http://www.picaxeforum.co.uk/showthread.php?21460-ASCII-test-generator&highlight=ascii
Correct title ASCII Test Generator - sorry Ray.
I have been playing with Ray Burnette's Picaxe 08M2 Quick Brown Fox Generator. Thank you Ray.
I have modified the codet to send a callsign ident with a serial number and a replacement short fixed length message – Not the QBF one of course. Tinkered with in the well established tradition of the forum.
The purpose of the device is ultimately to key up and send a beacon from an Amaterur Radio trancseiver. The purpose being to activate a cross band talk through unit from a mobile vehicle for transmission coverage testing purposes.
Picaxe 08M2 Pin C.1 goes high to operate an LED during breadboard testing or the input to an opto isolator, with current limiting resistor, naturally. The output of the opto isolator will pull down the PTT line of the transceiver, prior to, during and shortly after the message transmission interval.
During the breadboard testing period using the PE Monitor I am using an inverted data signal, but wish ultimately to key an AFSK oscillator, which I had hoped to implement using a second 08M2 Picaxe chip to provide appropriate 2125Hz and 2295Hz, 2550Hz or 2975Hz tones depending on the shift required for the final device.
An alternate option is to either use Morse or a combination of Morse and (ASCII, or ITA2) telegraph data permitting automated or manual assets to monitor the progress.
Through the auspices of the PE and HSERSETUP and HSEROUT, in lieu of SEROUT, I have the telegraph speed down to 300 Baud
HSERSETUP 3332, %10010
, with every prospect of being able to take it down to 50 Baud
HSERSETUP 1999, %10010
I was hoping to key the output data and a mode line to an 08M2 running at 32MHz(?) to generate
pwmout pwmdiv16, 2, 234, 471 ; 2125Hz Mark tone
pwmout pwmdiv16, 2, 167, 336 ; 2975Hz Space tone
or
pwmout pwmdiv16, 2, 103, 208 ; 600Hz MCW tone
pwmout 2, off
The MCW option is OK, but two tone keying has phase discontinuity that is audible when the tones change, some transitions being more noticeable than others. I may get away with a dirty telegraph signal at 50 baud with a bit of filtering, but does anyone have any good ideas of how I might synchronise the change over of the pwmout signals even if it means a 'very slight' distortion of the telegraph elements?
Modified code and a quick diagram is about a week away, but you can have snippets if you wish.
Correct title ASCII Test Generator - sorry Ray.
I have been playing with Ray Burnette's Picaxe 08M2 Quick Brown Fox Generator. Thank you Ray.
I have modified the codet to send a callsign ident with a serial number and a replacement short fixed length message – Not the QBF one of course. Tinkered with in the well established tradition of the forum.
The purpose of the device is ultimately to key up and send a beacon from an Amaterur Radio trancseiver. The purpose being to activate a cross band talk through unit from a mobile vehicle for transmission coverage testing purposes.
Picaxe 08M2 Pin C.1 goes high to operate an LED during breadboard testing or the input to an opto isolator, with current limiting resistor, naturally. The output of the opto isolator will pull down the PTT line of the transceiver, prior to, during and shortly after the message transmission interval.
During the breadboard testing period using the PE Monitor I am using an inverted data signal, but wish ultimately to key an AFSK oscillator, which I had hoped to implement using a second 08M2 Picaxe chip to provide appropriate 2125Hz and 2295Hz, 2550Hz or 2975Hz tones depending on the shift required for the final device.
An alternate option is to either use Morse or a combination of Morse and (ASCII, or ITA2) telegraph data permitting automated or manual assets to monitor the progress.
Through the auspices of the PE and HSERSETUP and HSEROUT, in lieu of SEROUT, I have the telegraph speed down to 300 Baud
HSERSETUP 3332, %10010
, with every prospect of being able to take it down to 50 Baud
HSERSETUP 1999, %10010
I was hoping to key the output data and a mode line to an 08M2 running at 32MHz(?) to generate
pwmout pwmdiv16, 2, 234, 471 ; 2125Hz Mark tone
pwmout pwmdiv16, 2, 167, 336 ; 2975Hz Space tone
or
pwmout pwmdiv16, 2, 103, 208 ; 600Hz MCW tone
pwmout 2, off
The MCW option is OK, but two tone keying has phase discontinuity that is audible when the tones change, some transitions being more noticeable than others. I may get away with a dirty telegraph signal at 50 baud with a bit of filtering, but does anyone have any good ideas of how I might synchronise the change over of the pwmout signals even if it means a 'very slight' distortion of the telegraph elements?
Modified code and a quick diagram is about a week away, but you can have snippets if you wish.
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