Missing protocol/SDK support for Delta2c_PRO_D_V001

[poteytoman]

Hi everyone,
I'm working on an autonomous robotics project and I'm using the Delta2C-PRO_D_V001 model.
I noticed that this specific "Pro" model is missing from the supported series. I have been analyzing the serial output, and I am consistently receiving a steady stream of data, but I cannot seem to trigger the measurement data stream.
aa 00 09 11 61 ae 00 01 fa 02 ce
The device is powered, and the motor is spinning, but the distance/angle values in the packets remain constant. Does this model require a specific "Start" command? Any documentation would be greatly appreciated.

Thank you!

[makers-pet]

Hello,

I'm afraid I don't have a Delta-2C LiDAR or any documentation for it. I have 3irobotix Delta-2 A, B and D only.

If I find Delta 2C docs I will let you know.

[poteytoman]

Hi makerspet

Thank you very much for your response and for clarifying the situation regarding the Delta-2C model. Even though it is not officially supported in your library, your quick reply helped me focus my efforts on the correct model and troubleshoot the hardware connections properly. I truly appreciate your help and the work you do for the community. I will keep looking for the documentation, and if I manage to uncover anything useful, I will be sure to share it here.

Thanks again!

[makers-pet]

Hi poteytoman, no worries. I've run a search and there is no Delta-2C specs or code or protocol published at all (even in the official 3irobotix SDK).

That said, can you please send me sample Delta-2C serial output? I can ask my Claude Code to try reverse engineering it.

[poteytoman]

lidar.txt

Hi makerspet,

Thank you so much for the update and for your help. I apologize for the delay in responding—I missed your message earlier!

I really appreciate your offer to look into this with your AI tools. Since there is no public documentation for the Delta-2C, having another pair of eyes on the serial data would be incredibly valuable.

"I have attached a text file containing a sample of the serial output I am receiving from the device. I hope this helps in identifying the protocol or the "Start" command structure."

Please let me know if you need any additional logs, such as different power-on sequences or data captured while the motor is running. I’m happy to provide whatever you need to help figure this out.

Thanks again for your time and for supporting the community!

Best regards,

[kaiaai]

Hi poteytoman,

I've asked Claude to check your lidar.txt (thank you).

Long story short, you seem to be using the wrong baud rate. Please try recapturing data at 256000 or 250000 bps.

Otherwise, it seems your Delta-2C does use the usual Delta-2A/B/G protocol.

[poteytoman]

Hi Kaiaai,

Thank you for looking into my lidar.txt file and for the suggestions.

I have already tried recapturing the data using both 256,000 and 250,000 bps as you suggested, but unfortunately, I am still not getting any meaningful results. The data stream remains static and does not reflect any movement.

I appreciate you taking the time to help me with this. Thanks again for your support!

[makers-pet]

Is the Lidar puck spinning or stationary?

The puck should be spinning at a target RPM, probably 5 Hz.

[poteytoman]

Hi, thanks for your help. The Lidar puck is spinning and reaches a target RPM, but I'm having trouble getting consistent range data from it. I’ve decided to take a break from this for now and look at it again later with fresh eyes. Thanks again for your time!

[hapynfdj]

Hey, just wanted to give you a quick update. I finally got the DELTA2C fully reverse engineered. The protocol is completely figured out now, frame structure, byte order, sampling offsets, all of it. Turns out the correct baud rate is 115200, and the motor needs around 2.9V to work properly. Data quality is actually really good once everything is dialed in.
I'm from China by the way, and I'm 14. This project has officially kicked off and I'm planning to push everything to my repo soon. If you need access or want to take a look, just let me know and I can share it with you. Also wondering if you'd be interested in merging this into your existing codebase or keeping it as a separate thing. Let me know what you think.

[poteytoman]

Hey! Wow, this is seriously impressive work—congratulations on fully reverse engineering the DELTA2C!

We had actually been struggling with this exact topic for a while without a solution, so your breakthrough is immensely helpful to us and the community. Figuring out the frame structure, byte order, baud rate, and voltage requirements all on your own at 14 years old is amazing technical talent. Huge thanks for sharing this update!

Please share the link to your repository whenever you publish it. I’d love to take a look at the code and test it out. Regarding integration vs. keeping it separate: once you drop the link, we can check out the implementation together and see what makes the most sense (whether bringing it into the main codebase or keeping it as a dedicated package/driver).

Thanks again for your hard work and generosity in sharing it! Looking forward to your repo release.

[makers-pet]

Hi hapynfdj,

you having figured out the Delta-2C protocol sounds great! Congratulations!

Yes, I'd be interested to add Delta-2C and merge your code with your permission.

Ilia

[hapynfdj]

Hey, I’ve uploaded it to my repository. It’s functional right now, but it’s definitely still a work in progress. Probably missing some stuff, and there might be some errors I haven’t caught. I’ll keep improving it and adding stuff later. Sorry for the rough edges! Hope that works for you for now.

[hapynfdj]

哎，我感觉我根本不太说得来英文 Sorry. Performance Display / Performance Showcase

写的可能不是很好，目前测试了大概是可以用的。其实我也是刚入这个圈子，不是很知道该怎么做，只是尽我所能而已。也许每个人的激光雷达品质是不一样的，我的参数在别人那不一定能够正常使用。我是使用的可调电源进行供电 像我上面图片这两个效果，都是用的 2.6V 电压供电，电流 0.04A 花费了一个下午的时间去逆向这个协议，今天上午还要去补课学习，所以没有太多时间

[hapynfdj]

Alright bro, I’ve got two units of these lidars and they’re pretty similar. I’ve been experimenting with the supply voltage, and it looks like 2.9V isn’t very stable — you end up with fewer valid points. But at the correct baud rate of 115200, the readings stabilize considerably.
From analyzing the serial data, it seems that when the motor spins too fast, the chip can’t keep up, which results in repeated/stale readings. The motor is spinning, but the reported distance and angle values stop updating entirely — this strongly suggests the RPM has exceeded the usable range.
Based on both units (and consistent with your observations), the normal operating frequency appears to be around 7 Hz. So while this may not be my final conclusion, I’ve put quite a bit of effort into figuring this out. I’m sharing what I have so far, and I totally understand if updates are slow — I’m busy too, but I’ll keep looking at it and improving the codebase whenever I can. If you’d like to check the actual experimental data, feel free to look at my repo. Any additional pointers would be greatly appreciated!

[makers-pet]

@hapynfdj thank you very much for your contribution!

My Claude has checked your repo and merged Delta-2C code into kaiaai/LDS with one tweak. Based on Delta-2C data captured independently, the resolution likely remains 0.25mm, does not change to 0.5mm from Delta-2A.

[hapynfdj]

@makers-pet I don't have a ruler at home, so I haven't been able to measure the resolution. Sorry about that!