As a small US-based electronics manufacturer, we have been contemplating tariffs a lot this year, especially over the last several weeks, when our mindset changed from primarily “let’s see what happens” to more of “this could be an existential threat and we need to act right away.” Like much of the world, we were shocked by the April 2 announcement of new, and high, US tariffs on seemingly everything from everywhere and the subsequent dramatic escalation of tariffs on China, which are up to 145%, or maybe 170% or 195% on some electronics components, as I write this on Saturday, April 12.

With the various pauses and extensions and exemptions that are announced almost daily, it might seem that the tariffs are just talk, but we have been getting hit by tariffs of 45-70% on electronics components for the past several months already. Often, these are for integrated circuits that we ordered months ago and that can ship from various countries, and we find out about the extra 70% cost only after we receive the parts. This summary from a recent Arrow Electronics order for some stepper motor driver ICs shows Arrow trying to get ahead of the tariff shocks and how high their estimate had gotten (I am not sure how they are calculating it, and it probably also changes day to day):

Order summary from an April 6 stepper motor driver chip order showing estimated tariff of 144%.

We just finally mostly recovered from the pandemic-era chip shortages, and we don’t want to wait too long on reacting as we did then, when some of our key stock was quickly bought up and left us unable to manufacture some products for nearly two years. So, over the past week, we have gone through and assessed the pricing of all of the thousands of products we sell. Since most products have various quantity price breaks and pricing for our distributors, we updated tens of thousands of prices.

Our system is not made for this. When we release products, it’s usually one at a time and we carefully assess our costs and competing products to set what we expect to be good prices. If there are small cost increases over time, we usually absorb them, and if there is a big jump in some component cost, we can reassess and reprice the affected products individually. But here, we are dealing with the sudden, not precisely-specified, and unequal cost change of almost every component. So, the price changes that we have made over the past week have been much less carefully considered and more dependent on formulas based on costs and countries of origin and other data we have available.

Many of the “individual assessments” amounted to looking at prices our programs spit out and seeing if they seemed reasonable, and in many cases we just flagged the item for further review later and accepted the proposed prices or overrode to stick with our old prices. And, in some cases, we had to override to make the prices higher still based on knowing that a particular part was already constrained or getting higher tariffs.

This morning (again, Saturday, April 12) as I started writing this post, I saw news reports that semiconductor devices would be exempted from the latest extra hikes. Even if that applies to the kinds of integrated circuits we use, I think that means the 70% portion that we have already been paying is still staying in place. It’s also not clear to me if things like inductors, which we’re currently paying an extra 45% on are going to stay at 45% or going to 170% or what (basically all commodity inductors in the world come from China as far as I know). Even if they do get some exemptions or the tariffs are walked back more broadly, I suspect the 45% increase will be a new minimum for a while.

These new exemptions announced today should be good news for us, but I find myself feeling deflated as I contemplate more and more effort having to go into constantly repricing everything while looking at bills for extra thousands of dollars in tariffs almost daily. (This post is mostly about the work going into pricing for our customers, but there is also lots of decision making about what to buy now, such as do we get extra material now before prices go up more, or do we hold out hoping for them to go down and risk running out of components? Will the demand still be there for a product if it’s more expensive? And so on.)

Anyway, the point of this post is not to whine or wallow or complain, but rather to give our customers and partners some idea of how we are dealing with the tariffs. Price increases are not pleasant, and we are working on keeping them to a minimum and reducing prices again when we can. We are also quickly developing a new price change notification feature on our website so that you can be notified of price changes on any products you care about:

New price change notification feature.

Because things are changing so quickly, we are rolling out this new website feature and I am announcing it before we have the notification email system implemented, so it might be a while before we can start sending out the notifications. I am thinking that until we have it all working and until things stabilize, this can also be a way for us to get feedback about which products might have been badly repriced and that we should prioritize for reassessment.

Please reach out and share your thoughts in the older established ways, too. Especially if you are a customer wondering about the future of some product, please let us know your concerns and we will do our best to give you whatever insight we might have and work with you on prices.

