Trying to use USB-C DP Alt mode to get USB and HDMI Outputs - Page 1
Forum section: electronics / projects

author: ZGoode
author_rank: Frequent Contributor
timestamp: December 02, 2024, 05:54:02 pm
content: I'm trying to work on an all in one solution for my Wacom tablet that uses this abomination of a USB/HDMI cable for input to be just one type-C cable. It is a gen 1 Wacom One that uses this horrible cross cable thing. From looking into different options I could use for this I stumbled upon a few different solutions that could work.1) MCDP5200 based solution. This chip allows for a USB source and HDMI source in a one dip solution. Downside is I'd have to deal with a BGA abomination2) STEVAL-USBCD2P and PS176. The STM32 communicates over the USB-C to get DP alt mode and then the PS176 converts the DP to HDMI. Downside, can't find reliable source for PS176 chips or datasheet.3) I found a 3rd option which appears to be the MAX9406. If I am reading the eval kit/datasheet right this chip can do direct DP to HDMI conversion?Is there any other methods people would recommend for this? I'm leaning towards the MCDP5200, but want to hear other inputs from people before going that route. The nice thing about that solution is I have complete schematics for this solution already and would just need to do board design. Only thing that worries me is I have never done BGA design work other than a basic 10 ball power regulator.

author: i509VCB
author_rank: Contributor
timestamp: December 05, 2024, 07:52:09 pm
content: Quote from: ZGoode on December 02, 2024, 05:54:02 pmWithout a datasheet or reference design you probably wont get very far. Iirc it's a 0.5mm BGA which also makes it even harder for prototype level cost. At least you can buy it, but the vendor in the last year just black holed their datasheets. It was possible to guess the URL to the full ones in the past but that is gone now.Quote from: ZGoode on December 02, 2024, 05:54:02 pmI'm not sure the Maxim part can do conversion. To me it looks like something you'd use if your host device supports DisplayPort++ (HDMI over displayport). The functional diagram seems to hint it's not truly doing the decode and then re-encode.

author: ZGoode
author_rank: Frequent Contributor
timestamp: December 09, 2024, 07:26:59 pm
content: I think you are right about the Maxim part. Thankfully I have not bought anything for this yet.For the Kinetic Part (MCDP5200), I have a PDF of a full schematic for the evaluation board, which pretty much does everything I need. I just don't have the board layout for that kit.For the Parade parts, which is what I would like to use, I have a grey market source for those chips, but finding information is difficult. I have a brief datasheet (for both the PS176 and PS171) that at least gives me a pinout and not much else. Since I am not looking to buy 10s of thousands Parade isn't going to want to help here unfortunately.edit: I know I probably should post the PDF's and datasheets I found here, but I also do not want to get in trouble since they are watermarked and definitely not supposed to have made their way onto the public internet. Parade would not be happy to know that they made it out onto the internet.