@ Gene @ Dave McLaughlin
I’ve got a Cerberus and I’ve been re-reading some of the things you guys said trying to figure out exactly what I’ll be doing once I get my professor to order other parts.
I’ve changed my choice in pressure transducer since I last posted because the details of this one make it seem like it could be exposed directly to sea-water and it would be fine. I hope that’s right.
I have also been looking at the pin layout for the Cerberus board here, https://www.ghielectronics.com/uploads/doc/item/1556_large.jpg
It looks like if I hook up a ribbon cable to either socket 2, 3 and use a breakout board to expose 4 pins 3, 4 or 5 I could hook up a pressure transducer.
Gene said in a previous post that the maximum voltage my ADC (the Cerberus) can handle is the Vref. I read in the information to do with the Cerberus that the Cerberus is only supposed to be fed 3.3 V and is 5 V tolerant on all pins except the DAC pins.
Is Vref for the ADC in the Cerberus 3.3 V?
Of the two styles of output for the Dwyer Pressure transducer linked, which would be more convenient to hook up to the Cerberus? (Voltage out or current out)
Could I use the +5V (pin 1) and GND (pin 10) from an available socket to power the pressure transducer?
4 and 5. If I can power the pressure transducer with the Cerberus board, the specification sheet says the output is 0.5 V to 4.5 V. Wouldn’t that be bad since the ADC pin is only supposed to get 3.3 V and is only 5 V tolerant? Could I just drop a resistor in series with it to alleviate some of the voltage?
- It’s been mentioned by Gene that 4 to 20 mA style Pressure Transducer outputs 4 mA at zero PSI and 20 mA at max PSI regardless of the actual excitation voltage to the pressure transducer (so long as the excitation voltage falls within the prescribed window.) Do I understand this correctly?
For example: zero PSI with 9 V excitation would read 4 mA. zero PSI with 30 V excitation would read 4 mA.