I am trying to download code onto my robot with Vex Coding Studio and my MacBook Pro, but the brain isn’t coming up as being recognized on VCS. I have Mojave 10.14.3, has anybody else had these issues?
The very first release of vexos had an issue connecting to OS X 10.14, as long as the V5 brain is on vexos 1.0.1 or later it should be fine. What age is the MacBook ? Does it have USB A ports or are you using a USB-C adapter ?
I’ve got a 2017 MacBook with 4 Thunderbolt 3 ports. I am using a usb-c to usb-a cable (the one that came with my Galaxy S9). One thing I noticed that was weird was when I plugged in the usb-a end in to a phone via an adapter, the MacBook started siphoning power from the phone instead of the other way around. Could this be the issue?
If (as I infer from your above post) you are connecting a USB-microB to USB-A adapter (AKA “USB OTG cable”) to the v5 brain, and then using a USB-A to USB-C cable to connect the OTG cable to your Mac, this will not work. The OTG cable is designed to allow a device with only a micro USB port (such as a phone or tablet) to act as a USB host, to connect devices like keyboards and flash drives. When downloading programs, the v5 brain is not the USB host (your mac is), and I doubt it has the necessary hardware/firmware to act in this capacity anyway.
You should instead be using a USB-C to USB-microB cable, or else a dongle like this one which will turn one of your USB-C ports into a USB-A port, and then you can use the cable that came with your v5 brain, or any normal microUSB cable.
I have seen dozens of teams use a USBC to A adapter and then a microusb adapter. As long as there isn’t a performance bottleneck in one of the adapters this should be fine.
A standard C-to-A adapter works fine. OTG cables that Android phones come with are not standard adapters from a master/slave negotiation standpoint, though. Per @holbrook, a device connected via an OTG cable can act as the master or the slave, and they can even swap roles on the fly.
If the devices connected can’t handle the protocol (i.e. the V5 Brain) things get weird.