[Oberon] PO2013 - Real time measurement

[Paul Reed]

Hi Tomas,

> I wish to do some real time input from basic sensors...
> [a]... Arduino can do A/D conversions for Oberon while it can talk over
WiFi,

Just to be clear, the nRF24L01 chips used with Oberon on the FPGA do not
do WiFi, but they use the same 2.4GHz bands.  Other chips can do WiFi.

> [b]... PIC processors can also do A/D conversion. PIC can possibly
> interconnect through GPIO, while I cannot see an easy way to add more
> devices to the hub (* multiplexing GPIO input???*). It also has some
> leverage in NW's PICL project.

I would definitely recommend PIC.

I have successfully used the PIC16F1455 (5V), the PIC16LF1455, and the
PIC16LF1459 (both 3.3V) as well as some of the older chips, even the
PIC16F84 which is the  replacement for the PIC16C84 Prof. Wirth refers to
on his PICL page.

His PICL compiler targeted this PIC16C84 which is quite a bit simpler than
modern PICs, which have A/D, D/A, signal generation, PWM, even USB
(device) but at least with the PICs, the added complication is only due to
the added features. :)

Nevertheless I found it very easy to extend the compiler to add features
for modern PICs (e.g. bank-switching) and in many cases such large changes
wouldn't even be necessary.

Prof. Wirth also provides an example of using a PC parallel port to
control (multiplex) two PIC chips, which you could easily adapt for the
FPGA.  The main thing to remember is that with the FPGA you will want to
use the 3.3V versions (LF) not the 5V versions (F).

Having done a lot of nRF24L01 programming, you should also be very well
placed to connect a PIC SPI port directly to the nRF24L01 module,
programmed in PICL, to create a remote self-contained "sensor node", if
you wish.

I thought of doing this using an MSF radio-controlled clock for the
timeserver in the ETH classes, but time did not allow (no pun intended!),
and a Raspberry Pi or a PC serves just as well in practice.

Let me know if I can help further.
Best regards,
Paul