The Onion Tau LiDAR Camera is a small, time-of-flight (ToF) based depth-sensing camera that looks and works a little like a USB webcam, but with a really big difference: frames from the Tau include 160 x 60 “pixels” of depth information as well as greyscale. This data is easily accessed via a Python API, and example scripts make it easy to get up and running quickly. The goal is to be an affordable and easy to use option for projects that could benefit from depth sensing.
When the Tau was announced on Crowd Supply, I immediately placed a pre-order for about $180. Since then, the folks at Onion were kind enough to send me a pre-production unit, and I’ve been playing around with the device to get an idea of how it acts, and to build an idea of what kind of projects it would be a good fit for. Here is what I’ve learned so far.
As mildly exotic silicon has become cheaper and the ingenuity of hardware hackers has been unleashed upon it, it’s inevitable that some once-unattainably expensive instruments will appear as cheap modules from China. The LTDZ spectrum analyser on the bench today covers 35 MHz to 4.4 GHz, and has a USB interface and tracking source. It has been available from all the usual outlets for a while now either as a bare PCB or in a metal box about the size of a pack of cards.
We’ve already taken a look at the $50 VNA, and this time it’s the turn of the $30 spectrum analyser, in the form of a little device that I succumbed to while browsing Banggood.
I ordered one, along with an attenuator and RF bridge for SWR measurements, and after the usual wait for postage my anonymous grey package arrived and it was time to give it a look and consider its usefulness. It’s a design derived from one published in Germany’s Funkamateur (“amateur radio”) magazine early in the last decade, and unscrewing the end plate to slide out the board from its extruded enclosure we can see what makes it tick. Continue reading “What Can A $30 USB Spectrum Analyser Do For Me?”→
Most of us have, or, would like to have a 3D printer, a laser engraver, and a CNC machine. However, if you think about it naively, these machines are not too different. You need some way to move in the XY plane and, usually, on the Z axis, as well.
Sure, people mount extruders on CNCs, or even lasers or Dremel tools on 3D printers. However, each machine has its own peculiarities. CNCs need rigidity. 3D printers should be fast. Laser engravers and CNCs don’t typically need much Z motion. So common sense would tell you that it would be tough to make a machine to do all three functions work well in each use case. [Stefan] thought that, too, until he got his hands on a Snapmaker 2.0.
As you can see in the video below, the machine uses different tool heads for each function. The motion system stays the same and, curiously, there are three identical linear motion modules, one for each axis.
We just got our hands on some engineering pre-samples of the ESP32-C3 chip and modules, and there’s a lot to like about this chip. The question is what should you compare this to; is it more an ESP32 or an ESP8266? The new “C3” variant has a single 160 MHz RISC-V core that out-performs the ESP8266, and at the same time includes most of the peripheral set of an ESP32. While RAM often ends up scarce on an ESP8266 with around 40 kB or so, the ESP32-C3 sports 400 kB of RAM, and manages to keep it all running while burning less power. Like the ESP32, it has Bluetooth LE 5.0 in addition to WiFi.
Espressif’s website says multiple times that it’s going to be “cost-effective”, which is secret code for cheap. Rumors are that there will be eight-pin ESP-O1 modules hitting the streets priced as low as $1. We usually require more pins, but if medium-sized ESP32-C3 modules are priced near the ESP8266-12-style modules, we can’t see any reason to buy the latter; for us it will literally be an ESP8266 killer.
On the other hand, it lacks the dual cores of the ESP32, and simply doesn’t have as many GPIO pins. If you’re a die-hard ESP32 abuser, you’ll doubtless find some features missing, like the ultra-low-power coprocessor or the DACs. But it does share a lot of the ESP32 standouts: the LEDC (PWM) peripheral and the unique parallel I2S come to mind. Moreover, it shares the ESP-IDF framework with the ESP32, so despite running on an entirely different CPU architecture, a lot of code will run without change on both chips just by tweaking the build environment with a one-liner.
