News from the USB DAC + Headphone Amp project by Yin Zhong (summivox):
In the interim update post I posted the plan for integration into 2 boards: A 2-layer power board, and a 4-layer main board. Actually I have had a good copy of the main board for quite a while: Story for the power board is not as good though. In the beginning I screwed up on […]
An update from the USB DAC + Headphone Amp project by Yin Zhong (summivox):
Months into the project and I was still amazed at the lack of availability of a class of ASICs: USB-I2S bridges. Well I just lied — if you are fine with USB 1.1 and USB Audio Class (UAC) 1.0, which severely limits your (bit depth × resolution × channel count)
So I kept looking for ASICs, and I found one that is close enough: XMOS XHRA-2HPA. It even comes with a reference design that does exactly what I want!
summivox has shared the board on OSH Park:
Eric Brombaugh designed this breakout board for the Rafael Microelectronics R820T2 Advanced Digital TV Silicon Tuner chip:
This is the same chip used in most all of the RTL-SDR dongles, as well as the Airspy and numerous other radios. The chip is a versatile front-end with reasonable sensitivity and wide tuning range.
The design presented here is almost an exact implementation of the Mfg’s suggested demo design from the datasheet, implemented on the OSHpark 4-layer PCB process and provides a simple 4-pin interface with power, ground and I2C bus for controlling the tuner. A broad-band RF input and 10MHz IF output are provided on SMA connectors.
The breakout PCB design and STM32F0 firmware for the Rafael R820T2 tuner chip are shared on GitHub:
emeb/r820t2
emeb has shared project on OSH Park:
From the Pluxx’s Magitech Golem Parts Emporium blog:
This is a breakout board for the Intersil ISL12022M real-time clock, with optional I²C pull-ups and a CR1225 backup battery. The circuit is based on the design recommended by Intersil, with a few tweaks. It’s the second board I’ve designed so far.
golemparts has shared the project on OSH Park:
Brian Solon designed this compact board to add an Adafruit 2.2″ TFT LCD display to the Raspberry Pi Zero:
The design files are available on GitHub:
pi-zero-tft-adapter
From the Intelligent Toasters blog:
I’ve been working on, replacing the NAND raw flash with an eMMC chip on the CPC2.0 board.
I wrote about raw flash and the challenges of writing a flash translation later in part 16 of this series. After some research, I concluded that the eMMC interface looked exactly like the much more common SDCard interface, albeit that the interface can be run with an 8-bit width. SDCards are limited to 4 bits by the physical pin count. Taking a gamble I created a board to test this new eMMC chip. I created a fake SDCard!
This fake card allowed me to check very quickly if my assumptions were correct both at a hardware and a firmware level. I wanted to be sure that it was possible to interface the eMMC via 4 bits, rather than the full 8 bits and be sure the firmware instructions were the same between these two technologies.
Intelligent-Toasters has shared the board on OSH Park:
Dan Hienzsch a holiday project to build a little Snowbot with an adjustable speed larson scanner for an eye:
When I started thinking of this project, I wanted to make something that included a bit of the basics and something more advanced. It had to be battery powered, and most importantly, I wanted to make sure it went against the grain of everything needing a microcontroller. Thus Snowbot was born.
Photos from the Hackaday.io project:
RheingoldHeavy has shared the board on OSH Park:
UPDATE: Check out the new version with pull-up resistors
I designed this simple breakout board in KiCad to make it easier to put a rotary encoder on a breadboard. The KiCad symbol and footprint for the SparkFun rotary encoder was created by mcous on GitHub. I used an updated version with corrected pin numbering.
Here are the rotary encoders that I’ve verified to fit:
The design files are available on GitHub:
pdp7/rotary-encoder-breakoutThe board is shared on OSH Park:
Black Mesa Labs created this board that adds a Lattice FPGA to a Raspberry Pi:
BML has been very much enchanted with the Lattice FPGA boards for Raspberry Pi, IcoBoard , BlackIce and IceHat. The IceZero board is a BML creation that attempts to combine the best features of all 3 boards into a single design.
IceZero features common with other designs
IceZero features that are BML specific
BlackMesaLabs has shared the board on OSH Park:
BML IceZero Lattice ICE40 FPGA for RaspPi
My Omega2 Onion shield, using a AMS1117 for 3.3V and CH340G for USB to serial. Kind of ugly soldering here as I didn’t have a tip for the syringe to dispense solder paste, so I just smeared it all over and hoped it reflowed well. It kind of did, but I had a solder blob short on pin 14 +15 on the CH340G, so I just lifted those two legs off the board. I was so eager to get this board tested that I forgot to check that I had these 2mm pin headers. I had just enough to get this thing tested. Time to order more 🙂
Jensa has shared the board on OSH Park:
Simple breakout board using the dirt cheap IC’s CH340G ($0.30/each on ebay) for Serial and a AMS1117-3.3 ($0.025/each) for power. Breaks out all pins from 2mm to 2.54mm headers. Plugs nicely into two small breadboards for prototyping.
OSH Park 