[Info] NX Mount Protocol Summary

This post is quick summary of NX mount protocol. About 4 years ago, I spent several months to figure out how NX body and lens communicate, and I quite close to working version of AF adapter. You can take a look youtube video clip how my work worked OK to communicate with NX body in below post.

http://www.mydiyworld.net/?p=695

Since the time, it was on hold and I have been working for DIY NX macro extension tube set project.

I posted all deatil what I figured out in my blog as below. But, unfortunately they are written in Korean. Google can translate some of them, but some posts included images.

http://www.mydiyworld.net/?cat=108

For anyone who is interested in knowing how NX mount protocal looks like, I will give you some information as good start for your interest.

This research has been made with NX10 which is quite old body. For sure, NX protocol must have become much complecated and faster.

Basic Protocol

NX protocol is based on SPI (Serial Peripheral Interface) communication. NX body is set as Master and Lens is set as Slave.

Basic Pin Out

Pin 1: SPI Clock - Body (Master) generates clock signal to syncronize SPI communition. (Normal High)
Pin 2: SPI MOSI - (Master Out Slave In) Body sends data to Lens. (Normal Low)
Pin 3: SPI MISO - (Master In Slave Out) Lens sends data to Body. (Normal High)
Pin 4: AF Tick - This line is used only when AF is performed. This tick commands lens report the lens status (AF location, moving status, etc). (Normal High)
Pin 5: Lens Data Ready - (Normal High) Lens set this line LOW when lens has data ready to send Body. Once this signal set LOW by lens, body will generate SPI Clock, and Lens will transfer prepared data with the clock signal.
Pin 6: GND. 0V
Pin 7: Power (3.3V) It is a powersource for microcontroller in Lens.
Pin 8: Power (5.0V) It is a powersource for motors in Lens (AF and Aperture motor)

That is about it for today. I am not an EE expert and it is far from my major in colledge, though.

If you are interested, I will post further information about NX protocol.

Thank you,
ILHYOUNG.

Thank you very much for great work, I am an EE and would greatly appreciate further information, as I'm sure would many others as well.

ihkim wrote:

This post is quick summary of NX mount protocol. About 4 years ago, I spent several months to figure out how NX body and lens communicate, and I quite close to working version of AF adapter. You can take a look youtube video clip how my work worked OK to communicate with NX body in below post.

http://www.mydiyworld.net/?p=695

Since the time, it was on hold and I have been working for DIY NX macro extension tube set project.

I posted all deatil what I figured out in my blog as below. But, unfortunately they are written in Korean. Google can translate some of them, but some posts included images.

http://www.mydiyworld.net/?cat=108

For anyone who is interested in knowing how NX mount protocal looks like, I will give you some information as good start for your interest.

This research has been made with NX10 which is quite old body. For sure, NX protocol must have become much complecated and faster.

Basic Protocol

NX protocol is based on SPI (Serial Peripheral Interface) communication. NX body is set as Master and Lens is set as Slave.

Basic Pin Out

Pin 1: SPI Clock - Body (Master) generates clock signal to syncronize SPI communition. (Normal High)
Pin 2: SPI MOSI - (Master Out Slave In) Body sends data to Lens. (Normal Low)
Pin 3: SPI MISO - (Master In Slave Out) Lens sends data to Body. (Normal High)
Pin 4: AF Tick - This line is used only when AF is performed. This tick commands lens report the lens status (AF location, moving status, etc). (Normal High)
Pin 5: Lens Data Ready - (Normal High) Lens set this line LOW when lens has data ready to send Body. Once this signal set LOW by lens, body will generate SPI Clock, and Lens will transfer prepared data with the clock signal.
Pin 6: GND. 0V
Pin 7: Power (3.3V) It is a powersource for microcontroller in Lens.
Pin 8: Power (5.0V) It is a powersource for motors in Lens (AF and Aperture motor)

That is about it for today. I am not an EE expert and it is far from my major in colledge, though.

If you are interested, I will post further information about NX protocol.

Thank you,
ILHYOUNG.

Hi Ilhyoung,

I´m definitely interested in the work you have done, impressive to say the least.

From your website it seems that you have sorted out the communication protocol between Body and lens, or do you think there still is pieces that is unknown?

