Establishing serial interface: MIRICLE cores - Page 1
Forum section: electronics / general

author: Vipitis
author_rank: Frequent Contributor
timestamp: March 26, 2021, 08:14:01 pm
content: With this thread I am asking for help in establishing serial (RS232) communication with my thermal imaging cores. It's essentially the current roadblock I had in my project for over a year (https://www.eevblog.com/forum/thermal-imaging/thermal-camera-for-filmmaking-and-photography/).I do have some documentation for the cores including pinot and serial commands. I will later on post of excerpts of those.I explained my issue in the linked thread, but I wanted to post a threat just on this issue to give it more reach. The main problem I am having seems to be that the camera core is not recieving my commands.I wired up the serial output, serial input and 0V to the Rx TX and GND pins on my RS232 USB interface and turning the camera core on gives me the a status message from the camera of software and hardware versions. Followed by "DSP:>"If I set the baud rate to 115200 as indicated by the documentation the camera only responds with "camera baud is 9600".I strongly believe that I am recieving signals from the camera correctly as this is both expected behaviour as per documentation. Said documentation also details how the camera can receive commands via a data or via text format. And no matter what text commands I send nothing happens. There is no response and "reset" also triggers no restart of the core.I measured a connection from the input pin to the ground pin when connected to the usb interface. This is one point I am unsure about. If I connect the interface to itself, I do get the expected ping pong loopback.Open questions are: what does the DSP mean here? I suspect it might be a password or handshake that it is waiting for, but I haven't found any refence to such functionality in my documentation. The only DSP mentioned is about how the camera core can control lens Focus via commands. Which is likely what is was doing. The camera was wired up to all tree pins mentioned as well as had a motorized lens system. I even have a controller joystick with a focus knob. I will append this section of the documentation later this weekend.Options I currently have left:-try to communicate via "data" commands-try a different serial interface-get a scope and find how far the signal goesI would like to know if I am missing anything here as I haven't worked with serial interfaces before and I don't have much equipment right now to go deep. As this project has been stagnant for a long while, I am determined to progress with it, especially if that means buying new equipment like a scope that can decode serial.Vipitis

author: Vipitis
author_rank: Frequent Contributor
timestamp: March 26, 2021, 08:15:51 pm
content: I wanted to first exhaust all my options before making a thread, but as there has been lots of similar talk on the forum recently I wanted to take the opportunity and post this earlier. I hope to follow up on Sunday or Monday with some excerpts from the documentation of other questions that might come up.

author: VGN
author_rank: Regular Contributor
timestamp: March 26, 2021, 09:28:20 pm
content: Quote from: Vipitis on March 26, 2021, 08:14:01 pmQuote from: Vipitis on March 26, 2021, 08:14:01 pm1. Probably you are not properly terminating the commands. I mean CR and LF symbols at the end of the string. Try all combinations, CR only, LF only, CR+LF. This symbols could be used by camera to detect the end of the string before parcing and processing the command.2. Are you sure that there is no hardware flow control over CTS/RTS?

author: Vipitis
author_rank: Frequent Contributor
timestamp: March 26, 2021, 11:35:46 pm
content: I am attaching the serial control documentation here.As for the different CR/LF modes, I believe I tried all of them for send and receive but I will take my take to do it thoroughly again in the next few days. I know that there are several different variants of the core that allow for extra connectors to be fitted (such as USB) but mine seem to be the MIRICLE -KS OEM variants as they have been embedded in a maritime system. There is proprietary stuff in black boxes that was likely used to control these but I am hoping to just access the camera cores. Changing settings and enabling USB would allow me to get raw frames at 25 or 50 hz it seems which is what I would love to have as a starting point instead of AV.There is other documentation on USB setup and LVDS, which could be a last resort but without serial communication that is likely not even turned on.

author: Ultrapurple
author_rank: Super Contributor
timestamp: March 27, 2021, 03:52:25 pm
content: Hi VipitisI guess you have done the basics of setting the baud rate, bits, stop bits and flow control correctly? I have very little experience in this area but when I was establishing comms with my camera I had to enable Xon/Xoff. The next trick was to send to the cameraecho:on- that meant I could see what I was typing, and it gave me certainty that the camera was seeing what I thought I was sending.

author: Vipitis
author_rank: Frequent Contributor
timestamp: March 29, 2021, 03:35:52 pm
content: A little update: I have exhausted all the software settings(new line, flow control) and got no results. I start to believe that this is some hardware limitation that I fail to see with a multimeter.It will probably take me a while to read up on scopes and find one that I want to get, buy one and get familiar with how it works. But being able to look how far the signal is going will allow me to pin point the potential roadblock.If there is no further ideas, I hope to reply here with new data in a few weeks maybe.

author: Fraser
author_rank: Super Contributor
timestamp: March 29, 2021, 06:12:07 pm
content: Hi Vipitis,I have looked through the Thermoteknix documentation for the RS232 communications and could find nothing unusual about the implementation on your camera. You should be able to just hook up TX, RX and 0V to achieve communications.Fraser