How many Bump Switches allowed on a single robot?

How many red Bump Switches are allowed for autonomous mode?

12… as many digital ports as there are on the cortex. Generally speaking, Toss Up is only limited by the number of ports on the microcontroller

How positive about this are you?

The only limits on the amount of sensors or buttons one can put on their robot are however many ports one has available on their microcontroller, in this case, 12.

From a game rule perspective there is no limit to the number of VEX sensors allowed. HOWEVER, there is a limit to how many sensors the Cortex can use.

If you have no other sensors it is more than possible to have up to 12 bump or limit switches. These sensors are digital (IE, they’re either ON or OFF, 1 or 0, TRUE or FALSE) so they use the digital I/O ports. The reason you can only have up to 12 is because the Vex Cortex microcontroller only has 12 digital I/O.

It should be noted that other devices like the solenoids, quadrature encoders, LEDs, and jumpers also require digital I/O in order to use, so you have to budget the ports appropriately.

Other types of sensors will consume the analog I/O ports, sensors like the gyro, accelerometer and potentiometer.

The IME’s are special, they daisy-chain. That is one plugged into another plugged into another. The chain only uses the single I2C port and can support about 10 devices according to PROS.

The Cortex also has two UART ports which currently can only be used with the Vex LCD via the serial y-cable.

So to recap…

12 Digital I/O for:

  • Bump switches
  • Limit switches
  • Quadrature encoders (2x ports needed per)
  • Solenoids
  • Jumpers
  • LEDs

8 Analog I/O for:

  • Gyros
  • Accelerometers (3x ports needed per (if you want all three axes that is))
  • Potentiometers

I2C for:

  • IME’s

UART for:

  • LCD

… and as mentioned already, it’s up to you to budget them appropriately. If you want to use 12 limit switches you can, but don’t expect to use quadrature encoders as well.

Hope that helps. -Cody

You could actually have 20, 12 on digital ports, 8 on the analog ports :slight_smile:

Couldn’t you technically use Y-Cables to add even more?

Technically, but not for competing in Toss Up.


I saw at a recent competition something that was a bit different. One team had about 8 bumper switches, all beside each other, to select their autonomous routines. If they have the ports, I mean, why not, but it did look a bit funny.

Among some of the old stuff our school had, I found one robot with an arm, of which the whole weight of it rested on two bumpers, pressing each other, not even plugged in. Using sensors for structural features, yay!

Kind of tempted…

Unless someone would care to quote a rule saying otherwise, the limit on bump switches allowed on a robot is approximately 10,000.

That’s a ballpark estimate of the number of switches that could be packed into an 18"x18"x18" cube.

9,990 of them might not be particularly useful, but they would be legal. :rolleyes:


I was about 90% sure but I didn’t want to go off saying it could be done without knowing for sure.

Can the solenoid driver and LEDs be used on analog ports as well?

I think you can have way more…:smiley:

(This was cody’ s cortex)

For autonomous selecting I think a potentiometer will do, as long as you have a lcd display to aid you. And for triggering I like limit switches because they save space. Bumpers just look cool.

Or a Vex Speaker to verbally tell you which auton is chosen. No more squinting to see the LCD. No more having to tell your teammates which buttons do what. It’s effortless.

Don’t forgot about it’s bigger brother…

Think that’s 200 limit switches. Disclaimer, Photoshopped Cortexes may seem like they have more ports than actual Cortexes. Now that I look at this I feel like I should have added a few extra battery connectors to power all that crap. Actually a Cortex with two battery connectors would be pretty snazzy, always felt like the Power Expander was kind of a bad patch why not make it one device? We’ll add that to the Cortex 2.0 suggestion list.

Some motor ports couldn’t hurt either, maybe 40-50 would do.

Does that one support VEXnet 4.0???

12 digital ports + unlimted decoration bumpers

Just curious, how would one program the touch sensors on the analog ports? What would they be configured as in RobotC’s Motors and Sensors setup? I’m guessing that a SensorValue] of such a sensor would return either a low value or a high value, and it would be up to the programmer to set a threshold and convert that to 1 or 0 within the program?


You could have more than 20 by having Y cables. I am not sure if these would work as AND’s or OR’s but you could then have many sensors on just 1 port.