This is the fifth post in a series documenting the installation and first year of operation of Pololu’s 305 kW solar array. Here are the previous posts:

• Part 1: Background starting in late 2022 and how we committed to the $650,000 project by the beginning of January 2023, with a target completion date of May 31, 2023.
• Part 2: Installation from January 2023 through first day of operation on October 5, 2023.
• Part 3: System failures and production results during the first year of operation.
• Part 4: Analysis of electrical costs before and after our system was installed.

In this final post in the series, I will go over the costs and benefits of our solar system, some lessons learned, and my thoughts on whether this has all been worth it. Continued…

This is the fourth post in a series documenting the installation and first year of operation of Pololu’s 305 kW solar array. Here are the previous posts:

• Part 1: background starting in late 2022 and how we committed to the $650,000 project by the beginning of January 2023, with a target completion date of May 31, 2023.
• Part 2: installation from January 2023 through first day of operation on October 5, 2023.
• Part 3: System failures and production results during the first year of operation.

In this post, we will look at how our solar installation affected our electricity bills. Because operations were so dramatically altered by the pandemic starting in 2020, we have to go back to 2019 for the best baseline for electricity consumption and cost. To maximize the scientific rigor of our observations, we changed as many variables as possible since then, including: Continued…

We just released several small reverse voltage protection and ideal diode boards that can protect your projects from reverse voltage application. We have reverse-voltage protection built into many of our products, and we usually implement it using a P-channel MOSFET, like this:

Reverse-voltage protection using a P-channel MOSFET.

This approach is usually more efficient than just using a diode since the MOSFET has a lower voltage drop across it. However, P-channel MOSFETs have worse on-resistances than N-channel MOSFETs of similar prices and sizes. This has not mattered much for our lower-powered products, but that limitation is becoming more apparent as we are developing more products with maximum operating voltages over 40 V. The next common MOSFET voltage above 40 V is 60 V, and at that voltage and with currents above around 10 A, it starts becoming more size-efficient to use an N-channel MOSFET plus an extra chip to manage the additional complexities of controlling the N-channel MOSFET in this kind of application. This is how that circuit looks:

Schematic diagram of the Pololu Reverse Voltage Protectors.

Since we are planning on using this approach on several new products, we decided to make standalone product versions as well. Here are how the first products look, using 3×3 mm MOSFETs:

This lets us get up to about 10-12 amps continuous current and an operating range of 4-60 V, which is perfect for most of our products. We tried to make the board as small as possible, and for the input and output connections we are using a new slot approach that lets the boards work with standard 0.1" headers or connectors, 3.5 mm connectors, and 5 mm connectors.

Examples of various connectors that can be used with the Pololu 10A/12A Reverse Voltage Protectors (from left to right: 5mm terminal blocks, 3.5mm terminal blocks, 0.1″ headers).

Texas Instruments offers two similar parts for the MOSFET controller. The LM74500 offers the same functionality as the simple P-channel MOSFET, allowing current to flow in both directions as long as the polarity is correct. This is useful for applications such as motor drivers where we want power to be able to flow back from the motor into the battery. There is also the LM74700 version, which makes the circuit function as an ideal diode, allowing current to flow in only one direction. We are offering our boards with both controller options and with two MOSFET options, for a total of four product versions:

The datasheets for the LM74500-Q1 reverse voltage protection controller and LM74700-Q1 reverse voltage protection ideal diode controller provide additional information about adding a transient voltage suppressor (TVS) diode across the input as part of a more general input protection circuit. We have pads for an SMB-size TVS on the back side of the board for those interested in adding this kind of protection:

As with our other electronics products, we make these at our Las Vegas, Nevada headquarters, so we can build custom versions with that TVS populated with a part of your choice (typical minimum quantities to make that worthwhile are around 200 pieces).

Are these interesting products? Would you want to see higher-current versions with bigger MOSFETs? Let us know in the comments or on our X and Facebook posts.

Introductory special discount! Try some out for as low as $1.16 each using our introductory special coupon, RVPINTRO (limit 5 per version)!

