Bus Pirate “Ultra” HDL moves from simulation to real hardware

Latest simulation of Bus Pirate Ultra HDL

The HDL is complete enough to start testing on real hardware. This update puts almost every feature under control of the state machine in the FPGA so commands can be pipelined with repeatable precision. Commands (write/read SPI, set/clear pin, measure voltage, update PWM, enable pull-up resistors, etc) are pushed into a FIFO buffer using a 17bit command/data protocol inspired by the interface of ST7789-based LCDs. When the state machine is enabled the commands are processed in one continuous stream.

Verilog HDL for the FPGA is on github, the latest updates are currently on the command-data-refactor branch. A synthesized version of the bitstream is in the forum.

giggiu16 has already build a v1d. There are a few more boards to give away, if you’d like one please message Ian in the forum.

Homemade injection transformer for PSU loop analysis

Adil Malik made a DIY injection transformer for PSU loop analysis:

Recently, I have been designing some SMPS and required some hardware to measure the actual loop response of the complete converters. People familiar with this area will probably know this can be done breaking the feedback loop of the converter and injecting a small AC signal and measuring the loop response at the output of the converter. However, such a measurement requires a mechanism to inject this signal differential across a small resistor inline with the normal feedback network. Unfortunately, as most signal generators are ground referenced we need special hardware to convert this output to a floating output.
Commercial PSU analysers come with expensive injection transformers that allow us to do that. These transformers are designed to have a very flat response in the region of conventional loop bandwidths of SMPS converters, these range from a few Hz to upto a few MHz.

See the full post on DIY projects of an EE student blog.

Nano controlled step attenuator

VE3POA writes:

DuWayne KV4QB, has done a Step Attenuator project and was kind enough to give me a board he designed for it at FDIM this year. So, I will not reinvent the wheel here and follow his design. Thank you DuWayne. Here’s a link to his blog where you can read not only about his attenuator project but other great things he has done. kv4qb.blogspot.com
As is with DuWayne’s project, I’ll use 2 pe4302 boards connected in series with the control lines in parallel. This will mean that the attenuator steps will be in 1dB increments which is fine for anything I’ll require. Max power input is +24dbm which is again fine for my purposes.

More details on this blog At the Electronic’s Workbench of VE3POA.

Building a Power-over-Ethernet (PoE) power supply using a DPS5005 module

Dr. Scott M. Baker has designed and built a PoE-powered lab power supply using a DPS5005 and custom PoE board:

The DPS5005 is a DC-DC converter. It can accept an input voltage from 0 to about 55 volts or so, and will regulate an output voltage up to about 1 volt below the input. This version is good to 5 amps, but there are other versions of this supply that will do as little as 30V / 2A and as much as 50V / 20A. 50V 5A seems like a good sweet spot. Since it is a DC-DC converter, you have to have a DC source to drive it. A lot of people use a 48V power brick, as they are commonly available.

Project info at smbaker.com.

Check out the video after the break.

An ATmega brushless sensorless motor driver v02

Davide Gironi has posted an update on his ATmega brushless sensorless motor driver project we covered previously:

Brushless electric motor (BLDC motors) are synchronous motors that are powered by a DC electric source via an integrated inverter/switching power supply, which produces an AC electric signal to drive the motor.

See the full post on his blog here.

Check out the video after the break.

App note: Assembly guidelines for QFN (quad flat no-lead) and SON (small outline no-lead) packages

NXP’s app note about the internals and how to’s footprint design and solder their leadless dual and quad flat packages. Link here (PDF)

The small outline no-lead (SON)/quad flat no-lead (QFN) is a small size, lead-less plastic package with a low profile, moderate thermal dissipation, and good electrical performance. It is a surface mount package with metallized terminal pads located at the bottom surface of the package. SON have terminal pads along two opposite edges of the package versus QFN with terminal pads along the four edges of the bottom surface. SON is sometimes also referred as DFN: Dual flat no-lead package.