EVSPIN32G4 current sensing with 3-shunt

[kaiman]

Hello.

I am creating a motor control project for the EVSPIN32G4 using MotorControl Workbench 6.4.1.
The EVSPIN32G4 board definition provides configurations for "ThreeShunt_RawCurrents_SingleEnded_ExternalGain" and "ThreeShunt_RawCurrents_SingleEnded_InternalGain," but the current sensing section in the circuit diagram of this board appears to match the "ThreeShunt_RawCurrents_Differential_ExternalGain" configuration.

However, adding this configuration causes MotorControl Workbench to fail with an error. This is likely because the definition for "ThreeShunt_RawCurrents_Differential_ExternalGain" does not exist for the STSPIN32G4 in "MC_SDK_6.4.1\Utilities\PC_Software\STMCWB\assets\ConnectionParameters.json".

1. Why is it that the EVSPIN32G4 schematic shows a differential configuration, but the board definition only provides a single-ended option?

2. Is it possible to edit "ConnectionParameters.json" and add the "ThreeShunt_RawCurrents_Differential_ExternalGain" definition to use this configuration in MotorControl Workbench?

Thanks in advance and best regards.

[GMA]

Hello @kaiman,

The best solution for your use case could be to use the ThreeShunt_RawCurrents_Differential_ExternalGain_FilteredADCInput hardware variant. 
Each ADC input is low-pass filtered and this allows to use the HSO sensor less algorithm (refer to "HSO Startup Guide" available through "Workbench tool">About>Documentations>Documentation).

Non-HSO sensor less algorithm does not support the ThreeShunt_RawCurrents_Differential_ExternalGain hardware variant.

[kaiman]

To adopt the ThreeShunt_RawCurrents_Differential_ExternalGain_FilteredADCInput configuration, the following 4 pins are required per phase:
・CURRENT_SHUNT_*P
・CURRENT_SHUNT_*N
・CURRENT_AMPL_*
・CURRENT_FILT_*
However, since there are few available pins and the filter circuit is not implemented on the EVSPIN32G4 board, and adding a new circuit is difficult, we believe this configuration is not feasible.

To be honest, I believe any configuration is acceptable as long as there are no problems with motor control on the EVSPIN32G4 board.
Currently, the most promising configuration is the ThreeShunt_RawCurrents_SingleEnded_ExternalGain configuration, which is defined by default in EVSPIN32G4.json. Would it be alright to adopt this configuration?

[GMA · Accepted solution]

Hello @kaiman,

For the ThreeShunt_RawCurrents_Differential_ExternalGain_FilteredADCInput configuration, the statement is correct. For more details, refer to the board description wiki page available here. 
ThreeShunt_RawCurrents_SingleEnded_(InternalGain/ExternalGain) is the default three-shunt configuration used on the EVSPIN32G4 board.