Related products

	Pololu Ideal Diode Reverse Voltage Protector, 4-60V, 12A
	Pololu Ideal Diode Reverse Voltage Protector, 4-60V, 10A
	Pololu Reverse Voltage Protector, 4-60V, 12A
	Pololu Reverse Voltage Protector, 4-60V, 10A

Over the last two days, I attended the 2024 Western Regional Meeting of ECEDHA, the Electrical and Computer Engineering Department Heads Association. It was held this year at UNLV, which is only 3 miles (5 km) away from Pololu, in the engineering department’s new Advanced Engineering Building that was just opened earlier this year.

UNLV’s new Advanced Engineering Building, November 2024.

I was there representing Pololu as one of five local industry sponsors. The larger companies there were treating it more like a recruiting event, and while we have several UNLV alums working at Pololu along with half a dozen student interns from UNLV, I looked at the event more as an opportunity to meet some of our customers. I also got to see some of UNLV’s new facilities for engineering students and researchers. Continued…

This is the third post in a series detailing our experience over the past two years installing and operating a 305 kW array of 630 solar panels on our building in Las Vegas, Nevada. Here are the previous posts:

• Part 1: background starting in late 2022 and how we committed to the $650,000 project by the beginning of January 2023, with a target completion date of May 31, 2023.
• Part 2: installation from January 2023 through first day of operation on October 5, 2023.

I left off with our first look at the SolarEdge monitoring site on October 5, 2023. It’s nice to see nearly real-time generation results and status. The SolarEdge P1101 optimizers connect to pairs of solar panels, so that is the resolution we can see in the array. Here is a close-up as I write this at 10AM on October 31, 2024, with a section affected by the shadow from an air conditioner circled:

SolarEdge monitoring site solar panel array close-up at 10AM on October 31, 2024.

The 1.0.72 pair of panels and 1.0.19 pair of panels at around 130 Wh so far today have generated only about half as much as the nearby panels not affected by the shadows. Continued…

This is the second post in a series detailing our experience over the past two years installing and operating a 305 kW rooftop solar system on our building in Las Vegas, Nevada. In the first post, I covered some of the background starting in late 2022 and how we committed to the $650,000 project by the beginning of January 2023, with a target completion date of May 31, 2023. This post covers how the actual installation went. Continued…

October 2024 marked one year of operation of our 305 kW rooftop solar power generation system. In this series of posts, I will reflect on our installation and operation experience over the past two years to try to assess whether it was worth it. This first post covers some background leading up to the project and the overall system design. I will detail the installation process, the first full year of operation, and the production and financial results in subsequent posts. Continued…

We recently added six new low-power variants to our Motoron line of basic serial motor controllers: four Mxx550 1- and 2-channel versions, as well as 3-channel versions for Arduino (M3S550) and Raspberry Pi (M3H550).

1- and 2-channel micro motor drivers

The new M1T550, M1U550, M2T550, and M2U550 are single- and dual-channel serial motor controllers in a micro footprint. With a maximum motor supply voltage of 22 V, the Mxx550 versions are a great way to control small motors powered by power supplies up to 12 V and battery packs up to 12 cells in series for alkaline, NiCd, and NiMH, or up to 4 cells in series for LiPo. These are lower-voltage, pin-compatible versions of the Mxx256 models we released earlier this year, which have a maximum motor voltage of 48 V and can deliver slightly more current but are otherwise almost identical.

Here is the full array of tiny Motoron options, including I²C and UART serial interface versions:

Motoron motor controllers micro versions
	M1T550 M1U550	M2T550 M2U550	M1T256 M1U256	M2T256 M2U256
Control interface:	I²C or UART serial
Motor channels:	1 (single)	2 (dual)	1 (single)	2 (dual)
Minimum motor supply voltage:	1.8 V		4.5 V
Absolute max motor supply voltage:	22 V		48 V
Recommended max nominal battery voltage:	16 V		36 V
Max continuous current per channel:	1.8 A	1.6 A	2.2 A	1.8 A
Available versions with I²C:	headers soldered headers included	headers soldered headers included	headers soldered headers included	headers soldered headers included
Available verions with UART serial:	headers soldered headers included	headers soldered headers included	headers soldered headers included	headers soldered headers included
Price:	$12.49 – $14.49	$15.95 – $17.95	$16.95 – $18.95	$23.95 – $25.95

