Electronic – arduino – Interface between DAC and galvanometer board

If understand correctly you are looking for a simple multiplexer, something like the 74HC4067 should do - it's a 1 to 16 multiplexer/demultiplexer.

Simply input your signal to pin 1 (COM IN/OUT) and use S0 to S3 to switch it between I0 to I15 (each of which are connected to your Arduino inputs) For example if you want to connect to I7, then you set S3 to 0, S2 to 1, S1 to 1, S0 to 1 (i.e. 0111 binary = 7 decimal)

This is a single supply IC, so it won't work if you DAC swings below ground, in that case you will need a dual rail mux (plenty out there, e.g. 4051 is an 8ch dual rail)

There could be a couple potential causes for this depending on the magnitude of the DAC output and how this signal is driven to the ADS1299. The DAC may not have the required drive strength capability, so added impedance to the signal path may cause this problem. You may need to buffer the DAC's output.

I have posted your question to TI's E2E forum at the link below. My hope is that other community members will see it and that you can provide more information about your design.

http://e2e.ti.com/support/data_converters/precision_data_converters/f/73/t/328451.aspx

Best Regards,

Ryan