I have a thread on another forum, but so far I haven't been able to get two PIC PCBs with HC-12 radio modules to RECEIVE and switch a LED ON/OFF.

I have two PCBs each with an HC-12, also a serial input to a computer READing from a 3rd HC-12 onto a Terminal.

Both PCBs TX and are RXed on the screen ok.

I've tried to send '0' and '1' as a switch from TX, and the RX shows some results, but not clean LED ON/OFF.

This is in Oshonsoft.

Here's the latest TX and RX CODE:
This gives RLED always ON, YLED sometimes ON/OFF
I tried many > and < numbers, and found =106 worked 50% of the time for some strange reason?

Any help please?
Camerart.

TX:--------------------------------------------------------------------------------------
For x = 0 To 1000
rled = 0
yled = 1
Hserout "0", CrLf : ALSO Hserout "1", stri, crlf: ALSO Hserout stri, crlf
Next x

For x = 0 To 1000
rled = 1
yled = 0
Hserout "1", CrLf
Next x

RX:--------------------------------------------------------------------------------
Hserget i
If i = 0 Then '< --- -- 48 is number 0
Hserout "Number: ", i, CrLf
rled = 1
WaitMs 500
Endif

If i = 106 Then '= 106 Then '< --- -- 49 is number 1
Hserout "Number: ", i, CrLf
yled = 1
WaitMs 500
Endif

 

hi C,
Why have you used Loops to Send a data string.?

E

EDIT:
This is a edited clip from my HC12 receiver program.

 

Hi C

I did answer on t'other place but when there is work in I have to get it done..

 

I have a thread on another forum, but so far I haven't been able to get two PIC PCBs with HC-12 radio modules to RECEIVE and switch a LED ON/OFF.

I have two PCBs each with an HC-12, also a serial input to a computer READing from a 3rd HC-12 onto a Terminal.

Both PCBs TX and are RXed on the screen ok.

I've tried to send '0' and '1' as a switch from TX, and the RX shows some results, but not clean LED ON/OFF.

This is in Oshonsoft.

Here's the latest TX and RX CODE:
This gives RLED always ON, YLED sometimes ON/OFF
I tried many > and < numbers, and found =106 worked 50% of the time for some strange reason?

Any help please?
Camerart.

TX:--------------------------------------------------------------------------------------
For x = 0 To 1000
rled = 0
yled = 1
Hserout "0", CrLf : ALSO Hserout "1", stri, crlf: ALSO Hserout stri, crlf
Next x

For x = 0 To 1000
rled = 1
yled = 0
Hserout "1", CrLf
Next x

RX:--------------------------------------------------------------------------------
Hserget i
If i = 0 Then '< --- -- 48 is number 0
Hserout "Number: ", i, CrLf
rled = 1
WaitMs 500
Endif

If i = 106 Then '= 106 Then '< --- -- 49 is number 1
Hserout "Number: ", i, CrLf
yled = 1
WaitMs 500
Endif

do you have https://www.elecrow.com/download/HC-12.pdf ?
Did you give attention to the timing?
Picbuster

 

Hi C

I did answer on t'other place but when there is work in I have to get it done..

Hi I,
I will keep trying your code from t'other place, but previously on my TRACKER program, E, used a different method to glean DATA from a GPS, which is a bit more complex, but works ok. I hoped he would send me something similar for the HC-12s and he did in #2, which I need to read for a while to follow and understand.
Now get back to work
Cheers, C.

 

hi C,
I try to write a program in a general way that can be later expanded as required , you are being too specific.
eg:
Send a message that can carry more data/instructions to the remote receiver.
hserout "Axyz",crlf
Using 'A' as a RXR ID sync character [ A thru Z are available]
x, y, z characters/numbers can specify the action required a the RXR end. [ a thru z, lower case, 0 thru 9]
Limit the TX rate to say 0.5 Sec, to give the RXR time to execute the command and ECHO back if commanded to do so.

At the RXR, use RX/serial interrupt
On Interrupt check for Overflow Errors, clear as required.
Test for the Sync Character for that particular RXR, ie: 'A' etc
If ID is valid, get the rest of the message upto the crlf code

You can then use midstr to test the message content,
If midtsr(rxd,p,n) then ' to pick off a character or group of characters
if a match, then do something.!

