- Problem
If I take statistics over the ADC results (connected to a fixed voltage; only noise) I get nearly pure even results.
I get less than 1/1000 of odd conversion results. When measuring under noisy conditions, I expect an equal distribution of even and odd values.
Are the registers initialized correctly(I attach screenshots)? Is there another pitfall in the initialisation sequence?
- Configuration
Controller XMC4400 F100K512 AB
ADC is triggered by CCU8 every 10 µs
All 4 ADCs are triggered synchronously (group 0 as master) and are configured to take Ch0 and Ch1
My code is based on the example Dave4_VADC-XMC4000-AP32305_Example_Code Example 6 "06_VADC_Synchronous_Conversions_Queue_Source"
I consider this example to be faulty since it starts the ADC before configuring the link between the groups in the Synchronization Control Register
while the documentation states: "Set the master’s GxARBCFG.ANONC at the end of the initialization."
- Unfortunately it is not possible to search the forum for "vadc":
Result is: "The following words are either very common, too long, or too short and were not included in your search: 'vadc'"
So I am not sure if the problem was answered before.
Thank you,
Ulrich.
If I take statistics over the ADC results (connected to a fixed voltage; only noise) I get nearly pure even results.
I get less than 1/1000 of odd conversion results. When measuring under noisy conditions, I expect an equal distribution of even and odd values.
Are the registers initialized correctly(I attach screenshots)? Is there another pitfall in the initialisation sequence?
- Configuration
Controller XMC4400 F100K512 AB
ADC is triggered by CCU8 every 10 µs
All 4 ADCs are triggered synchronously (group 0 as master) and are configured to take Ch0 and Ch1
My code is based on the example Dave4_VADC-XMC4000-AP32305_Example_Code Example 6 "06_VADC_Synchronous_Conversions_Queue_Source"
I consider this example to be faulty since it starts the ADC before configuring the link between the groups in the Synchronization Control Register
while the documentation states: "Set the master’s GxARBCFG.ANONC at the end of the initialization."
- Unfortunately it is not possible to search the forum for "vadc":
Result is: "The following words are either very common, too long, or too short and were not included in your search: 'vadc'"
So I am not sure if the problem was answered before.
Thank you,
Ulrich.
1 Reply
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Employee
Hi,
You might want to reference the attached software for XMC4500 which you can reuse the source file VADC.C ... etc for XMC4400.
Beside this, adding a capacitor like below might help.
You might want to reference the attached software for XMC4500 which you can reuse the source file VADC.C ... etc for XMC4400.
Beside this, adding a capacitor like below might help.