Help with Pic Delay Pulse code please

[Melanie]

OK, that's good, we know the PIC works...

Now from your Posts I assume the following...

1. InputTrigger goes Low... this causes OutputLine to go Low
2. If the InputTrigger < 1 Second then OutputLine is held on by DelayTime
3. If the InputTrigger => 1 Second then DelayTime is Terminated
4. And you want a Blinky

Thinking about it... is it as simple as the following conditions (this isn't PBP code btw)...

If InputTrigger < DelayTime then OuputLine = DelayTime
If InputTrigger => DelayTime then OutputLine = InputTrigger

?

[Chris Barron]

OK, that's good, we know the PIC works...

Thinking about it... is it as simple as the following conditions (this isn't PBP code btw)...

If InputTrigger < DelayTime then OuputLine = DelayTime
If InputTrigger => DelayTime then OutputLine = InputTrigger

?

That seems to be the goal (That's what i read into it anyway)

The output signal of the RF repeater is switched when the input signal is switched, but sometimes the received signal can be 'choppy' (Like any mobile radio signal, the signal strength varies wildly depending on terrain and the movement of the antenna)

If the input signal is very short it is assumed to be a choppy signal, and the output is held on because if the signal is choppy it will be restored very soon. The idea seems to be to keep the output RF stages switched on so that they transmit in the 'dropout' period too for the case of a choppy input signal.

If I get a chance later I'll flash the code I wrote into a pic and see what happens.

In the meantime,Dave (Don't know where Jeff came from !) sticking with the LED flashing diagnostic technique, each subsection of the program can be modified to flash the led for a different number of times, that way you will know which sections of the program are being run and which aren't

As another idea, if you are using a pickit2 to program it has a great serial USART device built in which saves you having to build a level convertor and that would let you SEROUT messages to it (for display on the PC) which could tell you where the program execution goes.

Chris

[Melanie]

The output signal of the RF repeater is switched when the input signal is switched, but sometimes the received signal can be 'choppy' (Like any mobile radio signal, the signal strength varies wildly depending on terrain and the movement of the antenna)

That doesn't equate to the new requirement as described... if for example you have had good reception for say 5 seconds and then your signal starts to break up, because the DelayTime has elapsed the repeater will disengage immediately. You should have your Repeater timeout only START at the end of reception and if reception is re-enabled within the timeout period, then you simply go back to the start with the Transmitter still holding on. That way, as long as reception re-occurs within the 1 Second Time-Delay the repeater is still held on... so this now becomes (in a simplified form)...

Loop:
If InputTrigger=0 then OutputLine=0
If InputTrigger=1 and TimeDelay>1Second then OutputLine=1
Goto Loop

You should also consider a secondary feature... an additional timeout to disengage the Transmitter regardless if it has been held on for say 15 minutes continuously (in case of some localised lock-up in the repeater receiver from it's own transmitter).

[Chris Barron]

That doesn't equate to the new requirement as described... if for example you have had good reception for say 5 seconds and then your signal starts to break up, because the DelayTime has elapsed the repeater will disengage immediately. You should have your Repeater timeout only START at the end of reception and if reception is re-enabled within the timeout period, then you simply go back to the start with the Transmitter still holding on. That way, as long as reception re-occurs within the 1 Second Time-Delay the repeater is still held on... so this now becomes (in a simplified form)...

Loop:
If InputTrigger=0 then OutputLine=0
If InputTrigger=1 and TimeDelay>1Second then OutputLine=1
Goto Loop

You should also consider a secondary feature... an additional timeout to disengage the Transmitter regardless if it has been held on for say 15 minutes continuously (in case of some localised lock-up in the repeater receiver from it's own transmitter).

I thought it a good idea to just keep the one second delay too, but for some reason it seems to have caused Dave a problem not to have. You make a very good point regarding a good signal transitioning into a bad one over the course of one reception period, and that alone probably justifies keeping the delay on all transmissions.

Often you hear amateur operaters stop transmitting to check if they still have the repeater control, which indicates that the TX signal is still strong enough to keep the repeater's RX output switch engaged

The tx/rx lockup prevention is already taken care of by the rx/tx frequency offset, which is 0.6MHz for the 2m band (144-146 MHz) and 1.6Mhz (or 7.6MHz) offset for the 70cm band (430-440MHz approx)

[g7jiq]

Hi Melanie and Chris

Many thanks for all your input,
Yes your final configs are about right, both of you added points I hadn't thought of,

(The repeater controller is for a small low power unit, the timeout/lockup watchdogs are incorporated in the main radios, so are not required.)

1. InputTrigger goes Low... this causes OutputLine to go Low
2. If the InputTrigger pulses at anytime that InputTrigger is Low < 1 Second then OutputLine is held on by DelayTime
3. If the InputTrigger => 1 Second then DelayTime is Terminated
4. And I want a Blinky for diagnostic.
5. If possible an led to display whether the delay has been triggered, (this would be an added diagnostic function and a help when setting the rx radio up)

It needs to self monitor for InputTrigger pulses for as long as InputTrigger is Low, and self cancel if InputTrigger stops pulsing.

Hope this is makes sense,

Cheers
Dave..

[Melanie]

OK, it's not the way I would do it... but I can see your logic...

As long as InputTrigger keeps pulsing, the Delay Timer keeps resetting back to the start as long as the Delay Time hasn't already expired, during this time OutputLine will be kept Low. If the Delay Time has expired then on the first occasion InputTrigger goes High, then so does OutputLine.

You have a 2Hz Blinky (which stops whilst you do an Input Reset).

And you have a DelayLED for your Diagnostic purposes...

[g7jiq]

Hi Melanie

Many many thanks for the code,
I have given it a try, (like the diagnostic leds)
Just a small thing,
Can you tell me where the hang delay value is, and for some reason I get a delay nearly all the time, even after a 30 sec TriggerInput. Any ideas..??

Apart from that its just what I was looking for.


Thanks again,
Cheers
Dave...

[Melanie]

Don't know what you're doing... I just breadboarded to test what I wrote and it works as expected. The DelayLED goes out if InputTrigger is constantly ON (solid ON) for 1 Second (that's active pulled LOW). If InputTrigger fluctuates, then DelayLED will be on all the time. You got AC coming down the line into InputTrigger? You forgot you need external Pull-Up's on the InputReset and InputTrigger?

The Delay value is one of the two Constants defined at the start. Change that to change the Timeout.