device demo
Hi guyz!
So as I promised, this is a demo of the navigating device for the blind, which is based on SigmaDSP. The device imitates bat's cries and is totally ultrasonic. So the reflections, which you will hear are also ultrasonic, just scaled down into the audible range. The amazing thing is that my friend, for whom I have built this thing, can distinguish fabric from glass and glass from paper! Let alone telling the speed of movement and feeling the space. The flip side is that of course navigating like a bat will take prodigious learning. Years most probably. As a bonus I will also include sound of rain, because surprisingly raindrops, if "kicked" with high-frequency ultrasound also produce Doppler shift, which sounds pretty cool. The last one is sound of real bat's cries, which I recorded with the same device, but when it worked in the "natural human range hearing extender" mode. I found out that we are in general literally surrounded by constant ultrasonic noise!! The device is 2.5X4.8cm in size and the heart is adau1701. I just want to say once again lots and lots of "thank you" for all of you guyz, who helped me with advice and with samples. Thank you and thank you again.
P.S. sorry for the noise there - some is ultrasonic noise from my laptop and the white one - a consequence of a really bad line input of my recorder.
Audio Signal Processors
SigmaDSP Audio Processors
adau1701
Hi Skfir,
Thanks for posting the demo, it's amazing! Way more effective than sweeping with a cane. I'm sure your friend will make good use of it.
Bob
Thank Bob! The only bad thing is that since the beam is quite narrow there is no way to see what is under feet. So staircases are indeed undetectable. I will have to come up with some modification. It is actually amazing, how blind people rewire their brain to get visual information out of audial clues. One guy clicks with his tongue and detects cars, gates etc. So I hope if this thing is worn for some years, due to neuroplasticity the brain may adapt, I actually posted a video on youtube with my friend walking etc. So I will post a link here, just if you skip about 6 minutes of my gibberish there will be some demo.
Thats awesome man, could you not add a second sensor and step up to a 144x?
I am thinking about it, but what concerns me is that 144x will need external ADC/DAC and it also eats more power. Since battery power is crucial here, I am a bit concerned. What do you guyz think? Am I wrong and 144x doesn't eat much more? Perhaps there will be an update to 170x series soon?
Hi Skfir,
Have you looked at the ADAU1761? It uses a kernel of the ADAU1442 series DSP, but is geared towards portable devices. It has 2 ADCs and 2 DACs on board, and many of the features of the ADAU1701. The ADAU1442 is not a low-power device, I would not recommend it for a handheld device, as it can draw almost a Watt if the DSP is running a large program, and as you say, you will need a codec as well. How much of the ADAU1701 DSP are you utilizing?
Regards,
Coleman
Hi Coleman!
I use almost the full capacity of 1701 - this is the main problem. I would be willing to add some additional features, but don't have "horse power" left. As far as I know, 1761 doesn't have self-boot mode.
You are correct about the self-boot. Another possibility would be the ADAU1452, which uses about half the power of the ADAU1442 and is a significant upgrade as a DSP. You would need a codec, the ADAU1361 would be a good option. The ADAU1452 will not only self-boot, but it will act as an SPI master and program other parts on the board.
What about power consumption comparing to 1701? Could you please advise about that?
The datasheets specify power dissipation when running typical programs, and they are comparable. It is important to keep in mind that there is a linear relationship between power consumption and DSP use, and the ADAU1452 will be using very little of its processing power to run a similar program to the one you are running in the ADAU1701. I would say that it is worth a look. The EVAL-ADAU1452MINIZ is a simple board that should allow you to analyze the ADAU1452.
Thank you Coleman!! I will give it a try certainly.
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