Using GPIO pins on Digital Sidecar

Okay . . . So, what we need to do is trigger a trunk latch through Lab View. We were thinking that using the GPIO pins on the digital side car might be the best way to do this, but we haven’t been able to figure out exactly how to do that.

(we've searched the forum, but haven't found answers that we could understand and/or make work)

This latch we're triggering also has a 'signal' line which is connected to a switch that engages when the latch is triggered that we wanted to send that to the dash board so the drive team could tell when the latch had engaged.


You’re going to need to know what voltage the signal on the latch needs to be, ie. +5vdc or +12vdc.
Next you will need to determine if the GPIO pins can provide it.
If the GPIO can not, then you may need to develop a driver that will take the output of the GPIO pins and covert it to the needed voltage/power the latch will need.

thank you very much for getting back to us!

we’ve been using 12v to test it. as it’s a car trunk latch we figured it would be the same twelve volts that most of the electrical system is. It may be possible to trigger it with 5v. (we’re testing now) In any case, we’ll get power to it, somehow.

The specifications from the manufacturer says that the signal line, the one we’d want to run to the dash board, is 5 volts.

I assume these are two separate things.
we’re trying to:
A. Trigger the latch
B. send a signal to the dashboard

The thing we’re having difficulty with is on the LabView end. How do we send a signal to the GPIO pins? How do we receive a signal from the GPIO pins? Are the Digital Sidecar GPIO pins the best way to be doing this?

Assuming the latch is a legal electric solenoid actuator per R29, it must be controlled by a Spike Relay or a Solenoid Breakout output per R51.

On the 5V receiving side, the DIO is the best way. The Digital Input example on 358’s page may help:

Thank you very much for that information. That is very informative. I believe that it’s legal under R29.
The information in R51 we were unaware of. We’ll change course on our triggering system to accommodate.
We’re taking a look at Team 358’s example now.

Thanks again. This is an amazing resource that we’re very grateful to have access to.

A trunk latch isn’t one of the legal motors, but it is possible that it satisfies the rules for electric solenoid actuators. R29 permits Electrical solenoid actuators, no greater than 1 in. stroke and rated electrical input power no greater than 10 watts (W) continuous duty at 12 volts (VDC)

Do you know whether what you’re using meets the limitations? Do you have a part number?

Thank you for replying. I believe we are indeed meeting those specifications, but have been attempting to double check to be sure.

It’s a 05 06 07 Suzuki Forenza Trunk Lid Latch actuator.

Measure the current when latched and unlatched. It must not exceed 10/12=833mA in either situation.

I’d be surprised if it meets that requirement.

We spoke to a number of people, including a robot inspector for our upcoming regional, and discovered that our trunk latch is indeed not legal.

However, the trunk latch does have a manual latch release (to prevent people from being locked in the trunk), so we asked if we could simply cut the wires and trigger it with a servo. Our inspector directed us to Q288 in the Q&A portion of the FIRST website which indicated that even if the motor was not powered it would still have to conform to the requirements of R29 and R51.

So we have removed the electrical actuation system completely and the latch is now purely mechanical. We intend to trigger it with a HiTech servo from AndyMark or pneumatically.

Thank you again, everyone, for you assistance in figuring this all out.