A-Star and Orangutan library

I have been building robots using the various Orangutan controllers for a couple of years. Many tasks are made easier by using the Orangutan library for encoders, motor control, using reflectance sensor arrays and much more. I want to try the A-Star Mini for a project which requires 20 digital i/o ports, my question is can I still use the Orangutan library routines somehow?


Some of the Orangutan libraries might work with the A-Star with modification. Libraries that rely on pins that are only found on ATmega328 will probably be trickier to modify. Also, libraries that rely on precise timing might be difficult to port since the Orangutan controllers use a 20MHz resonator and the A-Star uses a 16MHz resonator.

Since the A-Star uses the same ATmega32U4 found in the Arduino Leonardo , it might be easier to find and use Arduino libraries with the similar functionality.

- Jeremy

Thanks Jeremy.

Since there is a large installed base of orangutan users who rely on the Pololu libraries, and presumably the A-Star controllers are aimed at this user base as well as new users, are there any plans for Pololu to port the libraries for use with the A-Star? I’m sure I can’t be the only user who would welcome this!


Hello, Chris.

We do not have any current plans for something like that, but it’s good to get that feedback that you would want it. For the reasons that Jeremy’s stated, the Orangutan controllers could not easily be used with the Arduino Libraries, so we made our own libraries for them. Is there something specific in the Orangutan library that you like more than what you can get through existing Arduino libraries?

- Grant

I have started to use the A-Star because of it being like the arduino that I have used for a lot of projects. The newest one is Wall-e with the 8835 motor driver with Pololu motors and 5 servos through the micro maestro and a future voice recognition add on, I’m looking to use the A-Star in place of the large arduino boards. :bulb: Love your parts that can be used with established software and not just set for your brand…

Hi Grant,

Sorry for the delayed reply. The library functions I would need the most, and the most difficult for me to port for myself, are:

  1. Line follower sensor array functions
  2. Encoder functions
  3. PWM motor control

I have only used Orangutan controllers so far so I don’t know if I could find suitable Arduino libraries. Where should I look for A-Star compatible libraries?

I have to own up to being spoiled by the Pololu libraries. You guys have made it so easy for me to build competitive line following robots with a really short learning curve. Earlier this year I won a UK Robot Triathlon event organised by the Institute of Engineering Technology with my first ever self-built robot, based on a Baby Orangutan controller and a motor / gear train supplied by the organisers. See theiet.org/events/local/193512.cfm

Since then I have had other successes in UK competitions with Orangutan-based robots, but I want to incorporate motor encoders in my next line follower and this is beyond the i/o capability of my favourite Baby Orangutan. I am experimenting with the SVP-1284 and this is great for development with its large LCD, but it’s way too big and heavy for the final version.

I presented a paper at the annual UK Minos robotics conference in March this year where I described in detail how much Pololu had contributed to my successes. See this link: micromouseonline.com/2014/05 … 14-report/
and also the link in this report to my presentation slides.

Sorry to ramble on, but I think you wanted to know where I’m coming from!


Hello, Chris.

We do have an Arduino library for our QTR sensor arrays that should work with the A-Star. You can read more about the library in our documentation for it and download the library from its github page. For reading encoders, you might try using Arduino’s Rotary Encoder library.

We are glad you were able to have success with our Orangutan line and hope that the A-Stars will also work well for you.

- Grant

That’s great Grant, many thanks!


This is a follow-up for anybody else contemplating the move from Orangutan to A-Star. The bottom line is - Go For It!

Jeremy and Grant were right, it isn’t difficult to find the Arduino libraries required to duplicate the functions I used in the Pololu Orangutan library. The ones I am using are:

  1. Arduino encoder library: pjrc.com/teensy/td_libs_Encoder.html
  2. Arduino Library for the Pololu QTR Reflectance Sensors: pololu.com/docs/0J19
  3. AStar32U4Prime library: pololu.github.io/a-star-32u4-prime/

The last one has many useful functions which can be used without requiring the A-Star Prime board.

The main benefit in upgrading for me is the greater number of i/o ports available from the 32U4 processor against the older ATMega 328. I am also finding the serial monitor in the Arduino IDE very useful for debugging, although I guess I could have programmed this in my previous IDE (Geany).

My current project uses the A-Star 32U4 Mini LV with the DRV8833 Dual Motor Driver Carrier, driving 2 x 10:1 High Power Micro Metal Gearmotors fitted with the new magnetic encoders. The robot will compete in UK line follower and time trial events.