[Andrew Milkovich] was inspired build his own Super Nintendo cartridge reader based on a device we covered an eternity (in internet years) ago. The device mounts a real cartridge as a USB mass storage device, allowing you to play your games using an emulator directly from the cart.
This uses a Teensy++ 2.0 at its core. [Andrew] had to desolder the EEPROM pins from the SNES cartridge and reverse engineer the pinouts himself, but the end result was a device that could successfully read the cartridge without erasing it, no small accomplishment. The finished cartridge reader is build on some protoboard and we’d like to complement [Andrew] on his jumper routing on the underside of that board.
Of course, the experience of any console is just not the same without the original controller. So [Andrew] went a step further and made his own SNES controller to USB converter. This had the venerable Atmel ATmega328 at its core, and can be used separate from the cartridge reader if desired.
“Round up the usual suspects…”
[CNLohr] just can’t get enough of the ESP8266 these days — now he’s working on getting a version of V-USB software low-speed USB device emulation working on the thing. (GitHub link here, video also embedded below.) That’s not likely to be an afternoon project, and we should warn you that it’s still a project in progress, but he’s made some in-progress material available, and if you’re interested either in USB or the way the mind of [CNLohr] works, it’s worth a watch.
In this video, he leans heavily on the logic analyzer. He’s not a USB expert, and couldn’t find the right resources online to implement a USB driver, so he taught himself by looking at the signals coming across as he wiggled a mouse on his desk. Using the ever-popular Wireshark helped him out a lot with this task as well. Then it was time to dig into Xtensa assembly language, because timing was critical.
Speaking of timing, one of the first things that he did was write some profiling routines so that he could figure out how long everything was taking. And did we mention that [CNLohr] didn’t know Xtensa assembly? So he wrote routines in C, compiled them using the Xtensa GCC compiler, and backed out the assembly. The end result is a mix of the two: assembly when speed counts, and C when it’s more comfortable.
Continue reading “[CNLohr], ESP8266, USB…”
The Raspberry Pi is a great computer, even if it doesn’t have SATA. For those of us who have lost a few SD cards to the inevitable corruption that comes from not shutting a Pi down properly, here’s something for you: USB Mass Storage Booting for the Raspberry Pi 3.
For the Raspberry Pi 1, 2, Compute Module, and Zero, there are two boot modes – SD boot, and USB Device boot, with USB Device boot only found on the Compute Module. [Gordon] over at the Raspberry Pi foundation spent a lot of time working on the Broadcom 2837 used in the Raspberry Pi 3, and found enough space in 32 kB to include SD boot, eMMC boot, SPI boot, NAND flash, FAT filesystem, GUID and MBR partitions, USB device, USB host, Ethernet device, and mass storage device support. You can now boot the Raspberry Pi 3 from just about anything.
The documentation for these new boot modes goes over the process of how to put an image on a USB thumb drive. It’s not too terribly different from the process of putting an image on an SD card, and the process will be streamlined somewhat in the next release of
rpi-update. Some USB thumb drives do not work, but as long as you stick with a Sandisk or Samsung, you should be okay.
More interesting than USB booting is the ability for the Pi 3 to boot over the network. Booting over a network is nothing new – the Apple II could do it uphill both ways in the snow, but the most common use for the Pi is a dumb media player that connects to all your movies on network storage. With network booting, you can easily throw a Pi on a second TV and play all that media in a second room. Check out the network booting tutorial here.
[Aleksejs Mirnijs] needed a tool to accurately measure the power consumption of his Raspberry Pi and Arduino projects, which is an important parameter for dimensioning adequate power supplies and battery packs. Since most SBC projects require a USB hub anyway, he designed a smart, WiFi-enabled 4-port USB hub that is also a power meter – his entry for this year’s Hackaday Prize.
[Aleksejs’s] design is based on the FE1.1s 4-port USB 2.0 hub controller, with two additional ports for charging. Each port features an LT6106 current sensor and a power MOSFET to individually switch devices on and off as required. An Atmega32L monitors the bus voltage and current draw, switches the ports and talks to an ESP8266 module for WiFi connectivity. The supercharged hub also features a display, which lets you read the measured current and power consumption at a glance.
Unlike most cheap hubs out there, [Aleksejs’s] hub has a properly designed power path. If an external power supply is present, an onboard buck converter actively regulates the bus voltage while a power path controller safely disconnects the host’s power line. Although the first prototype is are already up and running, this project is still under heavy development. We’re curious to see the announced updates, which include a 2.2″ touchscreen and a 3D-printable enclosure.
It probably doesn’t matter much for the hacker who sleeps with a bag of various microcontroller flash programmers under the pillow, but for an end-user to apply a firmware upgrade, convenience is king. These days that means using USB, and there are a few good AVR USB bootloaders out there.
But [Dmitry Grinberg] wanted more: the ability to encrypt the ROM images and verify that they haven’t been tampered with or otherwise messed up in transit. Combined with the USB requirement, that meant writing his own bootloader and PC-side tools. His bootloader will take unencrypted uploads if it doesn’t have a password, but if it’s compiled with a key, it will only accept (correctly) encrypted hex files.
Since the bootloader, including the USB firmware, is on the hefty side at 3.3 kB, [Dmitry] included hooks to re-use the bootloader’s USB code from within the target application. So if you were going to use V-USB in your program anyway, it doesn’t actually take up that much extra space. It’s a cute trick, but it ties the bootloader and user program together in a way that gives us the willies, without specifically knowing why. Perhaps we can debate this in the comments.
If you need an AVR USB bootloader, but you don’t need the encryption, we like Micronucleus. But if you need to deliver updates to users without them being able to modify (or screw up) the code in the middle, give [Dmitry]’s setup a try.
Every hacker has a USB thumb drive on their keyring, filled with backup files and a way to boot up a broken computer. One feature that most are missing though is USB On The Go (OTG) support, which allows a USB device to act as a USB host, connecting to devices like cell phones and tablets.
That can be added with the addition of a USB OTG adapter, though, and [usbdevice] has produced a nice how-to on soldering one of these permanently into a USB thumb drive to create a more flexible device. It’s a simple solder-something-on-something-else hack, but it could be handy.
There are a few caveats, though: it needs a USB thumb drive with solderable headers, which most of the smallest drives that have connectors right on the PCB won’t have. Most of the larger drives will have these, though, and they are cheap, so finding a suitable victim isn’t hard.
There are a ton of applications that we use that can benefit from keyboard shortcuts, and we use ’em religiously. Indeed, there are some tasks that we do so often that they warrant their own physical button. And the only thing cooler than custom keyboards are custom keyboards that you’ve made yourself.
Which brings us to [Dan]’s four-button Cherry MX USB keypad. It’s not really all that much more than four keyswitch footprints and an AVR ATmega32u4, but that plus some software is all you really need. He programs the Arduino bootloader into the chip, and then he’s using the Arduino Leonardo keyboard libraries. Bam! Check out the video below.
Continue reading “Quickie USB Keyboard Device”