However a less obvious aspect is the speed at which the AGC and middle of signal, point stabilizes. If it is too slow, it may not reflect/capture incoming headers/data quick enough. If the header is short, say around 10 bits, this can be rather crucial.
Quote from: robwlakes on Sep 02, 2014, 01:20 amHowever a less obvious aspect is the speed at which the AGC and middle of signal, point stabilizes. If it is too slow, it may not reflect/capture incoming headers/data quick enough. If the header is short, say around 10 bits, this can be rather crucial.Is that an aspect you can cover selecting the proper parameters with Virtual Wire?
How quickly the Rx circuit stabilises the bias before the data arrives, would depend on the the strength of the signal and/or the length of the header(headers have equal on to off time ratios for this purpose, and stronger signals would pull the centering biasing circuit in quicker) rather than the bit rate. Once the RX is stabilised in the header then the bit rate should not be so important eg to be longer than 1 mS. I think I would try more header bits in the Tx stream if I had control over that. Set the Rx to look for 25%-50% of them before accepting it as a valid header. eg 60 header bits Tx'ed, and >= 25 Rx'ed means a Valid header
Ah very nice combo, I am also partial to a bit of Raspberry Pi
and I like Python.
I reckon you are going ok then, leave the software for a while, and see if the getting the raw signal strength up by trying antennas (I read recently a 17cm strand of Cat5 Cable wire was effective for 433MHz Tx &Rx)
and supply voltages (I think the Rx was kept at 5V but the Tx was keyed with a 9or12V power supply??? Just check the specs on the Tx) will get you over the line.
Have you had a read of this advanced/replacment version of Virtual Wire? I haven't used it but it looks well documented so could be worth a read.