Makes Breadboarding Simpler!

Roberto Caruso

Issue 5, November 2017

Using breadboards with Arduino? Check this out! Panduino gives you the power of an UNO, with breadboard-connecting headers to securely hold it in place.

Securing more than a few connections between your Arduino and breadboard can create some challenges. So Roberto took a novel approach and designed his own solution! Accommodating an Atmega328p, it’s equivalent to an Arduino UNO with a few great changes.

Panduino is a great solution for breadboard connectivity. What inspired you to start development on it?

Thanks, I’m glad you like it. I realised that I spent a lot more time using the Arduino with a breadboard than with a shield, so saw the need for an Arduino-compatible development board to meet that need. The Nano was an option, but I found that sometimes it occupied more space on the breadboard than most of the devices I was interfacing to. Couple Nano with a breadboard power supply and voltage level converters, and you can see that a lot of the space occupied on the breadboard is really just overhead. External devices were also an option but that got messy and led to other problems. The Panduino aims to solves all of that.

The Panduino installed on a breadboard
The Panduino installed on a breadboard.

We’re certainly no strangers to breadboarding. How did you arrive at that name?

I decided to name it the “Panduino” by combining “pan” (short for “pane” which means “bread” in Italian) and “duino” relating the device to its lineage.

Makes great sense! Although it makes us think of Pandas too *nawww*. We noticed that the board has an open source symbol. Why did you decide to release it as an open source device?

The board was designed primarily with hobbyists and students in mind, and I felt that by releasing it as an open source device it could appeal to more of them. It would be great to see a school or a makerspace adopt it, not only as an assembly project but also use it as a springboard to get more people involved with programming and making things. All of the files are available on GitHub. I also felt that it was important to contribute back to the hobby, and this was one way to do that.

Is this pretty much the original board, or were there some major changes with the first revisions?

The board has not changed very much from the original design. The component layout was fine-tuned to make using it easier, and it was always designed for use on either the right hand or the left hand side of the breadboard. The one major design change that was required, related to the onboard voltage level converters; the initial design used just one MOSFET between the ATmega and the USB to TTL converter for each of the RX and TX lines. When the board was externally powered, the ATmega back-fed into the USB to TTL converter, so adding the second MOSFET to each line eliminated that problem.

Fantastic! What features does Panduino have, which an UNO board, for example, does not?

There are a few, including an on/off power switch and an onboard 3.3V regulator. A jumper allows you to use either 5V or 3.3V for VCC, which comes in handy when interfacing the ATmega to 3.3V devices. Because the microcontroller and the devices are at the same VCC, it eliminates the need for voltage level converters.

Handy! Does Panduino transfer power to the power rails of the breadboard, or is it still manually wired in?

It does not transfer power to the rails. The power headers are essentially used as anchors, and power is not transferred to any useable points on the breadboard. The main reason that it is not transferred to the rails, is because breadboards are not standardised. When I say this, I am referring specifically to the distance between the power rails. I have several of the older style North American-made breadboards that I like to use, which are different to those currently available from Asia. By anchoring into the points on either side of the center trough, the Panduino can be used with both styles.

That’s definitely a great point. It would be nice to connect power automatically, but we agree with the compatibility issues. Full headers are provided for the Atmega - any other handy breakouts?

Yes, in fact you can make use of both the 5V and 3.3V VCCs if you need to. When the VCC jumper is in the 3.3V position the 5V pin is exposed, which can easily be tapped with a jumper; and likewise for 3.3V when the jumper is in the 5V position.

A complete Panduino with Programming Adaptor
A complete Panduino with Programming Adaptor.

That’s handy! How is the Atmega programmed?

The board has a standard 6-pin ICSP header, which directly interfaces to a USBASP USBISP programmer with a 6-pin adapter.

That would allow you to save the USB programmer board for another project once you have programmed it! Are there any unusual parts required for the Panduino?

One of the goals was to design a low cost board by using readily available parts. Other than the PCB, all parts are available from several sources. It was also designed to make assembly as easy as possible. The board uses only one surface mount device (the 3.3V regulator), which is not difficult to solder.

Yes - as far as surface mount goes, a regulator is fairly straight forward, that’s great. What other features will we find on the Panduino board?

As mentioned earlier the board also has jumpers. One to select the source of power, external/USB, and another to select VCC, 5V or 3.3V. You’ll also find two standoffs on the far side of the board that were added to prevent it from accidentally rocking out of the breadboard.

If you had your time again to create the Panduino, would you change anything?

There’s really not too much that I’d do differently. Perhaps making it a bit smaller by locating the USB to TTL converter on the underside.

The board is already relatively compact, but it’s sometimes worth the experiment! What are you working on now?

Nothing at the moment, but I see the need for some low cost specialty programmers on the horizon!

Fantastic - we look forward to seeing what you create! Thanks again for taking us through Panduino!

Reading & Resources:

Roberto Caruso

Roberto Caruso

Industrial automation specialist and electronics hobby enthusiast.