One of the do something characters could be an command ECHO to send an 'OK' message back to the TXR. [ or any other data msg]

E

 

hi C,
I try to write a program in a general way that can be later expanded as required , you are being too specific.
eg:
Send a message that can carry more data/instructions to the remote receiver.
hserout "Axyz",crlf
Using 'A' as a RXR ID sync character [ A thru Z are available]
x, y, z characters/numbers can specify the action required a the RXR end. [ a thru z, lower case, 0 thru 9]
Limit the TX rate to say 0.5 Sec, to give the RXR time to execute the command and ECHO back if commanded to do so.

At the RXR, use RX/serial interrupt
On Interrupt check for Overflow Errors, clear as required.
Test for the Sync Character for that particular RXR, ie: 'A' etc
If ID is valid, get the rest of the message upto the crlf code

You can then use midstr to test the message content,
If midtsr(rxd,p,n) then ' to pick off a character or group of characters
if a match, then do something.!

One of the do something characters could be an command ECHO to send an 'OK' message back to the TXR. [ or any other data msg]

E

Hi E,
First I'm trying to get a LED to ON/OFF in the simplest way, so if I can get I's suggestions to work, from t'other forum, I'll use that to get the feel of things. I'm sure I can think of many simple uses for it.

Depending on how I understand your suggestion, and remembering that it will be LOOPed in a longer program with lots going on, I will probably use it in the MAIN program.
Thanks, E.

 

do you have https://www.elecrow.com/download/HC-12.pdf ?
Did you give attention to the timing?
Picbuster

Hi P,
I have the Data sheet, but could you explain more please? I think it may be something to do with timing, and missing the incoming DATA, or the DATA being held in the RX and not being cleared, before the next input.
C

 

hi C,
I try to write a program in a general way that can be later expanded as required , you are being too specific.
eg:
Send a message that can carry more data/instructions to the remote receiver.
hserout "Axyz",crlf
Using 'A' as a RXR ID sync character [ A thru Z are available]
x, y, z characters/numbers can specify the action required a the RXR end. [ a thru z, lower case, 0 thru 9]
Limit the TX rate to say 0.5 Sec, to give the RXR time to execute the command and ECHO back if commanded to do so.
Hi E,
I'm looking through your information (slowly, I'm afraid)

If you recall the Tracker programs, and GET_NEO. This is something similar, but in the Tracker programs, I don't see HSERIN or HSERGET. If I'm correct, how is the DATA received?
C.

At the RXR, use RX/serial interrupt
On Interrupt check for Overflow Errors, clear as required.
Test for the Sync Character for that particular RXR, ie: 'A' etc
If ID is valid, get the rest of the message upto the crlf code

You can then use midstr to test the message content,
If midtsr(rxd,p,n) then ' to pick off a character or group of characters
if a match, then do something.!

One of the do something characters could be an command ECHO to send an 'OK' message back to the TXR. [ or any other data msg]

E

 

If you recall the Tracker programs, and GET_NEO. This is something similar, but in the Tracker programs, I don't see HSERIN or HSERGET. If I'm correct, how is the DATA received?

hi C.
E

This is a clip from the Tracker Interrupt.
getmsg: 'read and save GPGGA msg
If PIR1.RCIF = 0 Then Goto getmsg ' keep read reading until not 0
char = RCREG ' Direct read of the RXD input buffer.
str1(rxi) = char ' save char
rxi = rxi + 1 ' inc bfr pointer
If rxi > 80 Then Goto get_neo 'msg bfr over run
If char = 0x3f Then Goto eomsg '''''''''''''''' CHANGE to 0x0A or 0x3f
Goto getmsg


This is a clip from poll loop
get_neo:
If RCSTA.OERR = 1 Then 'if over run error then flush RXD buffer
RCSTA.CREN = 0
RCSTA.CREN = 1
bytchar = RCREG 'error flush bfr
bytchar = RCREG
PIR1.RCIF = 0
Endif

sync1: 'wait for a $ start of string
cp = 0
If PIR1.RCIF = 0 Then Goto sync1
bytchar = RCREG ' direct read of RXD bfr
If bytchar <> "$" Then Goto sync1 '$'
strxd(1) = bytchar

For ix = 2 To 79
Hserin bytchar
strxd(ix) = bytchar
If bytchar = eomchar Then 'LF
Goto echo
Endif
Next ix

 

Hi E,
I've decided to adopt this method over the simpler method.
Is it possible to have a GPS and an HC-12 on the same TX/RX PINs? I'm asking this for later, but for now, only the HC-12 will be connected.
C.

