- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Hello,
Software package: PSoC Creator 2.0
Hardware: CYBC55 Board
Schamatic design: a single ADC SAR component + an analog multiplexer component + multi-analog Pins.
The voltage value acquired from the ADC SAR is correct (Acquired voltage value = real world analog input voltage) when this design works on single analog input. However, the voltage values acquired from the ADC SAR are wrong (Acquired voltage values != real world analog input voltages) when work on multi-channel inputs.
Could you please advise me how to sort out this problem.
Many thanks
Qingshan
Solved! Go to Solution.
- Labels:
-
PSoC 5LP
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
There are some pitfalls possible.
one usual is:
After switching the input-mux you'll have to discart one measurement when running in countinuos mode.
best would be to upload your project here to let us have a look at and see if everything is o.k
To do so:
Build -> Clean Project
File -> Create workspace bundle(minimal)
and then upload the resulting zip-archive here.
Bob
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
There are some pitfalls possible.
one usual is:
After switching the input-mux you'll have to discart one measurement when running in countinuos mode.
best would be to upload your project here to let us have a look at and see if everything is o.k
To do so:
Build -> Clean Project
File -> Create workspace bundle(minimal)
and then upload the resulting zip-archive here.
Bob
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Hi,
Don't use "Continuous" mode of conversion when you are muxing the input of ADC. Use "Multi-Sample" mode of conversion if resolution <= 16 bits or "Multi-Sample Turbo" if resolution > 16 bits.
Regards,
Kishore.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Kiku, there are no modes (except free-runnung and triggered) for the SAR-ADC. because it doesn't use a filter.
I'm still awaiting the project uploaded here to have a look at.
To do something right is one way, do perform something wrong, there are several ways 😉
Bob
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
Hi qingshanshan,
Are you using Triggered or free running mode?
If you are using multiple channels, then you need to use triggered mode.
The problem you will face if you use free running mode is after reading a converted value, a stray conversion would have started before and issuing a StopConvert( ) API. This will result in cross talk between two channels and hence result in corrupted values.
Using trigger mode on the other hand will allow only one conversion upon request, thereby avoiding cross talk between two channels.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content