usb-c / stusb4500 Goto Github PK

I’m trying to design a very simple Power Delivery board based on an ATtiny processor that will display a list of the source power profiles, let you select one, and then deliver it to the output.

I have one question I'm stuck on. By default, when you connect the STUSB4500 to a USB PD source it selects the highest available voltage and enables the VBUS_EN_SNK line to deliver it to the output. In my application this isn’t ideal, because it could briefly deliver a higher voltage than wanted to an external circuit, before the I2C interface to the STUSB4500 has time to reset it.

I've tried setting DPM_PDO_NUMB to 0 and doing a soft reset, but this causes an error condition.

The only solutions I can think of are:

• Drive the gate of the output MOSFET from a microcontroller I/O line, rather than VBUS_EN_SNK, so I can control when the power is enabled. However, I would have to redesign the PCBs I’ve created.

• Reprogram the STUSB4500 NVM, but I’m reluctant to have to do this.

Is there a simpler solution I’m overlooking?

Can you add this document to this repo?
tnxxx-stusb4500-nvm-description.pdf

There may be an error with some definitions in USB_PD_defines.h

The comment does not seem to match the values defined...

Line 25: /*"000" then No Operation
Line 26: "001" then Read
...
Line 35: #define READ 0x00 //Read memory array

Elsewhere in the project: "READ" is used, resulting in an always-zero bitwise...

void CUST_ReadSector(uint8_t Port,char SectorNum, unsigned char *SectorData) { ...
Buffer[0]= (READ & FTP_CUST_OPCODE);

Is this intentional?

I am trying to adapt our STM32 MCU code to read and write to the NVM registers so that the settings are saved persistently.

When I go to use nvm_flash(), the program hangs. Given that your main doesn't use any of the NVM code, is it actually tested and working? Generally, when I see this with other companies, it usually means code is incomplete and non functional.

Can you provide a simple example of it working from main?

Thanks