STEVAL-PTOOL2V1, STSPIN32F0252, the current cannot be read below 1A

[eric239955_stm1]

For example current detection, 

HW:STEVAL-PTOOL2V1

SW:en.stsw-ptool2v1_v1.0.0.zip

It will be abnormal when it is about 4A or below, and it cannot read below 1A.

About 4A or more (to more than 10A) can be detected normally,

Could you please help me where may have problems.

Thank you.

[Cristiana SCARAMEL · Accepted solution]

Hello @Community member​,

first of all what kind of driving method do you want to use?

The board has a single shunt sensing topology; it support Field-oriented control (FOC) and sensored or sensorless 6-step control.

The STSW-PTOOL2V1 firmware implements a voltage mode control with Hall effect sensor feedback that is the default hardware configuration also for the STEVAL-PTOOL2V1 board.

So in this case the current feedback it is not used by the FW.

Anyway, the board is designed to manage high currents (the over-current protection is set by default at 36 A). If you want to manage "low current" you have to resize the amplifier network of U2A.

With the default value you have: Vsense = 3 mOhm x 1 A = 3 mV

The amplifier network is x18 --> current feedback is around 50 mV that is a small value.

Let me know if these info are useful to you, if yes please "Select as Best" label.

[eric239955_stm1]

Sensorless 6-step control.

Thank you very much for your assistance. I will try.