https://github.com/charkster/usb_pd_monitor

USB PD cc pin monitor implemented in a Tang Nano 9K FPGA.
https://github.com/charkster/usb_pd_monitor

fpga tang-nano-9k usb-pd

Last synced: about 17 hours ago
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USB PD cc pin monitor implemented in a Tang Nano 9K FPGA.

• Host: GitHub
• URL: https://github.com/charkster/usb_pd_monitor
• Owner: charkster
• License: mit
• Created: 2022-04-30T01:58:16.000Z (over 2 years ago)
• Default Branch: main
• Last Pushed: 2024-02-11T21:42:28.000Z (9 months ago)
• Last Synced: 2024-02-11T22:39:09.355Z (9 months ago)
• Topics: fpga, tang-nano-9k, usb-pd
• Language: SystemVerilog
• Homepage:
• Size: 4.41 MB
• Stars: 11
• Watchers: 4
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# usb_pd_monitor

**USB PD monitor** implemented in a **Tang Nano 9K** FPGA board. USB-PD packet data is **decoded from the CC pins** and then sent out the FPGA as **UART TX data**. The Tang Nano 9K's **USB-to-UART** bridge (software FTDI FT2232C running on the BL702 IC) can be accessed with **Python** to see the packet data.

**The only physical connections needed are CC1, CC2 and their ground pins**. The Tang Nano 9K is powered by the USB connection to the host computer. 

![picture](https://github.com/charkster/tang_nano_9k-uart_block_ram/blob/main/images/tang_nano_9k_pinout.png)

Using the **1.8V pins**, this FPGA board is able to monitor the USB-PD messages on the CC pins **without any levelshifters**.

See [fpga/src/tang_nano_9k_generic.cst](https://github.com/charkster/usb_pd_monitor/blob/main/fpga/src/tang_nano_9k_generic.cst) for pins used. **3.3V buffered CC1 and CC2 outputs are available to veiw with a logic analyzer** (I highly recommend the [$12 Saleae clones on Amazon.com](https://www.amazon.com/HiLetgo-Analyzer-Ferrite-Channel-Arduino/dp/B077LSG5P2), as sigrok pulseview has full USB PD decoding). I also have a 3.3V buffered "uart_tx_buf" signal which can connect to a logic analyzer or another serial-to-usb adapter.

Tang Nano 9k board Info:

https://wiki.sipeed.com/hardware/en/tang/Tang-Nano-9K/Nano-9K.html

I used the eLabBay USB C passthrough breakout board:

![picture](https://github.com/charkster/usb_pd_monitor/blob/main/images/usb_c_passthrough_breakout.png)

https://elabbay.myshopify.com/products/usb3-1-cm-cf-v1a-usb3-1-type-c-male-to-female-pass-through-breakout-board

Here are some captures from **Sigrok's Pulseview using my HiLetgo $12 logic analyzer**:

D0 is the buffered 3.3V version of the CC pin data. D1 is the 3.3V uart_tx_buf that the FPGA sends to the USB-to-UART bridge IC on the Tang Nano board. Pulseview is able to fully decode the 3.3V CC pin data. 

![picture](https://github.com/charkster/usb_pd_monitor/blob/main/images/usb_pd_get_source_cap1.png)

![picture](https://github.com/charkster/usb_pd_monitor/blob/main/images/usb_pd_good_crc.png)