Hi all,

I will select with two gpios (in binary mode) between 4 difference volumes. How can i realize that? i tried with demuxer, but i cant get the binary bit combination...

thanks for helping

best regards, hubijo

Hi all,

I will select with two gpios (in binary mode) between 4 difference volumes. How can i realize that? i tried with demuxer, but i cant get the binary bit combination...

thanks for helping

best regards, hubijo

Hello hubijo,

There's several ways to do it, one is shown below. Condition the GPIOs with

**buffer gates**, each of which produce a selectable high bit output for a nonzero input. In the -1701 and similar DSPs with a 5.23 format, the bit positions**20**,**21**, and**22**provide a**1/8**,**1/4**, and**1/2**value respectively. Summing these provides the binary-coded result you desire.Using the 1701 mini board, set your HW control for

**MP2**and**MP3**to**invert**, then the volume increases when you press switches**S3,****S4,**or**both.**Bob

Hi,

I included the

**DC Source DC1**to set a minimum level for when the two binary inputs are both off. Use a DC Source anywhere a constant numerical value is needed.The DC Source block lets you choose both the numeric value of your constant and its format -- how many binary bits appear before and after the decimal point (actually the correct term here would be "binary point."). See http://ez.analog.com/docs/DOC-3168

for help with the number formats in SigmaDSP.

Bob

Hello hubijo,

There's several ways to do it, one is shown below. Condition the GPIOs with

buffer gates, each of which produce a selectable high bit output for a nonzero input. In the -1701 and similar DSPs with a 5.23 format, the bit positions20,21, and22provide a1/8,1/4, and1/2value respectively. Summing these provides the binary-coded result you desire.Using the 1701 mini board, set your HW control for

MP2andMP3toinvert, then the volume increases when you press switchesS3,S4,orboth.Bob