Hello Sooryakrishnan U:
Noting relevant (printable characters) should is sent, so it is normal to see junk. In fact if the terminal uses the same Virtual COM port than the one used to communicate with the Medical GUI, that will cause problems. So please do not use any terminal while testing the demo.
About the signal problem, here are some suggestions to correct it:
-> Carefully check that the jumper configuration for all 3 boards is correct: TWR-K53, TWR-SER and MED-EKG. I attached the PDF with the jumper settings.
-> Match the Primary and Secondary elevators to the corresponding sides in TWR-K53 and TWR-SER boards.
-> Confirm that the MED-EKG board makes good contact with the MCU board medical connector header.
-> MED-EKG on-board electrodes do not give a very stable signal. It is highly recommended to use external electrodes (wires + patches) or create your own electrodes, see this appnote: AN4223.
-> In case of using the on-board finger electrodes, press firmly each pair of electrodes (left and right) with the fingertips of your middle and index fingers of each hand while holding the bottom of the board with your thumbs. See this picture:
-> If using wires + patches make sure to connect the reference wire (black) in the middle pin of the MED-EKG connector, and for the position of the patches on your body refer to chapter 3.3.3 in the next document: http://cache.nxp.com/files/32bit/doc/ref_manual/DRM141.pdf
-> If using a laptop, it is also a good idea to disconnect it from the power supply network and use it battery-only.
I hope these suggestions help.
Regards!,
Jorge Gonzalez
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Hello,
Please read the Appendix B Communication Protocol from application note AN4323.
You can actually control the MED-EKG demo with a terminal without using the Medical GUI, but I think Teraterm cannot print values in hexadecimal format and neither you can send any hexadecimal data. Try installing a Terminal program that can do both: receive/print hexadecimal values and send hexadecimal values.
In the appendix you will see that it is possible to start the EKG measurement by sending 0x52 0x12 (REQUEST packet for ECG_DIAGNOSTIC_MODE_START_MEASUREMENT). Then you can retrieve all the signal information from the INDICATION packets. See below an example:
Regards!
Jorge Gonzalez
