OpenALPR on a Raspberry Pi 4 and the Jetson Nano

brianegge said:
No, sorry. If I was I would post some stats. I am using the Jetson for computer vision. When it sees a vehicle in my driveway it sends the image to SightHound api. It then announces the arrival on my Alexa and opens the garage door if needed.
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I note that several cases are available for the Jetson Nano SBC. Is there a particular one that you use and can recommend?
 
wtimothyholman said:
several cases are available for the Jetson Nano SBC. Is there a particular one that you use and can recommend?
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I purchased one from Makeronics. I got a larger bundle, which was a waste, as I didn't need the WiFi M2 module and I used the camera for all of five minutes. This one is $17.90 and is what I would buy next time:
You'll need a 4A/5V power supply as well:
 
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I wanted to provide a preliminary report on my findings with the Jetson Nano SBC (version B01). I received the SBC and installed a Sandisk Extreme SD card with the Ubuntu image provided on the Nvidia web site. The Rekor Scout agent installed quickly and without a hitch. No special steps were required to install the CUDA drivers, as Rekor automatically incorporates them into the default installation for the Jetson Nano.

Right now the Jetson Nano is processing two 2 MP camera streams at nearly 60 FPS. I'm frankly a bit flabbergasted how well it is working. I will need to wait until tomorrow to test it against my current LPR setup with the same camera streams before I can provide an accurate determination of its performance, but right now it seems like a very workable solution for a low-cost LPR setup.

So what you'll need are the following: a Jetson Nano SBC (about $85), a 64 GB SD card (~$15), an enclosure with a fan (~$20), and a 5V, 4A DC power adapter (~$10). That's just $130 for a compact LPR processing unit that you can hold in one hand. The OpenALPR agent starts running within one minute of powering on and operates flawlessly in headless mode.

I'll provide additional data after I make some comprehensive daytime tests with more traffic. I also plan to configure the RPi 4 and test it as well, just to compare it to the Nano.
 
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So how do you know what is happening if it is headless? How do you control it? RLOGIN from a Win10 box?
 
Yeah I'm wondering if it can run the Watchman agent.
samplenhold said:
So how do you know what is happening if it is headless? How do you control it? RLOGIN from a Win10 box?
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SSH is how you remotely connect and administrator Linux boxes also.
 
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How hot does the unit run? Do you know if you can install Docker on the special Ubuntu image?
 
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biggen said:
How hot does the unit run? Do you know if you can install Docker on the special Ubuntu image?
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There's a fan built into the enclosure for cooling, and according to what I've read it should be sufficient to keep the GPU within maximum temperature limits at full power. I'll do some actual monitoring of the temperature later on.

As for Docker, I don't think there's any reason why you couldn't install it, but keep in mind that the CPU on the Jetson Nano SBC is nothing special. The reason why the Scout agent runs so well is because of the 128 core GPU.
 
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Some more data from additional testing today: in daytime, with significant motion in each image, the Jetson Nano maxes out at approximately 40 FPS while processing two 2 MP video streams from a couple of Dahua IPC-HFW5231E-Z12E cameras. It is possible the Jetson Nano could do better than this, but I'm getting under-voltage throttling warnings despite having a 5 V / 4 A power supply connected. Apparently this is a common issue with cheap wall-wart style supplies, due to the I*R drop through the power cables at higher supply currents.

Maximum CPU temperature is approximately 56 degrees C, and 54 degrees C for the GPU. The fan runs continuously but is very quiet. The quad-core CPU usage typically hovers between 25% and 50% while the agent is operating.

I have to say that I'm impressed. I assume that the Jetson is being used in Rekor's own Edge cameras, so they've clearly gone to some additional effort to optimize its performance.
 
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Some more information: Rekor just updated their documentation for Rekor Scout. Some relevant points:

(1) Docker can be used with the Jetson Nano, and in fact is recommended for various versions of Jetpack when installing the Scout agent. I chose the native driver install for the sake of convenience.

(2) Rekor now includes a section on the Raspberry Pi in its documentation, which says that even the latest versions of the RPi can only handle single-digit frame rates with the Rekor agent. So that answers my question that led to this original thread. That doesn't mean that the agent is useless on an RPi, but you'd clearly require a situation where a vehicle pauses (perhaps in front of a parking gate) long enough for the RPi to process the plate.
 
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Yeah I think the Jetson is a no brainer vs a Rpi. Runs cool and handles full frame rate. That’s good to know. Can you use a SSD with the Jetson units or only SD cards?
 
biggen said:
Yeah I think the Jetson is a no brainer vs a Rpi. Runs cool and handles full frame rate. That’s good to know. Can you use a SSD with the Jetson units or only SD cards?
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There's no provision for connecting an SSD, unless you put it in a USB enclosure. Fortunately high capacity microSD cards are pretty cheap nowadays. I would assume there's some way to boot via USB, but again ... microSD cards are cheap.
 
wtimothyholman said:
There's no provision for connecting an SSD, unless you put it in a USB enclosure. Fortunately high capacity microSD cards are pretty cheap nowadays. I would assume there's some way to boot via USB, but again ... microSD cards are cheap.
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Yeah its more about speediness and longevity for me with a SSD vs a SD card. I just prefer and use them when I can.

Ill look into seeing if it can boot via the USB.
 
biggen said:
if it can boot via the USB.
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Yes, you can.

robroyce.dev

How to Boot Jetson Nano From USB 3.0 (Natively) with Jetpack 4.5

If you have a Jetson Nano booting from a microSD card, you stand to gain both increased speed and a longer lifespan by switching out the microSD card for a USB 3.0 drive. In this guide, I’ll …
robroyce.dev robroyce.dev

I prefer to keep the OS and jet pack on the SD and my data and apps on usb storage.

To the other question regarding GUI, best is if you get comfortable using SSH to the host. You can setup vnc on the Jetson or even configure it as an X-client. Annoyingly, the jet pack comes with a full desktop. If being used headless you can save some memory by changing your default boot level.
 
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brianegge said:
Annoyingly, the jet pack comes with a full desktop. If being used headless you can save some memory by changing your default boot level.
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"Annoying" is relative to the user. For my part, I appreciated having the Nano boot into a full desktop. :)

In researching the Jetson Nano ecosystem, what I've found particularly interesting are products such as this: AI@Edge Fanless Embedded Box PC with NVIDIA Jetson Nano, PD Port

There's considerable appeal is having a low power embedded box that can run LPR software in a Linux environment at a respectable FPS, and can be configured for remote access and maintenance. It is a solution that could potentially enable LPR system deployment among the less-than-tech-savvy population.

So once again, thanks for pointing me to the Jetson Nano SBC. Experimenting with it has been an eye opener for me.
 
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