
Also, is there a way to send a reverse direction? Through the Arduino I can only output simulated analog through the PWM channels so I am not sure how I can set the Trex to ½ forward speed for example using PWM.
I apologize for the delayed reply. I have already responded to your email about this, but I will copy that reply here for others who might be following this thread:
In analog mode, the default calibration values result in a motor speed of zero when the channel voltage is Vcc/2 (2.5 V), full-speed forward when the voltage is Vcc (5 V), and full-speed reverse when the voltage is 0 V. However, it will not let the motors move until you satisfy the safe-start conditions by supplying voltages to all of the channels that correspond to approximately zero motor speed.
Why are you using an Arduino to generate your analog voltages? Without external circuitry, the Arduino can’t produce analog voltages other than 0 and 5 V, so it makes a very poor analog voltage control source; the two other control interfaces–RC or serial–are much more appropriate for use with an Arduino. If you are just trying to test the analog interface with your Arduino, I suggest you instead go directly to your actual analog voltage control source and use the TReX’s automatic calibration feature. I also suggest you send serial commands to set any channels you do not plan on using to be ignored.