3-channel motor drivers for Arduino and Raspberry Pi

We also released larger (but still small!), 3-channel versions in Arduino (M3S550) and Raspberry Pi (M3H550) compatible form factors. These again have a maximum motor supply voltage of 22 V and correspond to the 48 V max M3S256 and M3H256 versions we released in 2022. Here is the full line of larger Motoron serial motor controllers, including the even higher-power, dual-channel Motorons in full-size Arduino Shield or Raspberry Pi Hat form factors:

Motoron motor controllers Arduino and Raspberry Pi form factor versions
	M3S550 M3H550	M3S256 M3H256	M2S24v14 M2H24v14	M2S24v16 M2H24v16	M2S18v18 M2H18v18	M2S18v20 M2H18v20
Control interface:	I²C
Motor channels:	3 (triple)		2 (dual)
Minimum motor supply voltage:	1.8 V	4.5 V	6.5 V
Absolute max motor supply voltage:	22 V	48 V	40 V		30 V
Recommended max nominal battery voltage:	16 V	36 V	28 V		18 V
Max continuous current per channel:	1.7 A	2 A	14 A	16 A	18 A	20 A
Available versions for Arduino:	M3S550 assembled kit board only	M3S256 assembled kit board only	M2S24v14 assembled kit board only	M2S24v16 assembled kit board only	M2S18v18 assembled kit board only	M2S18v20 assembled kit board only
Available versions for Raspberry Pi:	M3H550 assembled kit board only	M3H256 assembled kit board only	M2H24v14 assembled kit board only	M2H24v16 assembled kit board only	M2H18v18 assembled kit board only	M2H18v20 assembled kit board only
Price:	$20.95 – $30.95	$34.95 – $44.95	$59.95 – $69.95	$115.95 – $124.95	$59.95 – $69.96	$95.95 – $104.95

The great thing about the Motorons is that you can easily string together or stack multiple controllers, mixing and matching sizes to fit your application. For example, you could use one high-power dual motor version for drive motors on a mobile robot and then add a smaller 3-channel motor controller for additional actuators. This arrangement with three stacked Motorons on an Arduino Uno allows simple control of up to 9 motors:

The common protocol between versions also makes it easy to change motor sizes and to reuse your code between projects. Want to make a bigger version of your first prototype? Just use a higher-power Motoron! Want to make a tiny robot next time? Use a tiny Motoron! Want to… you get the idea.

While the 3-channel boards are designed to stack on Arduinos or Raspberry Pis, they are also easy to use on breadboards:

It may be easy to view the six new Mxx550 Motorons as just lower-voltage versions of the previously available Mxx256 Motorons, but I am especially excited about them because we are able to offer them at a very low price, extending the legacy of the Dual Serial Motor controllers that were among our first products over 20 years ago. We are launching the 2-channel M2T550 and M2U550 at just $15.95, a lower price than the original Dual Serial Motor controller from 2001 (without even adjusting for inflation!).

The chip shortages of the past several years have made it especially difficult to introduce new products and to keep their prices down, but things are finally seeming to get better on that front. You can see in the tables above that the higher-power 2-channel Motorons are much more expensive; those prices are still elevated because we are limited on some critical components we use there and in our other products. We should be able to manufacture plenty of the new Motorons without being constrained in a similar way.

