Cheer X1 Protocol / SPI Capture

I did a capture of the bind sequence of the Cheer X1 TX and I need someone to verify if it is a viable capture.

The chip is a LT8901 SSOP16 (Possibly the NRF24L01 family, I don't know for sure) I found a data sheet so I think I got the MOSI, MISO, CLOCK and ENABLE connections without any issues.

Here's a zip file of the SPI Capture and the exported CSV in HEX.
http://www.mediafire.com/download/2x7utak34kiu73v/Cheer_X1_Bind_Capture.zip

Can someone verify this capture?

Thank you,

I thought I'd bump this to the top in case someone was now available to look at my capture to verify if it was a good capture or not. It's been a while and I know people are busy. Please take a moment so I can continue captures.

Thanks!

It seems that LT8901 is a simplified version of LT8900. There is a thread about LT8900 emulation - www.deviationtx.com/forum/protocol-devel.../5426-lt8900-support . As soon as it's available, it would make sense to analyze this protocol. I have a decoder for LT8900, so I'll take a look at your capture later.

Thank you for your reply!

I'll wait patiently.

I took a look. There are many unknown registers, but the trace seems to be valid, I just don't have full datasheet.

From what I decoded I can tell that it uses 62.5kbps data rate, unsupported by nRF24. So, no easy way out.

Also, CVS export like this does not make much sense, fortunately you attached original data. Sensible output is already decoded by SPI decoder - you need to assign the signals appropriately. The most frequently changing signal is CLOCK, the least - CS, or ENABLE in Saleae parlance. The rest are MISO and MOSI - most diverse is MOSI, MCU sends data and commands to RF chip through it. Least diverse is MISO, RF chip reports status back to MCU. Exception is two way communication - telemetry, but these simple models don't have it as a rule.

Victzh, strangely I can't open this capture with Saleae Logic 1.1.15 . There are no messages just nothing opens... Which version are you running?
- Pascal

Latest beta - I have high density display and 1.1.15 works incorrectly on it. And yes, it silently just did not open this file before I upgraded.

Hello all,

Thanks for looking at this. Just wanted to pass on that the captures were done with Saleae Logic 1.2.5 Beta version. I was having trouble getting 1.1.15 (64 bit) to work I recall.

CH0 MOSI
CH1 MISO
CH2 Clock
CH3 Enable
They all appear to be what you had described that I should see. Please let me know if it does not appear to be correct.

I have posted other capture sequences if you want to look.
Cheer X1 Folder

CSV file was mentioned, is it not exporting correctly or just no use to you?

Thank you,

Logicdata file is OK. CSV you exported is no use for me personally, some people may have different scripts, and for some cases it makes sense. I use SPI decoder and it's export of already decoded SPI in the CSV format. CSV means "Comma Separated Values" and is a generic format which can contain any kind of data.