Monthly Archives: August 2013

MEGA-1284 Logic Analyzer – Viewing UART Signals

Now that you have a MEGA-1284 Logic Analyzer, it is time to view some data signals.  We will start with a UART off of another Arduino, since it is a fairly explicit communications protocol.  I loaded the ASCIITable sketch from the Arduino IDE to generate the communications on the Arduino.  Disconnect the USB and jumper from the power rails 5v0 and GND to the header pins 5v0 and GND on the Signal Arduino.  Then simply connect Channel 0 (D16 or chip pin 22) on the MEGA-1284 Logic Analyzer to D1 (TX) of the Signal Arduino.  You should be ready on the hardware side, so go ahead and plug the MEGA-1284 Logic Analyzer into the PC.  Then, startup the Open Logic Sniffer client application.

Click on <Capture> and <Begin Capture> to open the “Connection” tab and verify connection to the MEGA-1284 by clicking the “Show device metadata” button.  Information show populate the fields below the button.  If not, you will have to verify the connection settings are correct.

Click on the “Acquisition” tab and change the “Sampling rate” to 20 kHz.  At 9600 bps, 10 kHz should suffice, but I was getting noise in the data and the Noise filter is not developed yet for the MEGA-1284.  Click on the “Triggers” tab and click a check in Mask 0 (Channel 0) and nothing in the value for Mask 0 (trigger will occur from a HIGH to a LOW).

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