Thomas Stibor replied to the topic 'Zwo vs QHY' in the forum. 3 years ago

Yes it is a firmware issue and not hardware issue. The so compatibility firmware just makes sure that the max packetsize follow the USB 2 specification and is 512 rather than 1024 bytes.
However, the issues are still remain. Switching to 8 Bit helps but there are also randomly issues (and it is for sure not the cable).
In 16 Bit mode it is like tossing a biased coin, towards not working.


./zwo_FWTool_USB2 -i ../../../firmware/USB2.0/ASI130MM.iic -t li2c
[36233.666737] usb 1-1.2: new high-speed USB device number 8 using ehci-pci
[36233.919714] usb 1-1.2: config 1 interface 0 altsetting 0 bulk endpoint 0x82 has invalid maxpacket 1024
[36233.921050] usb 1-1.2: New USB device found, idVendor=03c3, idProduct=130a, bcdDevice= 0.00
[36233.921054] usb 1-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[36233.921056] usb 1-1.2: Product: ASI130MM
[36233.921058] usb 1-1.2: Manufacturer: ZWOptical company
[36233.921060] usb 1-1.2: SerialNumber: 00000

./zwo_FWTool_USB2 -i ../../../firmware/USB2.0/ASI130MM-compatible.iic -t li2c
[36214.974532] usb 1-1.2: new high-speed USB device number 6 using ehci-pci
[36215.188389] usb 1-1.2: New USB device found, idVendor=03c3, idProduct=130a, bcdDevice= 0.00
[36215.188393] usb 1-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[36215.188395] usb 1-1.2: Product: ASI130MM
[36215.188397] usb 1-1.2: Manufacturer: ZWOptical company
[36215.188398] usb 1-1.2: SerialNumber: 00000

The binary diff between the two firmwares is:

$ cmp -l ASI130MM-compatible.iic ASI130MM.iic | awk '{printf "%08X %02X %02X\n", $1, strtonum(0$2), strtonum(0$3)}'
000001FA 02 04
000002A6 02 04
0000031A 02 04
0000038C 02 04
00000958 02 04
00000B48 02 04

One can for fun, change the "02" to "01", then the USB kernel layer complains:
config 1 interface 0 altsetting 0 bulk endpoint 0x82 has invalid maxpacket 256

Anyhow, it is still a shame, that ZWO is not able to fix the firmware. At least they could release the code and somebody would for
sure fix it for them. Just search on github.com for ASI120mm, you will find some projects reverse engineered the SDK library.

I am wondering how many INDI users had to sell (stop using) there 120/130mm cameras.
I bought a used Starlight Xpress guider and did not regret it. 130mm was my only and last ZWO product.

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