arduino uno smd not recognized by IDE on mac

Using macOS with arduino 1.85 i can easily connect and upload sketches to an arduino Uno with the real chip. The IDE obtains proper board info
BN: Arduino/Genuino Uno
VID: 2341
PID: 0043
SN: 55732323330351514291

and connects on /dev/cu.usbmodem1421

I also recently obtained an arduino UNO R3 smd. Picture attached. When connecting the usb cable , the 'on' led is solid red and the L led is blinking. No board info is obtainable. Attempts to flash the arduino show an error saying nothing is connected.

How does one use this kind of arduino?

skypickle's picture


That board appears to use the CH340 USB-TTL serial adapter. You likely need to install the driver for that board:

After installing the driver, don't forget to select the correct port from the Tools > Port menu. Because of the CH340 chip, you will never get anything under Tools > Board info and the board will not be labeled as an Uno under the Tools > Port menu.

@pert
thank you. how does one identify these details from the terrible picture i posted?

Because there is clearly an SOIC-16 package there. The 16u2 on official boards (and the cp2102 on a few clones) are in qfn and ft232rl (used on some clones - but often counterfeit) is TSSOP-something (maybe 28?). They look very different from eachother

There are two different USB-TTL serial adapter chips commonly used on the Uno-ish boards: ATmega16U2 and CH340.

This is what the ATmega16U2 looks like:

This is what the CH340 looks like:

So even though I can't see the writing on the chip in your picture, just from the IC package I can make a good guess that it's CH340.