Today, we're going to compare the original Raspberry Pi Pico with the newer Raspberry Pi Pico W, now with a wireless interface. Take a look at the similarities and, most importantly, the important differences. Let's get started!

Let's start off with a side-by-side. Here, I have the Pico (the original Raspberry Pi Pico) and this is the Pico W. The major and obvious difference is, of course, the Pico W is dominated by this wireless interface circuitry. This is the Infineon wireless interface and this part of the circuit board is the antenna that's backed right into the circuit board. So, that means when you mount this in an enclosure, make sure that you don't have any metal nearby this part of the Raspberry Pi Pico W. Keep this away for best performance of the wireless circuitry.

Because the antenna is populating this bottom edge of the board, it looks like they've moved the three-pin debug header to right in the middle of the circuit board here. And that makes a lot of sense. I don't know how many of you are using the debug header, but I'm sure it's only a few power users that are really making use of that, so I don't think that's a big deal.

And so, all these extra goodies have pushed the RP2040 a little higher on the Pico W compared to the Pico. We still have USB micro B for power, just like the original Pico. It looks like the power circuitry is a little bit different, so we'll take a look at that. Here, we can see a larger switch mode chip and a few more passives surrounding that switchman power supply. The boot select is in the same position and, even though the QSPI flash chip has moved, it's still two megabytes. Interesting to note, the top two mounting holes are the same on the two devices, but the Pico W has plated-through mounting holes and this is probably for integrity of the antenna.

If you put a metal fastener through these holes it will be connected to this plane, so just be aware of that. Looking at the back side, it looks like the pin outs on the 40 pin breakout are identical between models and so that should mean that you can transfer your designs or your code from one model to the other without having to change anything.

Nice! I mean, we've introduced a whole wireless circuitry so there's a whole bunch of technical jargon on the back, the FCC ID and all the technical certifications on the PicoW, whereas the original Pico is a little bit more minimal and clean.

That's no big deal if you've ever looked at the pin out for a Pico and seen that it jumps from GP22 to GP26. You might have wondered where those general purpose I/O went and now it kind of makes a bit more sense. On the PicoW, there are four internal GPIO that are not broken out to the breakout header. GPS 23, 24, 25 and 29 are all GPIO from the IP2040 that interface directly with the Infineon chip. They are not broken out onto the header and so this forms a SPI bus to communicate between the two chips.

And that brings us to our next major point of difference. While the pins on the breakout headers are the same for both these Picots, GP25 on the Pico was used to control the user LED, but now GP25 is being used to drive the wireless interface. So if you have a project that uses the user LED on the Pico and you want to port it to the PicoW, you'll have to change the pin definition and actually the new pin is the WLGPIO0 on the wireless interface. So we'll actually be driving this LED over SPI by driving this wireless interface to turn it on and off.

There's a couple other GPIO broken out on the Infineon wireless interface. GPIO1 is used to toggle the power save mode for the switch mode power supply and GPIO2 sensors.

Whether V Bus is high or not so it senses if we have USB power connected, I think it's time we looked at the schematic on the left. I have the Pico and on the right I have the Pico W and we're looking at the power input. Here's the USB port and the switch mode power supply and the same for the Pico W.

We can see the same thing again for GPIO23 on the Pico which handles power save mode for the switch mode power supply. Now we have GPIO1 being used for that purpose and here we can see the same thing for the user LED. The Pico uses GPIO25, another internal GPIO, but since that's being used for wireless now we're using one of the GPIO on that chip to drive the user LED. So I think of those differences really the onboard LED is the one that matters the most, the other two are a little bit esoteric but now you know.

Looking at the switch mode power supply, we can see the Pico uses an RT6150B and the Pico W uses an RT6154. So comparing those two data sheets with the one on the Pico on the left again and the Pico W on the right, they look like they're from the same family of devices. It looks like the power supply used on the Pico W has a pretty generous maximum load capability but we'll have to do some more investigating to see if that's actually realized in the way the circuit was designed.

Now since both these boards feature an RP2040 clocked at 133 megahertz and the same flash size, it should come as no surprise that they're basically identical as far as the microcontrollers are concerned. The real differences really just lay in the physical differences.

Thanks for joining me for this quick overview on the differences between the Pico and Pico W. The Pico W has an extra wireless interface and a few internal quirks. If you're excited to learn more, then check the resources at the bottom of the article. Until next time, happy making!