Andrei IRL
Senior Member
Hi everyone.
I am building a strain-gauge and the controller using PICAXE 14M2 and AD623 Instrumental Amplifier.
Everything is working as expected except for one small issue.
Every now and again PICAXE would get a random reading lower then expected without any changes to the strain gauge.
I have the System running off Bench power supply but have also tried using battery pack which resulted in the same issue.
I have tried to filter any odd readings buy running an extra routine in the program "fire check", which placed a delay of 25ms (50ms at 8Mhz) and re-checking the inut signal once more.
Only then if the signal is still less then threshold would the code move on.
However this random triggering is still happening despite trying to rule it out buy using code.
I have attached Schematic diagram as well as Screenshot of the Terminal.
Screenshot shows the moment false triggering happened when ADC reading went to 386 or so. Threashold for the trigger was set to around 500.
Reading with no load on the loadcell is around 560 the rest of the time.
So i am trying to figure out whats causing this random ADC readings and how to go about fixing it.
What i have noticed is this random triggering might happen when i turn my table light on or off at times, but id have to try for a good few minutes to make this happen.
Not sure if this would happened when ran on battery power only.
I have tried different straingauges (loadcell) wit same result.
I have an oscilloscope but its about 60 years old analog one and i have tried reading some signals using it but could detect any noise anywhere on the circuit.
Thanks very much in advance for any input on this.
I am building a strain-gauge and the controller using PICAXE 14M2 and AD623 Instrumental Amplifier.
Everything is working as expected except for one small issue.
Every now and again PICAXE would get a random reading lower then expected without any changes to the strain gauge.
I have the System running off Bench power supply but have also tried using battery pack which resulted in the same issue.
I have tried to filter any odd readings buy running an extra routine in the program "fire check", which placed a delay of 25ms (50ms at 8Mhz) and re-checking the inut signal once more.
Only then if the signal is still less then threshold would the code move on.
However this random triggering is still happening despite trying to rule it out buy using code.
I have attached Schematic diagram as well as Screenshot of the Terminal.
Screenshot shows the moment false triggering happened when ADC reading went to 386 or so. Threashold for the trigger was set to around 500.
Reading with no load on the loadcell is around 560 the rest of the time.
So i am trying to figure out whats causing this random ADC readings and how to go about fixing it.
What i have noticed is this random triggering might happen when i turn my table light on or off at times, but id have to try for a good few minutes to make this happen.
Not sure if this would happened when ran on battery power only.
I have tried different straingauges (loadcell) wit same result.
I have an oscilloscope but its about 60 years old analog one and i have tried reading some signals using it but could detect any noise anywhere on the circuit.
Thanks very much in advance for any input on this.