One of these things is not like the other
If you were confused by the chip’s name, like we were, a week or so playing with the new chip will make it all clear. The ESP32-C3 is a lot more like a reduced version of the ESP32 than it is like an improvement over the ESP8266, even though it’s probably destined to play the latter role in our projects. If you count in the new ESP32-S3 that brings in USB, the ESP32 family is bigger than just one chip. Although it does seem odd to lump the RISC-V and Tensilica CPUs together, at the end of the day it’s the peripherals more than the CPUs that differentiate microcontrollers, and on that front the C3 is firmly in the ESP32 family.
Our takeaway: the ESP32-C3 is going to replace the ESP8266 in our projects, but it won’t replace the ESP32 which simply has more of everything when we need it. The shared codebase and peripheral architecture makes it easier to switch between the two when we don’t need the full-blown ESP32. In that spirit, we welcome the newcomer to the family.
But naturally, we’ve got a lot more to say about it. Specifically, we were interested in exactly what the RISC-V core brought to the table, and ran the module through power and speed comparisons with the ESP32 and ESP8266 — and it beats them both by a small margin in our benchmarks. We’ve also become a lot closer friends with the ESP-IDF SDK that all of the ESP32 family chips use, and love how far it has come in the last year or so. It’s not as newbie-friendly as ESP-Arduino, for sure, but it’s a ton more powerful, and we’re totally happy to leave the ESP8266 SDK behind us.
There was a time when decent quality soldering irons were substantial affairs, soldering stations with a chunky base unit containing the electronics and a lightweight handheld iron for the work. That has changed with the arrival of a new breed of microprocessor controlled lightweight handheld irons. There’s a new kid on the block from a company we associate more with open-source phones, laptops, and single board computers, Pine64 have produced the Pinecil. It’s a lightweight handheld iron with some innovative features at an attractive price, but does it raise the bar sufficiently to take on the competition?
Low cost 3D printers have come a long way in the last few years, but have entry-level CNC machines improved by the same leaps and bounds? That’s what [ModBot] recently set out to find. Despite getting burned pretty badly on a cheap CNC a few years back, he decided to try again with a sub $400 machine from FoxAlien. You can see his full review after the break.
The machine looks very similar to other generic CNC machines you see under many brand names, sometimes for a good bit less. The 3018 number is a giveaway that the work area is 30×18 cm and a quick search pulled up several similar machines for just a bit more than $200. The FoxAlien did have a few nice features, though. It has a good-looking build guide and an acrylic box to keep down the shaving debris in your shop. There are also some other nice touches like a Z-axis probe and end stops. If you add those items to the cut-rate 3018 machines, the FoxAlien machine is pretty price competitive when you buy it from the vendor’s website. The Amazon page in the video shows $350 which is a bit more expensive but does include shipping.
As with most of these cheap CNC machines, one could argue that it’s more of an engraver than a full mill. But on the plus side, you can mount other tools and spindles to get different results. You can even turn one of these into a diode laser cutter, but you might be better off with something purpose-built unless you think you’ll want to switch back and forth often.
This reminded us of a CNC we’ve used a lot, the LinkSprite. It does fine for about the same price but we are jealous of the enclosure. Of course, half the fun of owning something like this is hacking it and there are plenty of upgrades for these cheap machines.
I suppose most of us have had the experience of going to the mailbox and seeing that telltale package in the white plastic bag, the sign that something has just arrived from China. This happened to me the other day, and like many of you it was one of those times when I puzzled to myself: “I wonder what I bought this time?”
With so many weeks or months between the time of your impulsive click on the “Buy Now” button on AliExpress or eBay and the slow boat from China actually getting the package to your door, it’s easy enough to forget what exactly each package contains. And with the price of goods so low, the tendency to click and forget is all the easier. That’s not necessarily a good thing, but I like surprises as much as the next person, so I was happy to learn that I was now the owner of a tinySA spectrum analyzer. Time for a look at what this little thing can do.
