Hi,
Please be gentle, I have an OBLS that I am trying to figure out how to use it.
Basically I have an alarm 433mhz remote TX and siren RX, so I connected to the data and gnd pins of the RX and when I press the remote button I would like to see the binary code being sent to the MCU in the siren.
I am new to all of this, so I am having issues, so I loaded up OLS and am able to capture something, I don't really understand how to view what I am seeing properly and how to use triggers.
Under Tools I see the Line Decoder, a lot of these 433Mhz gadgets use manchester encoding so this could be useful.
Can somebody please help me out.
Thanks.
Richard
What you are capturing is a snapshot of the signals' logic level at a certain interval (= the sample speed). If this sample speed is high enough, you can accurately deduce the information that was sent across the line. As a rule of thumb, you should set the sample speed to roughly 5-10x the signal speed to get an accurate capture. So, if the signal speed is, say, 10 kHz, you should set your sample speed to 100 kHz to get a good capture.
Now, as you start a capture without triggers, it will start and sample the line immediately, probably filling up your capture memory with useless information. To overcome this, you can set a trigger to wait until a certain condition has occurred. Suppose your RX-line is normally low, you might want to start capturing from the first transition from low -> high.
In the trigger settings of the OLS client, you should enable the trigger settings, and enable the mask and value checkboxes for the channel on which the RX is captured (for example, channel 2). The mask tell the OBLS which channels it should watch for the trigger condition, while the value tells it what value it should expect. You need to check both the mask and value checkbox to start capturing on the first low -> high transition. You can choose the amount of information to include before and after the trigger with the big slider on the top. If you're only interested in the information after the trigger, you can select a ratio of 0/100%.
If your capture is now complete, it should display a nice trace on your screen, which, upon recaptures, should remain rather "stable" in the sense that it should always start at the same location. Now you can use one of the decoder tools to decode the information you've captured, which is not much more than selecting it from the "Tools" menu, filling in the settings, and hitting "invoke".