New product: A-Star 32U4 Prime LV

Posted by Paul on 12 December 2014

The A-Star 32U4 Prime LV is the newest member of our A-Star family of programmable microcontroller boards. This is the first Pololu board with the familiar Arduino shape: it shares the pinout of the Arduino Leonardo and should work with Leonardo-compatible shields. With some code changes, this A-Star can also serve as a substitute for the similar Arduino Uno in many projects. However, there is a lot more to it than Arduino compatibility!

Unlike the Uno and Leonardo, the A-Star Prime has an efficient 5 V switching regulator and a seamless USB power switching circuit. This “LV” model uses the same power circuit, based on the Texas Instruments TPS63061 and TPS2113A, as the A-Star 32U4 Mini LV. Like that board, the A-Star 32U4 Prime LV can operate from 2.7 V to 11.8 V and supply about 1 A at 5 V, safely and efficiently switching between USB and external power without the limitations of components like fuses or diodes. It also includes a power switch, multiple power input connection points, and optional battery voltage monitoring, making it convenient to use in a variety of power supply scenarios. Here is a diagram of power distribution on the board:

As you can see in the pictures, there are few extra rows of pins next to the normal Arduino headers. The point of these is to give you more connection options: we have included an extra access point (on a 0.1" grid) for most of the pins, as well as extra power and ground buses. The power buses are unconnected by default, so you could, for example, wire VIN directly to a bus and solder in servo connectors in one place (the LV regulator works great on a four- or five-cell NiMH pack), while having another bus run at 3.3 V to power an array of low-voltage sensors. As another example, these buses are a convenient place to add your own custom pull-up or pull-down resistors.

There is a lot of space available in this form factor compared to the typical Pololu breakout board, and we hate to waste space, so we packed it with extra, optional peripherals:

You might recognize some of the optional peripherals from our line of Orangutan Robot Controllers and the 3pi Robot. These are features that we have found really handy in our projects over the years: three user pushbuttons (sharing the MISO, RXLED, and TXLED lines), a buzzer for beeps and simple music (optionally controlled by digital pin 6), and a connector for an HD44780-based character LCD. You can enable just the features you want with jumpers; the ones you do not use will not interfere with shields or other electronics. On some models, we are also including a microSD card slot that works with the Arduino SD library, so you can easily turn your A-Star Prime into a datalogger or access large scripts and media files.

Here is what the A-Star 32U4 Prime LV looks like with all optional peripherals installed:

This configuration is available pre-assembled as Pololu item #3109, while a configuration including pretty much everything but the LCD is available as Pololu item #3108. (You can still install an LCD yourself later.) For other configuration options, please see the individual product pages below or the A-Star 32U4 Prime LV category page.


This is a very interesting board!

One thing I'm not sure if you obviated: to include female pins in the bottom side so we can use it directly attached to zumo robot.

Thank you for the compliment. The versions we sell preassembled with standard female Arduino headers can plug directly into the Zumo just like a Leonardo or Uno (i.e., upside down).

That's the problem, John. If you upside-down the board then the lcd is useless.

At least, you should provide an extended pinhead version instead of the normal version, so it should be possible to solder female pinheads in zumo robot and use them both together in its natural side (not upside-down).
What you are suggesting does not make sense, since the A* Prime's pins would not match the Zumo's right-side up. Also, some of the pins used for the LCD conflict with their use on the Zumo Shield.
You are right Jon, the zumo is designed only to have the Arduino (or like) upside-down, so there is no way to come across this. The LCD would requiere an adaptor or similar to be usable in that way. Pins confict with LCD and Zumo? That's a big problem then to what I was planning (use this board for zumos).
While the LCD pins on the A-Star Prime are remappable, it's probably not that practical to use it on the Zumo with an LCD. However, we are currently working on a Zumo version with built-in LCD support, so stay tuned!
do you have .step files for this board? I am tying to do a fit check and set up mounting for my enclosure. I can work with IGES, step,... etc.

Hello, Caleb.

We have put up step files for those boards under the "Resources" tab on the A-Star Prime's product page.

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