For me the "dream" output from your effort and from those who have reengineered the canon EF mount would be a lens converter to be able to use EF lenses on an NX body.

The flange distance for NX is 25.5 and EF 44 mm so there should be room for some electronics to do the conversion. The Sigma SA mount also uses the EF lens protocol and has 44mm as flange distance, but it uses a version of the Pentax K-Bayonet.

A converter between NX and EF would solve the limited lens amount problem for NX system..

I recently built myself a 3dprinter and have also some experience in PCB Cad (on hobby level..) but i dont have the programming skills to pull such a project through.... however if you need anything printed or some electronics done I would be glad to help out.

Keep up the good work!

Regards

Mats

Here is a good starting point: https://pickandplace.wordpress.com/2011/10/05/canon-ef-s-protocol-and-electronic-follow-focus/

The initial problem would be providing a required voltage, could be done with DC DC boost but would better served by external battery (at least for AF). Also, there are already AF adapters for Sony E mount but they work as slow as manual focus (pretty certain that I can focus faster) as they have to rack near to far and back.

I would be satisfied by aperture control and IS on long zooms. It could probably be done independently from camera leaving the adapter purely mechanical and zero chance of damaging the camera. Then again, where is the fun in that

otto k wrote:

Also, there are already AF adapters for Sony E mount but they work as slow as manual focus (pretty certain that I can focus faster) as they have to rack near to far and back.

I believe that this should be clarified - it is an issue with the motor built into the lens, not the adapters. DSLR lenses typically don't have motors which are optimized for back and forth racking. That's the reason why some independent manufacturers refuse to put mirrorless system mounts on their lenses.

AFAIK, mentioned adapters use contrast detect for AF so no benefit of phase detection on sensor (that's the reason for full rack if I'm not mistaken) and as you said they were not made for such use (just see the performance of typical DSLR in live view). Even Sony A mount adapter for E mount does not use on sensor pdaf but phase detection sensor in adapter.

Definitely very interesting for me. Those extension tubes are awesome, were you selling any? If so, do you have any left? I finally have a start date for my job. What equipment do you use for taking measurements from the pins? Also, have you tried correlating your findings with some of the available code?

Being a software engineer, this topic caught my curiosity towards how far I could get with continuing reverse engineering the NX lens mount protocol. Being only a basic amateur at electrical engineering, the many posts around your findings were VERY helpful, from pin out description and identified patterns in the protocol. Of course, having to relay on Google translate didn't help

I have only started a few weeks ago, taking a little bit of time out from my weekends. Mostly capturing data from a used NX1000 and damaged but functional NX lens, but also occasionally staring at the data passed back and forth from the camera and lens.

My intentions is first to control the lens aperture (without camera body). After that, emulate a lens to the camera body (without physical lens attached). Then finally get to the real goal, translate the Samsung NX aperture control to Canon EF aperture control. I really don't know if I'll be able to make it that far but even if I don't, I wanted to share my findings as I progressed.

At the moment, I just have everything in text files and Saleae Logic data captures/exports, which can be viewed at http://1drv.ms/1MDK2qo Enjoy.

If/when I reach any major milestones, I'll be sure to update my progress here.

Wow, that would be a leap fwd for nx users.

DanStory wrote:

Being a software engineer, this topic caught my curiosity towards how far I could get with continuing reverse engineering the NX lens mount protocol. Being only a basic amateur at electrical engineering, the many posts around your findings were VERY helpful, from pin out description and identified patterns in the protocol. Of course, having to relay on Google translate didn't help

I have only started a few weeks ago, taking a little bit of time out from my weekends. Mostly capturing data from a used NX1000 and damaged but functional NX lens, but also occasionally staring at the data passed back and forth from the camera and lens.

My intentions is first to control the lens aperture (without camera body). After that, emulate a lens to the camera body (without physical lens attached). Then finally get to the real goal, translate the Samsung NX aperture control to Canon EF aperture control. I really don't know if I'll be able to make it that far but even if I don't, I wanted to share my findings as I progressed.

At the moment, I just have everything in text files and Saleae Logic data captures/exports, which can be viewed at http://1drv.ms/1MDK2qo Enjoy.

If/when I reach any major milestones, I'll be sure to update my progress here.

That is really awesome! Keep on going!

Aperture control and IS with Canon lenses... that would be huge!