Serial communication between arduino due+ uno?

Hello :)

If I hook up rx of an uno to tx of a due and vice versa, will it work? If no, what other way is there that will?


Warning: Unlike other Arduino boards, the Arduino Due board runs at 3.3V. The maximum voltage that the I/O pins can tolerate is 3.3V. Providing higher voltages, like 5V to an I/O pin could damage the board.

Used to receive (RX) and transmit (TX) TTL serial data (with 3.3 V level). Pins 0 and 1 are connected to the corresponding pins of the ATmega16U2 USB-to-TTL Serial chip.

What does this tell you ? (you need a level translator circuit)

Well I knew that it runs on 3.3V, but not that this also included rx and tx :(

How can I build a translator circuit. Can you buy them?

An Idea I had was that maybe you could connect the USB ports of both of them (as they both run on 5V), but would that work?

Logic level converters

Unless you have a true bi-directional port transfer with another device, it makes more sense to use uni-directional level converters like the 74LVC245 or the 74HC4050. The Tx & Rx are one direction. They don’t change. Read the datasheets. The chips are 5V tolerant chips but the power supply pin determines the output voltage. For OUTGOING signals from the DUE, use the chip with a 5V supply. For INCOMING to the
DUE, use a 3.3V power to the chip. Obviously this means you need TWO chips. The TXB0108 is bidirectional
and therefore has TWO power inputs (one for 3.3V side, one for 5V side. If you have one of those, you can
mix OUTGOING & INCOMING on the same chip. For a little more money, you can save real estate on your
breadboard. I use both depending on the application and space available. I’ve never used the TXB0108 for
true bi-directional port transfers (SPI pins are unidirectional but I2C is BIDIRECTIONAL and would require
something like this.

We do have some other handy level shifters in the shop, from the DIP 74LVC245 to the fancy bi-directional TXB0108

However, neither of these are happy to work with I2C, which uses a funky pull-up system to transfer data back and forth. This level shifter board combines the ease-of-use of the bi-directional TXB0108 with an I2C-compatible FET design following NXP’s app note.

This breakout has 4 BSS138 FETs with 10K pullups. It works down to 1.8V on the low side, and up to 10V on the high side. The 10K’s do make the interface a little more sluggish than using a TXB0108 or 74LVC245 so we suggest checking those out if you need high-speed transfer.

While we designed it for use with I2C, this works great for SPI, TTL Serial, and any other digital interface both uni-directional and bidirectional. Comes with a fully assembled, and tested PCB with 4 full bidirectional converter lines as well as 2 pieces of 6-pin header you can solder on to plug into a breadboard or perfboard.