Lately, I’m quite involved in developing a robot platform capable of navigating autonomously and do tasks in an orchard. The robot will work in the summer at high temperatures and the cooling system for electronics may not keep the temperature at an acceptable value. So I’m trying to reduce the working temperature in the box of the electronic components. The first on the list is the Raspberry Pi 3.
I use the Raspberry Pi 3 to run ROS Kinetic and control the robot. Since the robot will run continuously (24/7), I need a computer suitable for 100% up-time without unnecessary restarts or downtimes.
One of the situations where the Raspberry Pi 3 board would stop running is when the temperature exceeds a certain value. One of the optimizations is to run only the basic applications and the ROS nodes to control the robot. Running on Pi a small number of applications will consume fewer resources resulting in lower operating temperatures generated by the processing units. Even if I do my best to optimize the ROS nodes and the applications that run on Pi, I realize that I’ll need a more powerful alternative to Raspberry Pi 3 (B/B+) to complete the next steps in developing the robot.
The idea is to replace the Pi 3 with a more powerful computer at a decent price. A computer with a price of maximum €150. I did a little research to see the alternatives to Pi 3, and here is the result.
Jetson TK1 / TX1 / TX2 or Intel NUC is out of the question for now. Any of the three Jetson variants or the Intel computer cost a few hundred euros. It is worth investing money in such a board if running ROS along with a number of computer vision applications. Otherwise, I do not see any reason to spend hundreds of euro to run ROS nodes.
XU4 has a price of about €63, a Cortex-A15 processor that can provide 2Ghz and 2GB of LPDDR3. The only minus of this board is the lack of an integrated WIFi module. For €5 I can buy a WiFi module to provide a complete solution for wireless Internet connection. Otherwise, this board is the first on the list.
From Asus, we have a Tinker board that can run ROS Kinetic on a QuadCore ARM SOC 1.8GHz processor with 2GB of RAM. It has an on-board WiFi module and a price around €49. I have some doubts about the operating system. Some users from Amazon said that Android and Debian images provided by Asus were unstable and performed very poorly. This makes me think twice about making a decision. It is very important to me that the board will work without stopping for months. An unstable operating system can lead to a large number of reboots and downtime.
Rock64 is a less-known alternative to Pi 3. The board comes in several variants and the strongest has 4GB of RAM and an ARM Cortex A53 64-bit processor. The board has full support for Linux Ubuntu and Debian. The price is also good considering the performance – around €38. The only thing that worries me about this board is the community support. An active community saves me for a lot of hours to fix issues.