JP1 Remotes

I have an old MAK Maxi 2000 universal remote control. There is some 7-pin connector on the PCB. There is also an AT45DB011-SC SPI chip. I checked the pins with a meter:
https://www.hifi-remote.com/forums/dload ... e_id=26380
https://www.hifi-remote.com/forums/dload ... e_id=26381

If I connect the RXD pin of the USB-TTL converter to SO and the GND mass, then in the SerialWatcher program I have some data when pressing the buttons on the remote control:
https://www.hifi-remote.com/forums/dload ... e_id=26382

The files posted are all images, so here are the images:







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https://www.hifi-remote.com/forums/viewtopic.php?t=6557

What is the RTS line voltage? I have a universal remote control, but without user manual and without pin markings on the PCB. I want to check with the DT830 multi-meter.

I have such voltage on the pins in my remote control:

Remote have 28-pin chip EL-2000. With such a connection of the remote control to the USB-TTL converter, after clicking the Download button in the RMIR program, the diode on the remote is blinking:

RTS - 1
TXD - 3
RXD - 4
GND - 7

jzef wrote:What is the RTS line voltage? I have a universal remote control, but without user manual and without pin markings on the PCB. I want to check with the DT830 multi-meter.

I'm not sure what you are trying to achieve with your multimeter, but the nominal voltage of all output pins is 3.0v and input pins normally have a pull-up resistor that will make them also read as 3.0v, so you cannot distinguish between pins by their voltage.

mathdon wrote:nominal voltage of all output pins is 3.0v

OK, Thx.