Introduction

This is a simple tool for sending and receiving USB-PD VDM messages using a FUSB302, based on usb-c-arduino.

USB-PD VDM documentation is here

Wiring

Bare FUSB

You can use a breakout board or a bare FUSB302. You need to wire it as follows:

• 1 CC2 → Type-C CC2 (B5) - ONLY wire this to a Type-C socket used with a cable. Otherwise leave open.
• 2 VBUS → Arduino D4, Type-C VBUS (A4/A9/B4/B9)
• 3 VDD → Arduino 3V3
• 4 VDD ↑
• 5 INT_N → Arduino D12
• 6 SCL → Arduino A5
• 7 SDA → Arduino A4
• 8 GND → Arduino GND, Type-C GND (A1/A12/B1/B12)
• 9 GND ↑
• 10 CC1 → Type-C CC1 (A5)
• 11 CC1 ↑
• 12 VCONN output - leave open
• 13 VCONN output - leave open
• 14 CC2 - See pin 1 ↑

You can get away without decoupling and with only connecting one of the duplicated pins. The exposed pad is NC.

Reclaimer Labs Board

Alternatively, you can also use the Relaimer Labs board.

• 1 VBUS → Arduino D4
• 2 VPU → Arduino 3V3
• 3 VDD → Arduino 3V3
• 4 GND → Arduino GND
• 5 INT_N → Arduino D12
• 6 SCL → Arduino A5
• 7 SDA → Arduino A4
• 8 GND → Arduino GND

Cabling

Not all USB-C Cables are alike. For this you will need a SuperSpeed or Thunderbolt cable. These may or may not be marked as such. (White Apple cables don't work for example). If you get no output from a vdm command but output otherwise looks ok: try another cable.

Interface

By default the code will perform trivial (mostly hardcoded) USB-PD negotiation, then request to mux the debug UART over SBU1/SBU2. You can send custom VDMs using the Arduino serial terminal at 500000 baud.

Sample DFP mode session:

VBUS OFF
Device ID: 0x91
Init
STATUS0: 0x0
VBUS OFF
Disconnected
S: DISCONNECTED
Poll: cc1=0 cc2=0
Poll: cc1=2 cc2=0
Connected: cc1=2 cc2=0
Polarity: CC1 (normal)
VBUS ON
S: DFP_VBUS_ON
IRQ: VBUSOK (VBUS=ON)
>SOURCE_CAP
S: DFP_CONNECTED
IRQ: HARDRESET
VBUS OFF
Disconnected
S: DISCONNECTED
Poll: cc1=2 cc2=0
Connected: cc1=2 cc2=0
Polarity: CC1 (normal)
VBUS ON
S: DFP_VBUS_ON
IRQ: VBUSOK (VBUS=ON)
>SOURCE_CAP
S: DFP_CONNECTED
<REQUEST: 12000000
>ACCEPT
>PS_RDY
S: IDLE
<GET_SINK_CAP
>SINK_CAP
S: READY
>VDM SET ACTION serial -> SBU1/2
S: IDLE
<VDM RX SOP"DEBUG (5) [504F] 5AC8052 44740000 306 0 0

Sample UFP mode session:

VBUS OFF
Device ID: 0x91
Init
STATUS0: 0x0
Disconnected
IRQ: VBUSOK (VBUS=OFF)
S: DISCONNECTED
S: DISCONNECTED
IRQ: VBUSOK (VBUS=ON)
Connected: cc1=7 cc2=0
Polarity: CC1 (normal)
S: CONNECTED
<SOURCE_CAP: 3F01912C
>REQUEST
<ACCEPT
<PS_RDY
<SOURCE_CAP: 3E019096
>REQUEST
<ACCEPT
<PS_RDY
<GET_SINK_CAP
>SINK_CAP
<VDM DISCOVER_IDENTITY
>VDM DISCOVER_IDENTITY
S: READY
>VDM SET ACTION serial -> SBU1/2
S: IDLE
  input: "5AC8010\n"
>VDM 5AC8010
<VDM RX SOP'DEBUG (7) [724F] 5AC8050 46060606 2060301 3060106 1050303 8030809 1030000
  input: "5AC8011,306\n"
>VDM 5AC8011 306
<VDM RX SOP'DEBUG (3) [344F] 5AC8051 187020C 800C0000
  input: "5AC8012,1840306\n"
>VDM 5AC8012 1840306
<VDM RX SOP'DEBUG (5) [504F] 5AC8052 44740000 306 0 0