linux device driver - Reading multi-channel serial usb in pure data -

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i have multichannel serial data 8 channel adc chip i'm connecting computer via serial-usb cable. want use these separate channels in pure data, pd_comport object doesn't read multi-channel serial data. i've scoured pd discussion fora there's no mention of how this. thoughts on how can go it?

per definition serial connection single-channel. if have multiple (synchronized) channels, it's called parallel.

so problem 1 of 2 following:

parallel serial streams

if transmitting 8 adc-channels via different serial connections, (special) cable should register 8 different devices (e.g. /dev/ttyusb5, /dev/ttyusb6, .../dev/ttyusb12). in case, use multiple [comport] objects (one each serial device want interface)

single multiplex stream

in (more likely) case, adc transmits it's 8 channels in single serial connection multiplexing data, have demultiplex serial stream yourself. how this, depending on actual format of data.

assuming adcs 8bit , have 4 channels (for simplicity), might receive serial stream like: ... a1 b1 c1 d1 a2 b2 c2 d2 a3 b3 .... (with a, b,... being samples 4 channels; , 1,2,... being sample frames), demultiplex signal 4 streams like

| [t b              f] |                  | |  +------------+  | [i ]/[+ 1]/[% 4]/  | |                  | [pack      0      0] | [route 0 1 2 3] |  |   |   |

in practice protocol might different (e.g. there ought way specify frame boundaries (there's no way looking @ numbers, whether seeing a1 b1 c1 d1 a2 b2 or b1 c1 d1 a2 b2 c2, it's unclear whether 1st sample belongs channela or channelb).

thus must hands on protocol definition , interpret data [comport]


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