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3 x 7 segment display - output speed from radar gun

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matteovinci

New Member
Ok, so i'm a little rusty but wanting to help a friend with a little project

He has purchased a radar gun & is looking to output the speed to 3 x 7 segment displays

currently it outputs ascii data:

<D> [SSS] <CR>

<D> is direction
[SSS] is the speed numeric value
<cr> at the end completing the data packet

though this can aparently be changed to other data types, hopefully hex at the very least

i know the max 6954 aparently takes ascii, though not for 7 segment displays, seems only hex still for 7 segments?

so obviously looking for a circuit that will read the output & drive the 3 displays
the less components the better

have found a few examples but would appreciate some feedback here first
 
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superfrog

New Member
if as I suspect, ascii means ascii coded data over rs232 serial, then I suspect you could find a microcontroller that supports rs232, substract '0' to to your figures comming in, converting them effectively to BCD, and use the precious data to drive 3 7 segments displays. Make that 2 pins for serial in, 2 pins for serial out if needed, 7+3 pins for the display. That should leave you a couple of pins for flashing leds, triggering buzzers, drinving lcds over Mr RB. 1 wire interface or anything else you fancy.

You will need a signal level converter for RS232, a mcu and 3 7 segments displays + 7 resistor + power supply .
I suspect you might even be able to steal power from the serial port, which provides a nice stable high when idling. I am not sure it would be quite enough to drive the seven segment display though.
 

Sceadwian

Banned
Yeah a small micro controller could drive an actual display driver chip, that'll make it about as simple as you can get.
 

matteovinci

New Member
now we have the radar output working in hex:

8n1 HEX [2][84][1][SPEED][1][AA][3]

028401 00 01AA03 - No speed Data
028401 6E 01AA03 - Speed Data 110km/h
028401 38 01AA03 - Speed Data 56km/h

(Spaces included for readability)

So the decision now comes as to what will be the best/easiest way to implement this while not having too big of a learning curve

the following was suggested from itsdisplays:

1. MCA2X16 - LED Controller
2. CB232 - Interface board
3. DRA1 - Driver board
4. Some DC power supply 8V - 24 V
5. Custom program

---

any suggestions on both the hardware & software side?
 
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