Great news Goeytex. Your dedication is appreciated.UPDATE:
Success with the Dorji DRF-1212 Modules using 14M2's for intelligence. This tells me several things.
1) Half Duplex RF Modules should be OK.
2) 14M2's can handle the task ( Not enough I/O's on 08M2). This means that a faster non-Picaxe is not required for "intelligence" and that "firmware" can be upgraded via PE. Different RF Modules / Different Firmware.
3) No extra USB/TTL adapter is necessary. AXE027 works OK. The 14M2's handle the necessary RX/TX data inverting and baud rates to the RF modules.
Here is a crude Block Diagram. I will post schematics and code next week.
View attachment 25030
One well known issue with any microcontroller is parasitic powering. They may keep running if the power to the chip is disconnected but the chip gets its power through I/O pins. If they do keep running while getting that power they won't actually reset. That, plus the fact that it's difficult to control just the power to the microcontroller unless the target hardware is designed with that in mind, may mean having to disconnect the supply to the entire target.. That can mean switching quite high currents, even multiple voltage rails.For one worse case scenario, where the target Picaxe has "disconnect" enabled, I may need to add a bit of circuitry on the remote side that forces a hard reset on the target Picaxe
I would say it's probably because most people following the Hard Reset procedure will be powering the 'whole lot' off and back on, so it doesn't usually cause an issue.Parasitic powering will certainly need to be addressed on target side in order for a hard reset to work. While it may be "well known" issue, preventative measures seem to be neglected by many in their circuit designs, either because they don't know, don't care, or because it seemingly has no effect until they try a hard reset, or when they remove V+ from the microcontroller and wonder why it is still running.
Possibly a few factors; the issue of only being useful in a limited set of circumstances, the challenge of making it more universal, the having to do it and make it work, perhaps lack of demand for having it, it not giving a good return on investment, and the problem of wireless parts used being superseded or difficult to obtain, rendering it prematurely end of life, in need of a redesign, quite a lot more work, with potential incompatibilities.I am NOT trying to clone the mighty (but long defunct) Ciseco devices, yet I wonder why Rev-Ed has not taken up the mantle on this.
That's the luxury of not providing a commercial product which customers expect to work for what they want to do, who expect the supplier to make it so.Sod's Law may come in to play, however Goey's Law says that if you don't like it, either help to improve it or get out of the way.
Guilty as charged, I nabbed the last one, supremely confident in your abilities.@erco
Those are the ones. DRF1212-D10. However no stock anywhere, as is the case with many IC based devices nowadays. You know, the "chip shortage" and all that stuff.. I just happened to have a few on hand, left over from a project I did in 2015/16.
I would advise to hold off on ordering...
All the M2 chips have a Data Signal Modulator (DSM) which can allow an inversion on-chip independent of what else the PICAXE is doing which can save on needing additional hardware.To lessen the load on the intermediate 14M2's, and to mitigate the related processing delays, hardware inverters were added to each circuit.
Symbol MDCON = $FC ; SFR $39C Symbol MDSRC = $FD ; SFR $39D Symbol MDCARL = $FE ; SFR $39E Symbol MDCARH = $FF ; SFR $39F PokeSfr MDCON, %11000000 PokeSfr MDSRC, %00000001 PokeSfr MDCARL, %01000000 PokeSfr MDCARH, %00000000
There is only one DSM but I would have thought you would only need one inversion, the other done within the 14M2, though I guess it does depend upon how you are doing things -Looking at the datasheet, there is only 1 DSM module. This possibly allows for the inversion of only 1 signal without jumping through hoops. Both the serial output of the RF module and the serial output of the AXE-027 need to be inverted.
| .----. .----. .----. .----. .--------. |-->|14M2|-->| | | |-->|14M2|-->| | PC | `----' | RF |= =| RF | `----' | TARGET | |<---O<|-----| | | |<---O<|-----| | | `----' `----' `--------'
That's fair enough. I was thinking more about the next step once what you have is working. Other people will be more inclined to build something when it's a bare minimum, just a couple of 14M2 and RF modules wired together without additional components.And honesty, at this point ( near completion) I'd rather not be poking around in unsupported peripheral registers unless absolutely necessary.
Amen, Brother Goey! A slight increase in parts count is a one-time delay during construction, vs perpetual delays in operation. My RF modules arrived already, amazingly fast ship. No time to build yet, but this will be a great Christmas turkey project.Right now we are looking at 2 NPN transistors and 6 resistors along with the RF module and the 14M2. I imagine this to be within the skill set of anyone seriously interested .
I did a little work with them but don't recall doing any testing regarding current consumption, sleep modes or wake-up.I'd no experiences with the CISECO offering from a decade back but assume such overheads were then considered. Did anyone work with them? Hippy?
My main concern was that everything extra which is needed can be something which puts people off. That won't be a hindrance to those who are determined to have it but can reduce the audience which might be interested in it. A few extra components shouldn't be an obstacle but people are fickle things and for some they will be.Amen, Brother Goey! A slight increase in parts count is a one-time delay during construction, vs perpetual delays in operation.Right now we are looking at 2 NPN transistors and 6 resistors along with the RF module and the 14M2. I imagine this to be within the skill set of anyone seriously interested .
I thought we'd ascertained it was because some of them have dodgy (ie not 30MHz) crystals?As I understand it, HC-12 modules with different firmwares cannot communicate with each other, even when set up to the same frequency/ baud rates. (Based on customer reviews at Banggood)
I turned my firewall off for long enough to have a look at this (I have a country block for China ) ...
Sounds plausible - so I thought I'd have a quick look at a much older one ..."44382A " does start with "4438" so that might be a valid assumption ;-)