Related products

	Motoron M3S550 Triple Motor Controller Shield for Arduino (Connectors Soldered)
	Motoron M3S550 Triple Motor Controller Shield Kit for Arduino
	Motoron M3S550 Triple Motor Controller Shield for Arduino (No Connectors)
	Motoron M3H550 Triple Motor Controller for Raspberry Pi (Connectors Soldered)
	Motoron M3H550 Triple Motor Controller Kit for Raspberry Pi
	Motoron M3H550 Triple Motor Controller for Raspberry Pi (No Connectors or Standoffs)
	Motoron M2T550 Dual I²C Motor Controller (Header Pins Soldered)
	Motoron M2T550 Dual I²C Motor Controller
	Motoron M2U550 Dual Serial Motor Controller (Header Pins Soldered)
	Motoron M2U550 Dual Serial Motor Controller
	Motoron M1T550 Single I²C Motor Controller (Header Pins Soldered)
	Motoron M1T550 Single I²C Motor Controller
	Motoron M1U550 Single Serial Motor Controller (Header Pins Soldered)
	Motoron M1U550 Single Serial Motor Controller

I am super excited to introduce our newest robot, the 3pi+ 2040. This robot combines the 3pi+ chassis, which we initially released in late 2020, with the power of the Raspberry Pi RP2040 microcontroller. Here is a quick overview of its features:

This summer will mark 15 years since we released our original 3pi robot, which was designed to be fast enough to be competitive in line following and maze solving events. The high speed offers interesting programming challenges not present in typical robot kits of that era; here is a video from back then in which Ben demonstrates his 3pi learning a maze and then going extra fast on longer straightaways:

Although we developed our first injection-molded parts (wheels, ball caster, and motor mounting brackets) for that design, it was still largely a “PCB on wheels” kind of robot. The next-generation 3pi+, with a chassis mechanically independent of any circuit board, had been in development for several years when the coronavirus pandemic hit in early 2020. We kept working on it throughout that year, culminating with the November release of the 3pi+ 32U4.

Original Pololu 3pi robot.

3pi+ 32U4 Robot.

The 3pi+ delivered the most-requested feature missing from the 3pi, wheel encoders, along with many other improvements including a full IMU, bumpers, and programmability over USB (the 3pi required an external AVR programmer). With its support in the Arduino environment, the ATmega32U4 continues to offer a good entry point for working with microcontrollers, but the 8-bit architecture and 32 KB of program memory feel increasingly outdated and constraining, especially with the new sensors available on the 3pi+.

That brings us to the new 3pi+ 2040, powered by the Raspberry Pi RP2040 microcontroller (32-bit dual-core Arm Cortex-M0+) with 16 MB (128 Mbit) of flash memory. The robot ships preloaded with a MicroPython interpreter, so you can get started right away by plugging into its USB C port and editing the included example Python programs with your favorite text editor. No special programmers or programming software are required, and you can write MicroPython code from practically any desktop or mobile operating system as long as it has a text editor and the ability to copy files to a USB drive. For a basic Python IDE that lets you run code interactively, we are recommending the Mu editor. (See the User’s Guide for instructions on setting it up.)

MicroPython drive showing 3pi+ 2040 demo programs.

The blink.py demo program in a text editor.

There are many other programming environments and languages that you can use with the 3pi+. Since it shares the same RP2040 processor as the Raspberry Pi Pico, anything that works for the Pico should be usable on the 3pi+, including C, C++, and the Arduino environment. We already include some basic C examples in our example code repository, and we plan to write more examples and expand the software support for this robot. Do you have a favorite IDE that works with the Pico? Is there some language or system you’d like to run on the 3pi+?

The menu of pre-installed demo programs on the 3pi+ 2040 Robot.

Early adopter special: We are initially offering the 3pi+ 2040 Robot as a limited release intended for advanced customers who have had some experience with robotics or Raspberry Pi RP2040 programming (e.g. with a Raspberry Pi Pico). The initial release is available with 30:1 MP motors (the “Standard Edition”), either assembled for 38% off or in kit form for 50% off. Early adopter robots will generally need to be backordered as they are built to order; we expect to ship within a business day of ordering. The robot hardware is finalized so the only changes we expect for the full product release are in the initial firmware configuration and pre-installed example programs. Documentation will also continue to be developed as we release the robot to a wider customer base. Early adopters who publicly share their 3pi+ 2040 experiences will be eligible for an additional robot with an extra $25 discount.

Related products

	3pi+ 2040 Robot - Standard Edition (30:1 MP Motors), Assembled
	3pi+ 2040 Robot Kit with 30:1 MP Motors (Standard Edition Kit)
	Pololu 3pi Robot