Hello Everyone,
I am making a data acquisition system using a raspberry pi .
Ive posted many questions on the forum and got great answers ,my project is in its final stage and i am having some problems,
Let me tell you What ive done so far,
Stage one :
POWER and SENSOR circuit:
so I have made an Instrumentation amplifier circuit to get differential data from the sensor which is some thing like this
(sensor has 5 wires +- 5V output and shielding wire is grounded to smps ground)
(Pressure sensor 2mV/V)
now the instrumentation amplifier circuit is something like this
(it also ha a low pass filter)
Sensor circuit is powered by +-5 v supply
The output of this circuit is given to adc
(ads1115 which is )
PROBLEM:Now the output of this adc is connected to raspberry pi as i have uploaded the pdf of full circuit
there seems to be some grounding problem
as The circuit is powered by smps(supply no1)
and raspberry pi by (supply no 2)
how do i connect grounds of adc and raspberry pi or smps ground
heres the pdf of my circuit . I have used arrangement for 2 sensors :
(arrangement near pin 1 and 3 is of rotary encoder +5v which works fine )
http://forum.allaboutcircuits.com/a...8/?temp_hash=51722f05aa3ae2f4f48f1becf092af95
Please review and help
Thankyou in advance !!!
I am making a data acquisition system using a raspberry pi .
Ive posted many questions on the forum and got great answers ,my project is in its final stage and i am having some problems,
Let me tell you What ive done so far,
Stage one :
POWER and SENSOR circuit:
so I have made an Instrumentation amplifier circuit to get differential data from the sensor which is some thing like this
(sensor has 5 wires +- 5V output and shielding wire is grounded to smps ground)
(Pressure sensor 2mV/V)
now the instrumentation amplifier circuit is something like this
(it also ha a low pass filter)
Sensor circuit is powered by +-5 v supply
The output of this circuit is given to adc
(ads1115 which is )
PROBLEM:Now the output of this adc is connected to raspberry pi as i have uploaded the pdf of full circuit
there seems to be some grounding problem
as The circuit is powered by smps(supply no1)
and raspberry pi by (supply no 2)
how do i connect grounds of adc and raspberry pi or smps ground
heres the pdf of my circuit . I have used arrangement for 2 sensors :
(arrangement near pin 1 and 3 is of rotary encoder +5v which works fine )
http://forum.allaboutcircuits.com/a...8/?temp_hash=51722f05aa3ae2f4f48f1becf092af95
Please review and help
Thankyou in advance !!!
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