 

hi C,
You cannot connect two TXD driver outputs together.
Connecting two RXD's reading inputs is OK, I often do that for monitoring.

Post a short Oshonsoft Basic program, say driving just two LED' s Red, Yellow I can check it for you.
E

 

hi C,
You cannot connect two TXD driver outputs together.
Connecting two RXD's reading inputs is OK, I often do that for monitoring.

Post a short Oshonsoft Basic program, say driving just two LED' s Red, Yellow I can check it for you.
E

Hi E,
I guessed there might be a problem with double TX/RX, and bought some 18LF6722 PICS, but I better not jump ahead, just yet.
I'll have a go at a program.
C.

 

Hi C

The pic18f45k22 has two ports...

I have a few if you want to try them..

 

Hi P,
I have the Data sheet, but could you explain more please? I think it may be something to do with timing, and missing the incoming DATA, or the DATA being held in the RX and not being cleared, before the next input.
C

The inter character timing is always an issue when radio transmitter is not using internally an output (TX) buffer.

For the MPU input do not use a poll mechanism but use interrupt instead.

example
if (RC2IF) //RX int
{
RC2IF=0;
if (RCSTA2bits.OERR) // check for overrun.
{
RCSTA2bits.CREN=0; // clear receiver
RCSTA2bits.CREN=1; // re-enable
Serial.Port2Pointer=0;
}

if (!Serial.Port2In) // do not accept more data when block received // CR
{
char Receive=RCREG2; // get byte received
if (Receive==Serial.Reset_pointer) {Serial.Port2Pointer=0;}

if (Receive==13){Serial.Port2In = On;} // set received flag
Serial.Port2String[Serial.Port2Pointer]=Receive;
if (Serial.Port2Pointer>100){Serial.Port2Pointer=0;} // flush when data won't fit anymore
Serial.Port2Pointer++;
}
}

//============ in the .H file

//------------------------------------------------------------------------------
#define On 1
#define Off 0

struct{
char Reset_pointer;
int Port2Pointer;
int Port2In;
char Port2String[100];
} Serial;
//------------------------------------------------------------------------------

Do not forget to set baud rate, enable interrupt and clear int flags.

Picbuster

 

Hi C

The pic18f45k22 has two ports...

I have a few if you want to try them..

Hi I,
Most kind.

I'll have to check why I bought the 18LF6722 PICS, in case there is something special to my project. Many PINs and many uses, it's getting mighty complicated for my brain cell.

Also I am changing to surface mount, and I wonder if your 18F45K22 are TTH type.

Thanks very much, C.

 

The inter character timing is always an issue when radio transmitter is not using internally an output (TX) buffer.

For the MPU input do not use a poll mechanism but use interrupt instead.

example
if (RC2IF) //RX int
{
RC2IF=0;
if (RCSTA2bits.OERR) // check for overrun.
{
RCSTA2bits.CREN=0; // clear receiver
RCSTA2bits.CREN=1; // re-enable
Serial.Port2Pointer=0;
}

if (!Serial.Port2In) // do not accept more data when block received // CR
{
char Receive=RCREG2; // get byte received
if (Receive==Serial.Reset_pointer) {Serial.Port2Pointer=0;}

if (Receive==13){Serial.Port2In = On;} // set received flag
Serial.Port2String[Serial.Port2Pointer]=Receive;
if (Serial.Port2Pointer>100){Serial.Port2Pointer=0;} // flush when data won't fit anymore
Serial.Port2Pointer++;
}
}

//============ in the .H file

//------------------------------------------------------------------------------
#define On 1
#define Off 0

struct{
char Reset_pointer;
int Port2Pointer;
int Port2In;
char Port2String[100];
} Serial;
//------------------------------------------------------------------------------

Do not forget to set baud rate, enable interrupt and clear int flags.

Picbuster

Hi P,
Your code looks interesting, but my system uses Oshonsoft BASIC, of the type of E's code.
Thanks a lot,
C.

 

hi C,
You cannot connect two TXD driver outputs together.
Connecting two RXD's reading inputs is OK, I often do that for monitoring.

Post a short Oshonsoft Basic program, say driving just two LED' s Red, Yellow I can check it for you.
E

Hi E,
I've made a start! Is this what you expect?
I don't think AAC allows BAS files?
C.

 

hi C,
Downloaded your files, give me a little while.
E

 

hi C,
Downloaded your files, give me a little while.
E

Hi E,
No hurry, sun's out and so is my bike.
C