Other Parts Discussed in Thread: ENERGIA, PGA460
We are currently developing a distance measuring system that uses ultrasonic sensors. For this purpose, we decided to use the PGA460-Q1 with the Transformer-Driven schematic, as described in its datasheet section 8.2 (Application and Implementation – Typical Applications).
Since we are going to use 10 ultrasonic transducers we inserted a multiplexer between the transformer circuit and the transducers in order to reduce the number of PGA's and transformers necessary. In this manner we could select to which transducer the PGA would send and receive signal from.
Done that, we first configured the PGA using the given example “Get-Distance”, as showed in the document “PGA460 Software Development Guide”. In our project, we use an ATmega2560 to communicate with the PGA-460. Using the Serial1 of the Atmega2560 we believe to be possible to use the libraries provided for the Energia in the “Tool & Software” section (www.ti.com/.../toolssoftware).
To test the system, we fixed an ultrasonic transducer in front of a wall, within a distance of around a meter and a half and we performed some measurements. In this first test, we weren`t using the multiplexer.
As results we, got a series of uncoherent measures, which sometimes were constant 7 meters, or sometimes 5,64 meters and other times they were apparently random.
We even tried to customize de “Get-Distance” example, so, using the multiplexer, we could get measurements for all the 10 ultrasonic sensors. Unfortunately, this method showed the same results as the previous test.
What can we do to correct our results?
