Tool/software:
AM263x Team,
Customer is noticing a significant error margin between the actual and expected ADC readings when using the software trigger. I've attached a file containing the observations along with the ADC configuration details for Group 1, Channel 3 from customer.
More background here:
Our customer had previously asked if HW Triggered ADCs are indeed supported on AM263 (also within context of MCAL) which our reply was:
...on this (hardware triggered ADC) are that this should absolutely be supported on your AM263x even within the context of the MCAL/AUTOSAR (if needed).
Here’s why. In this AM263x MCAL ADC Guide, it explicitly lists HW trigger as supported, even under AUTOSAR:
4.1.5.2. Features Supported and Not Supported
Autosar Features Supported
Hardware triggered one-shot conversion where the converted group consists of exactly one channel.
Hardware triggered one-shot conversion where the converted group consists of more than one channel.
4.1. ADC — Platform MCAL Development - AM263 User Guide
Furthermore, it goes on to describe ADC_Hardware_Trigger configuration and setup for a given (MCAL) project.
But first, a simpler question … have you explicitly enabled the ADC Hardware Trigger?
Adc_EnableHardwareTrigger
4.1.8.2. API’s with Service ID
|
Service ID |
Autosar API’s Supported |
|
0x05 |
Adc_EnableHardwareTrigger |
If you are following this closely, I believe HW Trigger should operate as expected.
|
Document Title |
User Guide of MCAL ADC Driver |
|
Release Version |
MCAL_AM263_09.00.00 |
|
Document Version |
Version 1.4 |
|
Company |
Texas Instruments |
|
Document Name |
ADC User Guide |
Next, our Applications team confirmed that the ADC does indeed support HW trigger as we suspected.
There are some test cases for ADC HW Trigger in the MCAL package (as we mentioned below also) and these test cases are passing and qualified.
So it may be best, now, to bring this to the TI E2E Forums so we can cast a broader net for support. I apologize that this has dragged on for a few days and appreciate your patience.
One thing that was mentioned that might be an issue on your side and taking a closer look at is: "External GPIO hardware trigger is required to start conversion. Trigger can be produced by shorting GPIO pins, 80 and 82 on HSEC board."
[This is required for Hardware trigger]
Alongside the earlier SW comment of whether or not the ADC Hardware Trigger is actually ENABLED?...
Now, customer is noticing a significant error margin between the actual and expected ADC readings when using the software trigger. I've attached a file containing the observations along with the ADC configuration details for Group 1, Channel 3.
Let us know your thoughts please !
TY,
CY
