- FPGA: Lattice UP5K. Onboard RAM for 64k points saves.
- Onboard flash : W25X10CLSNIG
- Pulser : HV7361GA-G: can manageg up to +-100V pulses. Onboard is 5V pulse.
- AD8331 for gain - ~40dB gain.
- ADC: AD9629BCPZ-65: 12bits, reaching 64Msps here
- DAC: MCP4812-E/MS for 8us gain segments
- 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.
- R26 is to be removed if we are using two transducers or one transducer with on element. Am i right?
- To separate TX/RX, indeed that’s R26 that should be removed.
- 5V/GND: What is used for? HV +/- must be use if we want to use an external voltage supply for the pulses?
- You can put two jumpers on the two 2x1 headers, so that 5V is connected to [HV+] source, and [HV-] is on GND. HV+ can accomodate [0 : 100V], and HV- can take [-100:0V].
- I guess “From Piezzo” and “SMA RX” are the same, with just a different connection. Is that right? Same thing for “To Piezzo” and “SMA TX”?
- “ToPiezo” is indeed the TX path, FromPiezo the RXPath.
- If we are using only one transducer for both TX and RX, how do we have to connect it?
- By default, the TX and RX SMAs are connected (with R26, a 0R). So you can only put in place one SMA an connect this piezo to this SMA.
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()
# Changelog / TODO
- v1.1ca (not released)
- Put in AD8332
- Add external clock
- Expose gain pad
- Think of a FTDI+HV daughter board
- v1.0 initial release
- 12bits ADC
- i2s connections, along with i2c and spi, + uart (on buttons)
- TODO: still some finetuning with i2s streaming (slight offset over long period)
Copyright Kelu124 (firstname.lastname@example.org) 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.
This project is distributed WITHOUT ANY EXPRESS OR IMPLIED WARRANTY, INCLUDING OF MERCHANTABILITY, SATISFACTORY QUALITY AND FITNESS FOR A PARTICULAR PURPOSE.