Answered: I/O Ports

[MarkO]

ctx32

                 https://vexforum.com/images/statusicon/user_offline.gif                                                            
                             Junior Member

Join Date: Apr 2006
Posts: 9

                                                                                                                            http://www.vexlabs.com/vexforum/images/icons/icon14.gif                 **I/O Ports**             
                                                          How much voltage can the ports handle?

I want to run a remote relay to the Vex micro.
The relay will act as a signal for the micro to perform a certain task.
The relay is 12v. So I know it will have to be reduced down to what the
micro can handle.
Any ideas.
Thanks
Calvin Ricky Torrance https://vexforum.com/images/statusicon/user_offline.gif
Vex Robotics Engineer
Join Date: Oct 2005
Posts: 332

Re: I/O Ports
The Specifications for the Vex Controller are at http://www.vexlabs.com/vex-robotics-design-system.shtml. You will need a relay coil that can operate from the Vex Controller output voltage/current. You may need a smaller relay that will in turn trigger your 12V relay.

I just have to bring this up, because it has been bothering me for a while…

The web page Vex Robotics Design System shows the following under Inputs and Outputs:

Battery Input      7.2 volts nominal, 6 to 9 volts min/max input range

Interrupt Inputs     6

Digital I/O     16 max with no Analog, Each can be Input or Output     (shared with Analog)
Input Impendence

Analog/Digital - The input consists of a 470K pull-up to +5V and a series resistance of 1K to the uP.

Interrupts - The input consists of a series resistance of 1K to the uP. More info - Input Schematic.

Analog Inputs     16 max with no Digital, 10-bit resolution                        (shared with Digital)

    Digital/Analog as Inputs     
3 dB bandwidth of 150 kHz, weak pull-up of 470k-ohms to 5.0 volts,
need 0.0 to 0.6 volts for a low and 4.0 to 5.0 volts for a high

    Interrupts as Inputs
3 dB bandwidth of 150 kHz, weak pull-up of 47k-ohms to 5.0 volts,
need 0.0 to 0.6 volts for a low and 4.0 to 5.0 volts for a high

    Digital/Analog Interrupts as Outputs
As outputs these ports can drive an open circuit to 0.6v or lower for a low and 4.0 volts or higher for a high.
They can drive a 1 mA load to 1.6v or lower for a low and 3.0 volts or higher for a high.

    PWM Outputs
As outputs these ports can drive an open circuit to 0.6v or lower for a low and 4.0 volts or higher for a high.
They can drive a 1 mA load to 1.0v or lower for a low and 3.6 volts or higher for a high.

The Digital/Analog Interrupts as Outputs and PWM Outputs don’t make much sense to me as far as telling me what the Maximum Output they can drive. The really Interrupts, or is this just an editing error???Current DrawPWM OutputsinferDigital/Analog Interrupts as OutputsdrivereallyDigital/Analog Interrupts as Outputs

[Ricky_Torrance]

**The Current Draw on the Motor page is for the (+) Power Pin. The Digital/Analog Port, or Interrupt Port is referring to the Control Signal Line not the Power Line.

The Digital/Analog Port pins or the Interrupt Ports pins can be configured as Outputs.**

[MarkO]

@Ricky Torrance

**The Current Draw on the Motor page is for the (+) Power Pin. The Digital/Analog Port, or Interrupt Port is referring to the Control Signal Line not the Power Line. **

Yes, I forgot, PWM has both power and control…

The Digital/Analog Port pins or the Interrupt Ports pins can be configured as Outputs.

OK… EasyC 1.x does not let you change the Interrupt Ports to Output… But that is a cool feature…