STUSB1602 SPI interface

[Lukasz Przenioslo]

Hello there,

I am currently analyzing the STUSB1602 chip and the P-NUCLEO-USB002 eval kit. I have come across a topic I am not fully certain about. Its the SPI interface for the BMC communication. I cannot understand either it is necessary in all applications, or only if I want to exchange some specific data between devices over CC line? For example, if I intend to create a sink only device, so I have to connect the SPI lines and provide any data from the MCU? I would appreciate all help.

[Lukasz Przenioslo]

The only logs from the STREF-SCS001V1 is the 2 leds. I see that the blue one is constantly ON, not blinking, which would mean it negotiated something (if I recall correctly the documentation). This is a peculiar one.

[Lukasz Przenioslo]

Hello Benoit,

So my adventures with the P-NUCLEO-USB002 ended after I have connected external 20 V supply to the CN12 port. The whole circuit was not powered up at that instance. I have only heard the typical "crack" of a frying IC and then came the smell... With the corner of my eye I have seen the display of the lab AC adapter, on which some current was indicated for a moment. Looking at the schematics of the P-NUCLEO-USB002 I am not sure what went wrong. The + terminal of the CN12 goes to the INA199A1DCK chip, which has 26 V differential input. Also I did not swap terminals polarity, I am certain. INA199A1DCK must have transferred the 20V input to the output since all circuit is dead (both base Nucleo board and the USB C hat).

Benoit- Any chance you have this P-NUCLEO-USB002 for spare? Also, do you have any clue what went wrong here?

[Benoit FORET]

V, ​Hello Lukasz,

I'm afraid in order to use the board with power management (over 5V I mean), it does not work this way. The port in the back of the blue board is used for that but it is quite complex to set-up. The protocol manages accurately the voltage transition (from 5V to the agreed voltage). This is why 20V can't be plugged directly. I'm going to ship to you:

- an STEVAL-ISC004V1 that you can use as a 5V, 9V, 12V, 15V, 20V SOURCE / power supply, and in order to read SINK capabilities,

- and a replacement P-NUCLEO-USB002 that I advise to use as a "sniffer" (and not as a SOURCE), in order to read attached device role and profiles.

rgds,

Benoit

[Lukasz Przenioslo]

Hello Benoit,
I understand, maybe I should study this more carefully. Thank you very much for help!

[Lukasz Przenioslo]

Hello Benoit,

I started testing the p-nucleo-usb002 with STEVAL-ISC004V1 right ahead. I was able to choose all available profiles but 5th:

P-NUCLEO-USB00x Demo v1.0.4
Console v0.4
Type help for a list of commands.
STMicroelectronics
Copyright (c) 2017 - All Rights Reserved.
>
*** [1] attached on CC2 (Sink)
 
*** [1] selected cap #1
s 1
Role: Sink - Explicit contract CC2 Profile 1 5.00V
>r 1 1
Requested 1 : 5.00V 3.00A
>
*** [1] selected cap #1
r 1 2
Requested 2 : 9.00V 3.00A
>
*** [1] selected cap #2
r 1 3
Requested 3 : 12.00V 3.00A
>
*** [1] selected cap #3
r 1 4
Requested 4 : 15.00V 3.00A
>
*** [1] selected cap #4
r 1 5
Requested 5 : 20.00V 2.25A
>
*** [1] detached
 
*** [1] attached on CC2 (Sink)
 
*** [1] selected cap #1

When I connected the STREF-SCS001V1 to the STEVAL-ISC004V1, I got 20 V output, so this one works. What could be the case for p-nucleo-usb002?

[Benoit FORET]

​Hi Lukasz,

very strange. working properly on my side. Which Power supply are you using to power STEVAL-ISC004V1 (SOURCE)? We recommend 24V DC to supply the DC/DC from the board and ensure clean 20V output. What might happen is that the DC/DC can't regulate properly at 20V, so either the SOURCE and the SINK may terminate the connection as not in line with the expected contract (20V) +/- OVLO/UVLO (usually 10% if I remember well). In this case, the 2 different SINKs may have different settings, explaining the difference.

rgds,

Benoit

[Lukasz Przenioslo]

Hi Benoit,
I was providing 23V from a lab AC adapter. Didnt try 24 V. The sink device has the default settings. The day after tommorow I will be at the office again. I will try with higher input voltage, thank you.

[Lukasz Przenioslo]

Hello Benoit,

I just tried connecting 25 V to the STEVAL-ISC004V1. I was able to successfully switch to the last profile like you now using the p-nucleo-usb002. Probably voltage drop on the DC-DC converter was to high. Thank you for help.

Btw, I wanted to test how would the p-nucleo-usb002 act after I connect a generic USB charger to it, like this: https://allegro.pl/ladowarka-gc-usb-c-45w-laptopa-acer-asus-dell-hp-i7527595704.html (frogive the polish language). Anyways, the specification says that it should support the following profiles: 5V-3A, 9V-3A, 12V-3A, 15V-3A, 20V-2.25A.

After I connected it to the p-nucleo-usb002 connector, I havent seen any event in the terminal nor on the leds- like the p-nucleo-usb002 didnt notice this charger at all. What could be the case here, since it is possible to charge a mobile phone using this USB C charger?

[Benoit FORET]

Hi Lukasz,

no reason, it should connect properly. Have you tried connecting ​the STREF-SCS001V1 to this USB charger? it should connect at 20V automatically if I cross properly the PDO from both devices.

benoit