Self-driving cars are, apparently, the next big thing. This thought is predicated on advancements in machine vision and cheaper, better sensors. For the machine vision part of the equation, Nvidia, Intel, and Google are putting out some interesting bits of hardware. The sensors, though? We’re going to need LIDAR, better distance sensors, more capable CAN bus dongles, and the equipment to tie it all together.
This is the cheapest LIDAR we’ve ever seen. The RPLIDAR is a new product from Seeed Studios, and it’s an affordable LIDAR for everyone. $400 USD gets you one module, and bizarrely $358 USD gets you two modules. Don’t ask questions — this price point was unheard of a mere five years ago.
Basically, this LIDAR unit is a spinning module connected to a motor via a belt. A laser range finder is hidden in the spinny bits and connected to a UART and USB interface through a slip ring. Mount this LIDAR unit on a robot, apply power, and the spinny bit does its thing at about 400-500 RPM. The tata that comes out includes distance (in millimeters), bearing (in units of degrees), quality of the measurement, and a start flag once every time the head makes a revolution. If you’ve never converted polar to cartesian coordinates, this is a great place to start.
Although self-driving cars and selfie drones are the future, this part is probably unsuitable for any project with sufficient mass or velocity. The scanning range of this LIDAR is only about 6 meters and insufficient for retrofitting a Toyota Camry with artificial intelligence. That said, this is a cheap LIDAR that opens the door to a lot of experimentation ranging from small robots to recreating that one Radiohead video.
Although the BeagleBone Green was announced at the Bay Area Maker Faire last May, there hasn’t been much said about it on the usual forums and IRC channels. Now, it’s finally out and I got my hands on one of them. Through a cooperation between the BeagleBoard foundation and Seeed Studios, the best small Linux board for doing real work with small Linux boards is now cheaper, a little more modern, and green.
The BeagleBone Green is an update to the venerable BeagleBone Black, the dev board based on a TI ARM Cortex-A8. It’s an extremely capable machine with a few interesting features that make it the perfect device for embedded applications. With the BeagleBone Green, the BB Black gets a small hardware refresh and a drastic reduction in price. If you want to do real work on a Linux board, this is the one to get. Check out the review below for everything that’s been updated, everything that’s the same, and why this is one of the most interesting developments in small Linux boards in recent memory.
The Differences From The BeagleBone Black
The BeagleBone Black has been around for more than two years now, but it’s still an extremely capable machine. The BeagleBone Green borrows heavily from the Black, with a few changes to satisfy the cost-reduction goal, and to make the BB Green slightly more accessible.
By far the largest change is the removal of the microHDMI connector. This is accompanied by a large bare spot on the board where the NXP HDMI Framer chip once was on the BB Black. When I talked to [Jason Kridner] his justification for the removal of the HDMI capability of the Green was that ‘nobody used it.’ This is fair and true; if you want a media server, you get a Raspberry Pi, and if you want a tiny Linux box to toggle pins very quickly, you get a BeagleBone. The removal of HDMI plays to the BeagleBone’s strengths, and makes it a less expensive board. You can’t argue with that.
Also on the list of changes are the addition of two Grove connectors. These connectors are part of a modular system of electronics that put a UART or I2C bus on a single connector. With these connectors and a few modules from the Grove System, building simple projects is a snap. The addition of two Grove connectors – one UART, one I2C – is Seeed’s largest contribution to the BeagleBone Green, and with a large catalog of parts ranging from simple logic gates to OLED displays and GPS modules, it’s pretty handy.
Aside from those changes, the BeagleBone Green is pretty much exactly the same as the BeagleBone Black. It has the same amount of RAM, the same processor, the same amount of eMMC Flash, and the same pinout as the BB Black. The Green moves to a USB micro connector for the power and serial connection. This had been USB mini on the BeagleBone Black. That’s a welcome change that’s long overdue. The barrel jack for power has been removed from the BeagleBone Green, and the larger USB port has been moved right next to the Ethernet socket.
As is the case with the BeagleBone Black, the Green comes with the Cloud 9 IDE already installed on the Linux image on the eMMC. This is a cloud-based IDE, but is hosted on the BeagleBone. For a device that really isn’t meant to be a desktop computer, this is the easiest way to get code up and running on a tiny Linux box. Combine this with a serial terminal, and it’s really all you need.
Why It’s Great
Although the BeagleBone Black has been around for a while now, and the BeagleBoard even longer, the Beagles have been playing second fiddle to the Raspberry Pi forever. This is a shame. The Raspberry Pi is not the ideal tool if you want real-time control of a lot of pins, and the GPIO expansion on the Pi is more of a kludge than something it was designed for.
The removal of the HDMI port in the BeagleBone Green doesn’t make this board any less capable. Like I mentioned above, nobody used it anyway. Add to that the fact you can buy an LCD cape for the BBG – and have it work with the 3D accelerator – and you’re really not losing any capability, just shaving sixteen bucks off the price. The BBG will launch with a $39 price tag, or about the same price as a Raspberry Pi. While it won’t impress many people that want a cheap Linux box for retro video game emulation, it is a great board for anyone who wants to get real work done.