HDMI into HDMI+VGA+analog audio out converter

# 1. Introduction
function: Input one HDMI signal and output one HDMI signal + VGA + audio signal **_simultaneously_**.
Applications: HDMI split screen, HDMI audio splitter, video conferencing, multimedia teaching, shopping mall display, large screen monitoring, set-top box distribution, etc.
Principle: Use MS9332 for HDMI 1 input and 2 output, MS8005 for control, output one HDMI channel, and output the other channel to the CS5213 HDMI to VGA+ audio chip output.
In fact, it is also possible to use HDMI one input and two output. It only requires MS9332+MS8005 and does not require a VGA conversion IC.
![1.jpg] ![1668991492186.jpg] # 2.Some problems with
CS5213 There is a problem when using CS5213, that is, the audio output will only be available after the VGA is inserted. There will be no audio without the VGA inserted. If you want HDMI audio separation is troublesome.
My solution is to use a VGA dummy load and connect a 75~200 ohm resistor to the output VGA R signal. The CS5213 will think that you are connected to a VGA device and the audio will be output. In fact, it is connected to a dummy load. load.
When you need to use VGA, there is a travel switch in front of the VGA. Insert and detect the external VGA. The R of the VGA will be disconnected from the connected dummy load and connected to the VGA socket.
![image.png] When the travel switch is not inserted, the R pin connected to the CS5213 will be driven from the relay to the dummy load 100 ohms, causing the CS5213 to shift and insert the VGA to output audio signals.
When the VGA is about to be inserted, the travel switch is turned on to the bottom, turning on Q3, causing the relay to close the R pin of CS5213 to the R pin on the VGA seat, allowing the VGA to be used normally.
# 3. Purchase MS9332+MS8005
MS9332 is controlled by IIC, but I couldn’t get the register manual of MS9332 by searching all over the Internet. However, there are ICs matching MS8005 for sale on Ma Yun.com, so I can use the ready-made ones without programming.
Purchase link:
[https://item.taobao.com/item.htm?spm=a230r.1.14.3.2dc77778up9WD3&id=639001282691&ns=1&abbucket=10#detail](https://item.taobao.com/item.htm? spm=a230r.1.14.3.2dc77778up9WD3&id=639001282691&ns=1&abbucket=10#detail)
![image.png] # 4. Summarize
the relatively simple project, pure hardware, more practical, can be used with the HDMI 5 cut 1, 3 cut 1
Improvement:
1. HDMI performs 100 ohm impedance matching and adopts differential
2. The limit switch is currently placed directly below the VGA seat, which may cause interference when inserting the VGA. It is recommended to move it below the locking screw column on the left or right side
! [IMG_20221117_235245.jpg] 3. The MS9332 chip generates high heat under dual loads. It is recommended to add a heat sink to the chip, as does CS5213
! [IMG_20221118_120716.jpg]