Session 3 - 15 March 2016

Other sessions

  • Session 1 : Powering the board, power use, first (bad) trigging and echoes (06 March 2016)
  • Session 2 : Non-controlled pulsing, inverters, better echoes (11 March 2016)
  • Session 3 : Getting controlled pulsing, but width not controlled (15 March 2016)
  • Session 4 : Width of the pulses is getting controlled =) (19 March 2016)
  • Session 4b : Simple data visualisation with BitScope (19 March 2016)
  • Session 5 : moving the transducer to get the first image (20 March 2016)
  • Session 6 : Getting a clinically usable image (28 March 2016)
  • Session 7 : Getting cleaner images - code improvements (3 April 2016)
  • Session 8 : Comparing acquisition speeds (3 May 2016)



Getting nicer pulses.


  • Managed to switch on and off the HV with USPP and USPN.
  • With a 7.5us wide pulse, we see two echoes separated by 7.5us, hence the double echoes for switching on and off the transducer.

Technical points


Overall setup

Transducer for a reflection

Pulser: the HV7360

  • Same setup as Session 1 and Session 2.

  • The issue is that the two pulses were not controlled.. so we'll need to find something to synchronise these two, with a 150ns delay..

Discussion and issues


  • High pulses: from a small pulse, echoes are amplified to a 1.54V , on an average of ~0V.

  • Need to get a better pulser!


  • Tests were done without having put the DAC inputs to GND. That may lead to some issues in reproductibility.
  • Need to document the role of Jumper 1 more precisely.
  • Let's try to get images from only 2/3, trigging from an external source? -- Without SPI control of the DAC -- With SPI
  • We can't get anything at the TP 5/6 signal..


Moving along the chain of capture

Before the MD0100

After the MD0100

After the LC after the MD0100

After the TGV (points 2/3) with Jumper on gain low

After the TGV (points 2/3) with Jumper on gain high

Before the transformer (TP 5/6)

Controlling the pulse width

Trigging without USPN

Triggin with USPN

Details of the controls

Trigging on with USPP

Trigging off with USPN

Plugging the transducer

Trigging without transducer

Trigging with the transducer

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