Hi Mauried,
Thank you for taking the time to have a look at my issues.
mauried:
The Hc12 is a bidirectional transceiver, but only at the data input output port.
The RF link is uni directional, and has to be periodically turned around to allow the data port to appear to be bi directional.
The type of data you are sending, the data rate and any pauses in the data being sent will impact on the ability of the data to be received properly.
Try reducing the data rate of whats being sent, and leave gaps in the data so its not continuous, and see if that improves.
I am tricking around today with introducing delays to see the impact.
Of note: The timing module - countdown - works flawlessly regardless of whether or not I have both Rx in play. It is the command to enable the matrix controller/screen setup and the small animation setup that are affected, so I will be looking hard at these areas.
In the case of the matrix setup, I appear to miss a crucial "inverse" signal on one and fail to initialise entirely on the other, resulting in one (either, randomly) screen being in negative, and the other just blank.
In the mini animation (letters scooting across the screen) the font/size parameters sometimes jumble, and in nearly identical fashion on both screens. Both of these faults are completely absent when only one screen (Rx) is in use. Rebooting the Tx (which results in a reboot of the matrix controller on the Rx side) can clear the fault 3/5 times. I wonder if my issues will worsen with 3, or 4 screens?
mauried:
The more receivers there are, the more the transmission link has to be reversed.
I'm not at all sure what you mean by this.
I haven't even got the Serial Transmit pin connected on the Rx unit side, not the Receive on the Tx side, as I'm deliberately attempting to keep the data flow mono-directional, and as an approach with this setup it seems to work since I'm happy for the Rx units to 'pick up' where the stream left off if any data is lost in Tx due to occlusions or interference. It is a timing system, and the timing stream is the important thing.
mauried:
A HC12 is not really a good solution to what you are trying to do.
You would be better off with something simpler like one of the cheaper 433 Mhz OOK transmitters and receivers using Virtualwire.
Looking at these units I see they are incapable of Serial data transmission/reception: "Can we use Serial communication with ? answer is No
ASK receivers require a burst of training pulses to synchronize the transmitter and receiver, and also requires good balance between 0s and 1s in the message stream in order to maintain the DC balance of the message, UARTs do not provide these. They work a bit with ASK wireless, but not as well as this code."
mauried:
The only other way to make this work is to set each receiver on a differant radio channel and then cycle the transmitter through the differant channels transmitting the same data each time.
Sadly this is also not an option afaik, as I am expecting each screen to show the time simultaneously, and to sound off Zero at the same instant. A cascade effect would surely be the result in such a setup?