the up5k lit3rick open hardware ultrasound pulse echo board

Presentation of the hardware

• Lattice: up5k. Onboard RAM for 64k points saves.
• Onboard flash : W25X10CLSNIG
• Pulser : HV7361GA-G: adaptable to +-100V pulses. Onboard is 5V pulse.
• AD8331 for gain
• ADC: AD9629BCPZ-65: 12bits, reaching 64Msps here
• DAC: MCP4812-E/MS for 8us gain segments

Content

• Hardware files. Stemming from the forkable upverter design.
• Utilities to program the up5k: no FTDI, all through the RPi header, using its SPI bus to program either the board flash, or the fpga directy.
• The python tools: to facilitate the acquisitions.
• The cursed gateware: for the current gateware linked to the python library.

Some images, unipolar pulse at Vpulse = 5V

Python setup

An example from the py_fpga folder, summarized. Check the visualisation of the acquisitions below.

# Setting the fpga buses
fpga = py_fpga(i2c_bus=i2c_bus, py_audio=p, spi_bus=spi)

# Setting the 
fpga.set_waveform(pdelay=1, PHV_time=11, PnHV_time=1, PDamp_time=100)

# Setting the gain values
hiloVal = 1 # High or low.
dacVal = 250 # on a range from 0 to 512
fpga.set_HILO(hiloVal)
fpga.set_dac(dacVal)

# Setting the VGA
startVal,nPtsDAC = 250, 16
for i in range(nPtsDAC):
	fpga.set_dac(int(startVal + (i*(455-startVal))/nPtsDAC), mem=i)

# Reading 10 successive acquisitions
dataI2S = fpga.read_fft_through_i2s(10)

# Getting the detailed buffer (8192pts at 64msps)
dataSPI = fpga.read_signal_through_spi()

# "Manually" calculating the FFT and reading it
fpga.calc_fft() 
time.sleep(3/1000.0) # normally takes ~800us to compute 8192pts
dataFFT = fpga.read_fft_through_spi()

Content of the dataI2S

Content of the dataSPI

Content of the dataFFT

Efficiency of enveloppe extraction and compression

Benchmarking

Benchmarking against the un0rick board

Checking the level of noise in each board, at max gain (no transducer plugged).

License

This work is based on two previous TAPR projects, the echOmods project, and the un0rick project - its boards are open hardware and software, developped with open-source elements as much as possible.

Copyright Kelu124 (kelu124@gmail.com) 2020.

• The hardware is licensed under TAPR Open Hardware License (www.tapr.org/OHL)
• The software components are free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
• The documentation is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.

Disclaimer

This project is distributed WITHOUT ANY EXPRESS OR IMPLIED WARRANTY, INCLUDING OF MERCHANTABILITY, SATISFACTORY QUALITY AND FITNESS FOR A PARTICULAR PURPOSE.