Session 3 - 15 March 2016
- 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.
Transducer for a reflection
Pulser: the HV7360
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