Espressif Introduces The ESP32-E22 Wi-Fi 6E And Bluetooth Co-Processor

Espressif has unveiled its latest major chip in the form of the ESP32-E22. Officially referred to as a Radio Co-Processor (RCP), it’s intended to be used via its PCIe 2.1 or SDIO 3.0 host interface to provide wireless communications to an SoC or similar.

This wireless functionality includes full WiFi 6E functionality across all three bands, 160 MHz channel bandwidth and 2×2 MU-MIMO, making it quite a leap from the basic WiFi provided by e.g. the ESP32-S* and -C* series. There is also Bluetooth Classic and BLE 5.4 support, which is a relief for those who were missing Bluetooth Classic in all but the original ESP32 for e.g. A2DP sinks and sources.

The ESP32-E22 processing grunt is provided by two proprietary Espressif RISC-V CPU cores that can run at 500 MHz. At this point no details appear to be available about whether a low-power core is also present, nor any additional peripherals. Since the graphics on the Espressif PR article appear to be generic, machine-generated images – that switch the chip’s appearance from a BGA to an LQFP package at random – there’s little more that we can gather from there either.

Currently Espressif is making engineering samples available to interested parties after presumed vetting, which would indicate that any kind of public release will still be a while off. Whether this chip would make for an interesting stand-alone MCU or SoC along the lines of the -S3 or -P4 will remain a bit of a mystery for a bit longer.

Thanks to [Rogan] for the tip.

What To Do With A Flash-less ESP32-C3 Super Mini Board?

In an update video by [Hacker University] to an earlier video on ESP32-C3 Super Mini development boards that feature a Flash-less version of this MCU, the question of adding your own Flash IC to these boards is addressed. The short version is that while it is possible, it’s definitely not going to be easy, as pins including SPIHD (19) and SPICLK (22) and SPIQ (24) are not broken out on the board and thus require one to directly solder wires to the QFN pads.

Considering how sketchy it would be to have multiple wires running off to an external Flash IC, this raises many questions about the feasibility, as well as cost-effectiveness. Some in the comments to the video remark that instead you may as well swap the MCU with a version that does contain built-in Flash, but this is countered with the argument that a new ESP32-C3 Super Mini board with the right MCU costs as much as a loose MCU from your favorite purveyor of ICs.

Ultimately this lends some credence to calling these zero Flash Super Mini boards a ‘scam’, as their use cases would seem to be extremely limited and their Flash-less nature very poorly advertised.

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WCH CH32M030: Another Microcontroller To Watch Out For

One of the joys of writing for Hackaday comes in following the world of new semiconductor devices, spotting interesting ones while they are still just entries on manufacturer websites, and then waiting for commonly-available dev boards. With Chinese parts there’s always a period in which Chinese manufacturers and nobody else has them, and then they quietly appear on AliExpress.

All of which brings us to the WCH CH32M030, a chip that’s been on the radar for a while and has finally broken cover. It’s the CH32 RISC-V microcontroller you may be familiar with, but with a set of four half-bridge drivers on board for running motors. A handy, cheap, and very smart motor controller, if you will.

There’s been at  least one Chinese CH32M030 dev board (Chinese language) online for a while now, but the one listed on AliExpress appears to be a different design. At the time of writing the most popular one is still showing fewer than 20 sales, so we’re getting in at the ground floor here.

We think this chip is of interest because it has the potential to be used in low price robotic projects, replacing as it does a couple of parts or modules in one go. If you use it, we’d like to hear from you!

Looking At A Real Fake Raspberry Pi RP2040 Board

Since the RP2040 microcontroller is available as a stand-alone component, it’s easy enough for third parties to churn out their own variations — or outright clones of — the Raspberry Pi Pico. Thus we end up with for example AliExpress sellers offering their own versions that can be significantly cheaper than the genuine article. The ones that [electronupdate] obtained for a test and decapping session cost just $2.25 a pop.

RP2 B0 stepping imprinted on the die shot.

As can be seen in the top image, the board from AliExpress misses the Raspberry Pi logo on the silkscreen for obvious reasons, but otherwise appears to feature an identical component layout. The QSPI Flash IC is marked on the die as BY250156FS, identifying it as a Boya part.

Niggles about flash ROM quality aside, what’s perhaps most interesting about this teardown is what eagle-eyed commentators spotted on the die shot of the RP2040. Although on the MCU the laser markings identify the RP2040 as a B2 stepping, the die clearly identifies it as an ‘RP2 B0’ part, meaning B0 stepping. This can be problematic when you try to use the USB functionality due to hardware USB bugs in the B0 and B1 steppings.

As they say, caveat emptor.

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A pair of glass vacuum tubes can be seen on a workbench, each with complex copper structures inside. One is mounted on top of a metal chassis with a motor and some other circuitry visible.

Taking A Look At Variable Vacuum Capacitors

Variable capacitors may be useful, but the air gap that provides their capacitance is their greatest weakness. Rather than deal with the poor dielectric properties of air, some high-end variable capacitors replace it with a vacuum, which presents some obvious mechanical difficulties, but does give the resulting capacitor a remarkable quality factor, high-voltage performance, and higher capacitance for plate area than their air-gapped brethren. [Shahriar] of [The Signal Path] managed to acquire a pair of these and took a detailed look at their construction and performance in a recent video.

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An LDO schematic and some notes about their features

Texas Instruments Explain Low-Dropout Linear Voltage Regulators

Today in power electronics, the folks over at Texas Instruments have put together a video covering low-dropout (LDO) linear regulators.

For a hacker, power is pretty fundamental, so it behooves us to know a little bit about what our options are when it comes time to regulate power to our projects. In this video [Alex Hanson] from Texas Instruments runs us through the linear voltage regulators known as low-dropout regulators (LDOs). It turns out that LDOs are often a poor choice for voltage regulation because they are inefficient when compared to switching regulator alternatives and can be more expensive too.

So when might you use an LDO? In very low power situations where heat and efficiency doesn’t matter very much. LDOs operate best when the input voltage is very near the output voltage and when current demands are low (roughly speaking less than ~50 mA is okay, ~500 mA is maximum, and some applications will support 1 to 3 A, although not with great efficiency and in this case thermal emissions — or magic smoke! — will become an issue).

What LDOs bring to the table is relatively clean and low-noise voltage as well as low dropout voltage (the minimum difference between the input and output voltage needed for regulation), which is their defining feature. What’s more with an appropriate output capacitor they can react quickly to load changes and they usually emit minimal EMI. LDOs are not about efficiency, they are about quality, simplicity, and control.

You might like to read more about when linear regulators might be the right choice or what your other options are.

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The Cutting Truth About Variable Capacitors

If you’ve seen a big air-variable capacitor, you may have noticed that some of the plates may have slots cut into them. Why? [Mr Carlson] has the answer in the video below. The short answer: you can bend the tabs formed by the slots to increase or decrease the capacitance by tiny amounts for the purpose of tuning.

For example, if you have a radio receiver with a dial, you can adjust the capacitor to make certain spots on the dial have an exact frequency. Obviously, you can only adjust in bands depending on how many slots are in the capacitor. Sometimes the adjustments aren’t setting the oscillator’s frequency. For example, the Delco radio he shows uses the capacitor to peak the tuning at the specified frequency.

You usually only find the slots on the end plates and, as you can see in the video, not all capacitors have the slots. Of course, bending the plates with or without slots will make things change. Just don’t bend enough to short to an adjacent plate or the fixed plates when the capacitor meshes.

Of course, not all variable capacitors have this same design. We’ve seen a lot of strange set ups.

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