Electronic – arduino – How to short two nodes electronically

arduinoinfraredmultiplexerrc5

I am using a Phillips SAA3010 IR transmitter IC to send a modulated IR signal. The IC has two types of inputs:

  • Z0—Z3
  • X0—X7

And one type of output:

  • DR0—DR7

Each legal operation corresponds to a wired connection of DR-Z and DR-X pin. The device is designed to be interfaced with a keypad on a remote control, per the datasheet description:

Every connection of one X-input and one DR-output will be recognized as a legal key operation and will cause the device to generate the corresponding code. The same applies to every connection of one Z-input to one DR-output with the provison that SSM must be LOW. When SSM is HIGH a wired connection must exist between a Z-input and a DR-output. If no connection is present the system number will not be generated.

The desired switch arrangement is described in this figure from the datasheet:

enter image description here

However, I want to do the wired connection electronically, so as to make the switch programmable via an Arduino. I have to obtain 64 such legal key connections. I have tried using a MUX/DEMUX IC but as they use gates, no wired physical connection exists. I believe that this will not work unless there is a wired physical connection. The datasheet certainly assumes that a physical keypad will be used.

How can I do this using the minimum possible space? My physical limitations are that the device has to be about the size of a typical mobile phone, which includes the Arduino UNO board.

Best Answer

Take the problem one level up. Do you want to control the SAA3010 (which has been obsolete since eons) with a microcontroller or do you want to send RC5 codes. I guess you want the latter. One of the reasons the SAA3010 is obsolete is that these days about every device contains at least one microcontroller, and microcontrollers can do this task as easily as the SAA3010, including the modulation.
I've never used Arduino, but I guess it can output RC5 codes. If it can't, or if your Arduino doesn't have the resources left, use an external microcontroller which you control through UART. This will probably cost you less than a few of the switches you would use on the switch matrix, so it's definitely the cheapest solution.

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