The Jetson has a mini PCIe slot, perfect for adding functionality like that provided by the Intel 7260, a 802.11 ac, dual band Wi-Fi plus Bluetooth adapter. I bought the device here: Intel Network 7260.HMWG WiFi Wireless-AC 7260 H/T Dual Band 2×2 AC+Bluetooth HMC, along with a couple of antennas. Note: After I filmed the video, I bought some screws from Amazon (3/16″ Length, #2-56 Threads) to hold down the 7260. Here’s the installation video:
In order to get wireless to work on the Jetson, you have to do some kernel changes and load the device drivers. In order to achieve that, I installed the Grinch LinuxForTegra kernel that was developed in the Jetson community. You can read more about that here.
In the video, you’ll see that I also installed an Edimax EW-7811Un 150M 11n Wi-Fi USB Adapter, also from Amazon. At $8.70 as of this writing, it seems like a no brainer.
Configuration and Testing
For the wireless network, I have an Apple Airport Time Capsule which is wired into a cable modem. The Airport is 802.11ac. While all the marketing people suggest that these devices always run close to the claimed maximum theoretical limit, for some reason it seems I get somewhat less throughput.
After flashing the Jetson with the Grinch kernel, I installed both the Intel and Edimax. I didn’t have any issues with the Intel, the Edimax seemed a little flaky. The Edimax would lock up, disconnect, and simply disappear from the USB device list. However, this is also the first time that I had USB 3.0 enabled on the Jetson connected to a 3.0 USB hub, so there could be some issues with the hub and/or the Edimax in that configuration.
One of the nice things about the Intel is that has external antennas, so that it’s possible to tune the device. While I used “real” antennas, a proper length of wire could be very effective as well as light and easy to mount in a chassis. That’s the method that most laptop and desktop machines use, as well as mobile robots. Plus the Intel has Bluetooth, while the Edimax does not.
So how do they perform? I used iperf for testing. I installed iperf
sudo apt-get install iperf
On both the Jetson and a MacBook Pro (2013).
I used the MacBook Pro as a server, and the Jetson as a client. I also swapped those roles that so that the MacBook Pro speed could be measured.
On the wired network here, which is one gigabit, both the Jetson and the MacBook pro ran about the same speed, around 900 Mbs.
The MacBook Pro on wireless averaged around 300 Mbs, with a low of 206 Mbs and a high of 357 Mbs over 10 runs.
The Jetson using the Intel 7260 averaged 63 Mbs with a low of 56 Mbs and a high of 75 Mbs over 10 runs.
The Jetson and the Edimax weren’t too happy together with iperf, it averaged around 5 Mbs when it ran at all. The strange part is that on the Ookla speedtest.net website, the Edimax ran 13 Mbs in the test. There may be several explanations, I just don’t know which fib to tell about it.
So the Jetson with the Intel is about third the speed as the MacBook, the Edimax at best about a third the speed of the Intel. Note that the Edimax is 802.11n which is about three times slower than 802.11ac.
These tests were run right after my first Grinch installation and the Intel installation. So no tuning, just plug it in and see what it does. My guess would be that there is room for improvement in those numbers with the proper network magic and sorcery. All in all, I think it’s a good value for $35 bucks with antennas. With the Edimax I’m sensing that it’s unhappy with the setup for some reason, probably with the USB hub where it’s installed. Still, for under $10 it’s hard to be too upset with it.