Friday, July 30, 2021
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Flowstone Workshop 15

Flowstone-HeaderFlowpaw – A Robot Exclusive

FLOWSTONE WORKSHOP 15-1The Physical Computing System

Welcome to the FlowStone Workshop number 15, where we give a beginner’s guide to computer programming using the FlowStone graphical programming language and FlowBotics Studio.

In this issue we are going to look at the new FlowPaw interface from DSPRobotics. This is the 2nd generation of Hardware from DSPRobotics. First there was the FlowBoard DAQ and now DSPRobotics have teamed up with MikroElektronika to bring out possibly the most versatile robotics/software development system ever: FlowPaw!


FlowPaw is a very powerful USB interface board shaped like a paw with four claws; each claw is a socket for one of over 20 Claw Click boards.

The FlowPaw board with four claws connected.

These range from simple relays and buzzers to LED displays, gyros, accelerometers,proximity sensors, etc. Also on the board are four push buttons, four colored LEDs, up to 16 digital ins, 16 digital outs, 4 x 12-bit analogue ins, and 8 x servos outs. More importantly the FlowPaw board works directly with FlowStone and FlowBotics Studio from RobotShop, making programming a joy. FlowPaw is an HID (Human Interface Device) USB device and therefore needs no additional drivers to be installed, as these are part of Windows.


The standard FlowPaw kit comes with the FlowPaw board, USB cable, example CD, and four Claws (Buzzer, 8×8 LED display, irProximity Sensor & 3 Axis Accelerometer) but this is just the beginning. There are over 20 Claws to choose from, here are just a few:

With over 20 claws to choose from, anything is possible.

All of the difficult low-level programming needed to interface with these boards is already done for you in the pre-programmed FlowPaw firmware. This makes them plug and play–literally!


One of the main purposes of the FlowPaw board was to add a physical computing element into education to help inspire students to take up STEM subjects (Science, Technology, Engineering & Mathematics). Students usually start with something like Scratch, which is great for younger kids, but this soon runs out of steam when you want to learn about computer science or program robotics. After Scratch, there is a big void before you reach text based programming like Ruby, Python or C++. With FlowStone, you can start where Scratch leaves off and continue to program graphically but in a much more structured and powerful way. Then you can start to use bits of text code inside FlowStone using the Ruby programming language. Ruby, for those of you that don’t know, it is one of the fastest growing modern programming languages used by millions of developers worldwide. It’s one of the easiest to learn and is very powerful; FlowStone has the full Ruby language build inside. In fact DSPRobotics won an international award in Japan for its Ruby integration in 2013. We are creating lots of educational example files to accompany FlowPaw so that teachers can just plug it in and get going.


Nowadays Lego isn’t as simple as Lego, what with gears, shafts, motors and various technical bits added over the years, but FlowPaw builds on the same principals– simple plug-in boards that just work and no additional programming to do to get going instantly (unlike Raspberry Pi where interfacing to GPIO, sensors, I2C, SPI is quite advanced). Behold the FlowPaw Module:

The FlowPaw module is the heart of any programming task with inputs on the left and outputs on the right. Send signals to the inputs and they come out on the FlowPaw board hardware instantly, change any input to the FlowPaw board hardware and it comes out of the FlowPaw module in FlowStone in real time before your very eyes, no compiling, it’s like a magical machine that runs all of the time. On the bottom right of the FlowPaw module are four Paw connections, use these to connect to the separate software Claw modules. Plug your Claw into the FlowPaw board and then connect it in FlowStone and it will just start working. Disconnect and reconfigure your system as often as you like for different tasks and you have an entirely new device. You can even use multiple FlowPaw boards in the same project using their unique IDs to identify them. Once you are happy with you Claw choice, you can then use FlowStone to create your program around the hardware, control robots, read sensors, display text, make sounds, etc.


Using the eight servo outputs, you can easily control lots of robots using FlowPaw and FlowStone. We even connected a full five-axis robot arm from LynxMotion to great effect. The great thing was that we had the Claws free to add sensors and control. For example, you can use the three-axis accelerometer to control the robot arm movement by rocking the FlowPaw board forwards and backwards, you could use the proximity sensor to detect collisions in front of the arm, or you could use two joystick Claws to gain full control of the arm a bit like a games controller.

The FlowPaw module inside FlowStone.
FlowPaw controlling a Lynxmotion robot arm.


While connecting via USB has its advantages, like self-powering and fast data transfer, we can also go wireless using the Bluetooth Claw. This is no ordinary Bluetooth connection, but a new-generation one with up to 100m range and data rates up to 115200kbs (not the usual 9600 baud). This means that with the addition of some batteries to power the board and servos, you can go completely wireless with little effect on the data rate. We are looking forward to building our first FlowPaw Rover over the coming weeks with IR sensors to help navigate around the room. The cool thing is that this will be a telemetry-based system with no decision-processing on the FlowPaw board with everything happening back at base on the PC so we can tweak our program in FlowStone even while it’s running, dramatically speeding up development.


So as you have seen, there are lots of cool applications for the FlowPaw board in education and robotics, but remember, we have all of the power of FlowStone and the PC to develop really elaborate systems, we can use video and webcams to do image processing , control home automation systems, control real-time music synthesizers, create and play computer games, play MP3 audio, speech recognition, control disco lights via DMX, or building automation, data logging, send and receive SMS cell phone messages, GPS mapping, anything you can imagine!


The FlowPaw system offers a great out of the box experience and marks a step change in the way students, teachers, makers, and roboteers can create creative physical computing systems quickly and easily. FlowPaw is planned to be launched in September, starting from around $125USD for a complete system with a paw, 4 x claws, example files CD, software and manual.