There’s hardly a day that passes without an Arduino project that spurs the usual salvo of comments. Half the commenters will complain that the project didn’t need an Arduino. The other half will insist that the project would be better served with a much larger computer ranging from an ARM CPU to a Cray.
[Will Moore] has been interested in BEAM robotics — robots with analog hardware instead of microcontollers. His latest project is a sophisticated line follower. You’ve probably seen “bang-bang” line followers that just use a photocell to turn the robot one way or the other. [Will’s] uses a hardware PID (proportional integral derivative) controller. You can see a video of the result below.
It’s been a while since we’ve seen much action on the bristlebot front, which is too bad. So we’re happy to see [Extreme Electronics]’s take on the classic introductory “robot”: the Black Line Follower. The beauty of these things is their simplicity, so we’ll just point you to his build instructions and leave the rest to you.
The original bristlebot is a fantastic introduction to electronics, because it’s simple enough that you can cobble one together in no time. A battery, a pager motor, and a toothbrush head are all you need. But it goes where it wants, rather than where you want it to go.
Adding steering is as simple as tying two bristlebots together and firing one motor at a time to execute a turn. The Black Line Follower is of this style.
But that was more than five years ago now. What happened to the mighty engines of bristlebot creativity? Has the b-bot seen its finest hour? Or are we just waiting for the next generation to wiggle up to the plate?
The shoebox-sized robot exceeds [Bolt]’s top speed of 44-km/hour. At that speed, following a line gets tricky. It took the development team 8 prototypes to attain that capability. Inside the BeatBot an Arduino reads 9 infrared sensors for line detection at 100 samples a second. A digital servo controls the Ackerman steering mechanism to follow the line on the track or floor. Wheel encoders provide the data for speed and distance measurement.
The user can set the distance of the run and the time to beat. Run pacing can also be adjusted. LEDs on the robot provide the starting ‘gun’ and help the runner see the BeatBot using peripheral vision. Two GoPro cameras, front and rear, provide a visual record of the run.
Puma believes that actually running against a competitor, even a robot, improves performance more than just running against the clock. They’re betting a grown-up line follower will help Olympic class athletes improve their performance. Continue reading “Line Following Robot Trains Runners”→
There are quite a few flavors of line following robot. No matter how they’re made, most are built for speed and accuracy. The Cambot by [Jorge Fernandez] however makes use of a traditional video camera to read visual input instead of the reflective sensors we’re used to seeing in these types of robots. Because of this it lacks those swift and agile qualities, but scores points with its unique analog design, over-sized tricycle wheels, and stylish RCA jacks poking out on the side.
Coupled with a PIC 16F84A microcontroller, [Fernandez] divides the video input from the camera into 625 lines. The PIC is responsible for scanning horizontally across these lines and translating the proportions of black and white into PWM pulses. The duration these proportions are seen by the camera determines the PWM frequency fed to the left and right servo motors driving the robot.
As far as line-followers go, this is a refreshing retro approach to the concept. [Hernandez] outlines the finesse about driving his cambot on his blog (an English translation can be read here) and provides a complete schematic for those who are interested in whipping up their own quirky little machine.
Robots have always been a wonderful tool for learning electronics, but if you compare the robot kits from today against the robot kits from the 80s and early 90s, there’s a marked difference. There are fairly powerful microcontrollers in the new ones, and you program them in languages, and not straight machine code. Given this community’s propensity to say, ‘you could have just used a 555,’ this is obviously a problem.
[Carbon]’s entry for The Hackaday Prize is a great retro callback to the Heathkit HERO and robotic arms you can now find tucked away on a shelf in the electronics lab of every major educational institution. It’s a 65C02 single board computer, designed with robotics in mind.
The 6502 board is just what you would expect; a CPU, RAM, ROM, CPLD glue, and a serial port. The second board down on the stack is rather interesting – it’s a dual channel servo board made entirely out of discrete logic. The final board in the stack is an 8-channel ADC meant for a Pololu reflective sensor, making this 6502 in a Boe-bot chassis a proper line-following robot, coded in 6502 assembly.
[Carbon]’s video of his bot below.
The project featured in this post is an entry in The Hackaday Prize. Build something awesome and win a trip to space or hundreds of other prizes.
Back in the late 80s and early 90s, a lot of young electronics hobbyists cut their teeth with BEAM robots – small robots made with logic chips and recycled walkmans that tore a page from papers on neural nets and the AI renaissance of the 80s. Twenty years later, a second AI renaissance never happened because a generation of genius programmers decided the best use of their mental faculties was to sell ads on the Internet. We got the Arduino, though, and the tiny robot family is a more than sufficient spiritual successor to the digital life of the old BEAM bots.
The tiny robot family is [shlonkin]’s growing collection of small autonomous vehicles that perceive the world with sensors and act with different behaviors. They all contain an ATtiny85, a small battery, two motors, and at least one phototransistor and a LED. One robot has left and right eyes pointing down, and can act as a line follower. Another has a group of LEDs around its body, allowing it to signal other bots in all directions. The goal of the project is to create a whole series of these tiny robots capable of interacting with the environment and each other. Video of the line follower below.
You know you’ve got a good hardware platform if you can easily repurpose it with a code rewrite. And that’s what [Eric] continues to do with these little Hexbugs. This time around he’s bent the IR emitter and receiver downward to use as a reflectance sensor. This gives it the ability to follow a dark line on a light surface.
He originally patched an MSP430 into the $25 RC toy. The IR pair was intended for obstacle avoidance, which we saw in a recent links post. This hack does a great job of repurposing the avoidance system. Since the add-on hardware is mounted on a motorized turret, the single sensor pair can sweep back and forth to find the line it will follow. In one way this is better than most line followers which use multiple sensors mounted to the body. But the drawback is that this results in slower travel and won’t be winning any contests. Don’t miss the demo clip after the break.