[Android Head-Units] h1p1n3:
Hey all!

I have a HIZPO head unit, labeled as the title for the model number. I have been able to root the device a while ago and got it setup best I could but there's a few things bugging me that I would like to solve. First of course is the bluetooth capabilities. As others mentioned the bluetooth doesn't work traditionally, but can be with another bluetooth adapter like mentioned here.

The other biggie is the USB connection. It appears that the devices can only access FAT32 formatted drives which is fine if you just want to load up some mp3's but I would like to get OTG to work. The information on these units in the forum are scattered with no concise answer from what I can tell.

I've connected my phone with a USB-C cable to the head unit, and the unit sees my phone. Using an app, "OTG Guru" I can see my phone and it's details which I have posted below.

ID: 0

Path: /dev/bus/usb/002/051

VID: 0x04E8 (Samsung Electronics Co., Ltd)

PID: 0x6860 (Galaxy A5 (MTP))

Class: 0 (USB_CLASS_PER_INTERFACE)

Subclass: 0

Protocol: 0

5 Interfaces:

ID: 0

Class: 6 (USB_CLASS_STILL_IMAGE)

Subclass: 1

Protocol: 1

3 Endpoints:

ID: 0

Descriptor: [0x07 0x05 0x81 0x02 0x00 0x02 0x00]

Address: 0x81

Endpoint Number: 1

Direction: 1 (device to host)

Attributes: 0b00000010

Type: 0b10 (Bulk)

Max. Packet Size: 512 Bytes

Interval: 0

ID: 1

Descriptor: [0x07 0x05 0x01 0x02 0x00 0x02 0x01]

Address: 0x01

Endpoint Number: 1

Direction: 0 (host to device)

Attributes: 0b00000010

Type: 0b10 (Bulk)

Max. Packet Size: 512 Bytes

Interval: 1

ID: 2

Descriptor: [0x07 0x05 0x82 0x03 0x1C 0x00 0x06]

Address: 0x82

Endpoint Number: 2

Direction: 1 (device to host)

Attributes: 0b00000011

Type: 0b11 (Interrupt)

Max. Packet Size: 28 Bytes

Interval: 6

ID: 1

Class: 2 (USB_CLASS_COMM)

Subclass: 2

Protocol: 1

1 Endpoint:

ID: 0

Descriptor: [0x07 0x05 0x84 0x03 0x0A 0x00 0x09]

Address: 0x84

Endpoint Number: 4

Direction: 1 (device to host)

Attributes: 0b00000011

Type: 0b11 (Interrupt)

Max. Packet Size: 10 Bytes

Interval: 9

ID: 2

Class: 10 (USB_CLASS_CDC_DATA)

Subclass: 0

Protocol: 0

2 Endpoints:

ID: 0

Descriptor: [0x07 0x05 0x83 0x02 0x00 0x02 0x00]

Address: 0x83

Endpoint Number: 3

Direction: 1 (device to host)

Attributes: 0b00000010

Type: 0b10 (Bulk)

Max. Packet Size: 512 Bytes

Interval: 0

ID: 1

Descriptor: [0x07 0x05 0x02 0x02 0x00 0x02 0x00]

Address: 0x02

Endpoint Number: 2

Direction: 0 (host to device)

Attributes: 0b00000010

Type: 0b10 (Bulk)

Max. Packet Size: 512 Bytes

Interval: 0

ID: 3

Class: 255 (USB_CLASS_VENDOR_SPEC)

Subclass: 64

Protocol: 2

2 Endpoints:

ID: 0

Descriptor: [0x07 0x05 0x85 0x02 0x00 0x02 0x00]

Address: 0x85

Endpoint Number: 5

Direction: 1 (device to host)

Attributes: 0b00000010

Type: 0b10 (Bulk)

Max. Packet Size: 512 Bytes

Interval: 0

ID: 1

Descriptor: [0x07 0x05 0x03 0x02 0x00 0x02 0x00]

Address: 0x03

Endpoint Number: 3

Direction: 0 (host to device)

Attributes: 0b00000010

Type: 0b10 (Bulk)

Max. Packet Size: 512 Bytes

Interval: 0

ID: 4

Class: 255 (USB_CLASS_VENDOR_SPEC)

Subclass: 66

Protocol: 1

2 Endpoints:

ID: 0

Descriptor: [0x07 0x05 0x04 0x02 0x00 0x02 0x00]

Address: 0x04

Endpoint Number: 4

Direction: 0 (host to device)

Attributes: 0b00000010

Type: 0b10 (Bulk)

Max. Packet Size: 512 Bytes

Interval: 0

ID: 1

Descriptor: [0x07 0x05 0x86 0x02 0x00 0x02 0x00]

Address: 0x86

Endpoint Number: 6

Direction: 1 (device to host)

Attributes: 0b00000010

Type: 0b10 (Bulk)

Max. Packet Size: 512 Bytes

Interval: 0

My knowledge is limited here, but it seems as if the device hardware wise can see the phone, and there's 5 interfaces, and each has 2 endpoints, both host to device, and device to host except for USB_CLASS_COMM which just has device to host and not host to device. I wonder if this is why we can't access the phone's storage? However this is not my goal. I tether my phone to the head unit for data, and since I use PDAnet to hide my tether usage from my isp I have to use "WIFI DIRECT" mode, which also uses a VPN, which then makes a lot of apps think the device is online since there isn't a default wifi connection. Plus it's a lot slower. I would like to do USB Tether, and of course have normal OTG and USB functionality. Has anyone made headway with this?

Lastly my main question is regarding the desire for everyone to update the firmware and OS. Are there any significant functionality benefits to upgrading? Is there additional MCU functions with the updates?

Edit: I want to add, in the system settings there are options for Bluetooth version. Has anyone played with these settings?