Hardware design for conditional operation

Thread Starter


Joined Apr 23, 2022
Hi there ladies and gents,

I'm just putting together a board where I can host three ESP-32 development boards, which will be connected on the IIC bus.
ESP32 dev board.jpeg

The connections are
1 x 10 pin connection to attach a Saleae clone logic analyzer.
1 x 6 pin connection to attach an ESP-PROG JTAG board.
1 x power souce -not in the picture, and will probably be a terminal connector, rather than a barrel connection, etc.

The push button is used to switch the JTAG connections between the three development boards or none, and the 7-segment display will show 0,1,2, or 3 to indicate which board is currently connected via JTAG.

When a development board is connected via JTAG, the power will be sourced through this connection, so it will need to be disconnected from the main power input of the whole board.

I could introduce an 8-bit MCU to handle the logic for button presses etc, however I really want to better understand how I could achieve this via hardware rather than software, but I really do not know where to start.

I've been considering a shift register, a 555 timer and an EEPROM for storing button presses to determine which board is active on the JTAG connection. I've also been thanking that maybe I need another couple of buttons on there (one for clearing, and one for storing). I'm not sure what I need to use for the actual switching, I've been thinking of something like a TS1245 SPST IC.

The bottom line is that I'm clueless when it comes to hardware, and I feel that this is an ideal opportunity to start learning.

Is there anyone whom can help me acquire the missing knowledge please?