PL_DAQ - Analog and RS-232 data acquistion system
PL_DAQ is a simple data acquisition system, able to collect data from different
biomedical monitoring devices. It offers 8 analog inputs and 8 RS-232 inputs.
The collected data may be sent to the data processing PC using the Ethernet
or USB connection
Currently the following documentation is available:
- Schematic diagram in gschem format
- Printout of schematic diagram in PDF format
- Printed board (designed by Wojciech Zaworski) in PCB format
- Netlist file
Next parts of documentation with firmware and software will be released later.
There is one possible problem with that design.
The clock used for SCLK in SC28L198
is not synchronous with the clock of ADuC832. However Philips puts some
requirements regarding the time between the active slope of clock signal
and falling slope of the CE signal. Philips does not state if not meeting
this requirements may result only in one clock delay of read/write cycle
(not significant if we use relatively slow ADuC832 bus and asynchronous
mode of SC28L198), or if it may lead to serious metastability problems.
I've tested the prototype and no corrupted reads/writes have been
observed. However they can be very rare.
You can use ADuC831 instead of ADuC832, and use the common 16MHz clock
for both ADuC and SC28L198. Here you can find
the modified
schematic and
its printout
and the modified PCB with the
netlist.
The PCB is double sided.
The single track on the "unused" layer denotes wired clock connection.
Links to other free & open simple data acquisition systems:
Wojciech Zabolotny
Last modified: Sat Jul 9 11:22:25 CEST 2005