View Full Version : Ramsey Doppler Kit

11-20-2009, 05:17 PM
I'm new to BS and need some help.

The doppler kit is triggering 16 LED to show direction via an 74HC4515 multiplexer
How can i easily "tap" the input from this chip so that i get the 4bit data to my BS2 ?
The idea is that with the 4 input signal i can decode the direction and let the BS2 format an RS232 string so that i can receive this on a computer or an LCD display so that i don't need the LEDs.

PJ Allen
11-20-2009, 07:07 PM
Ramsey usually includes a schematic, perhaps you could scan it and attach it in your next post. Maybe there's one on the web, but I'm not going to looking for it.
Anyway, this should be pretty easy to do, but the devil is in the details (provide them.)

11-20-2009, 07:25 PM
Hmm here are part of the schematic.

I think i have to tap the signals from U7 or the input to U11

But how http://forums.parallax.com/images/smilies/smile.gif

PJ Allen
11-20-2009, 08:10 PM
Yeah, that's how, man. Either way, Q0-3 / A0-3 and GND. Use a strip of ribbon wire and run those 5 wires out and over to BS2. You could install a connector on the Ramsey box and so on.

11-22-2009, 01:28 AM
Hmm this didn't work. When the doppler unit is not scanning i get "0" on Q0-3
When i start the doppler i get values like: 0000 0001 0010 0011 etc even if it should only get one value so then it must be something to syncronise when to read the value.

PJ Allen
11-22-2009, 03:38 AM
Yes, probably that LE (Latch Enable), U11_p1.

That 4515 is the output device, 4bits in, 1 of 16 out, always Enabled, so the LE must be the cinch.

11-23-2009, 08:55 PM
Seems to work now when i'm using the "LE"

Now i have to wait x-ms to "simulate" the damping function so that the reading have stabilised it selves.

The calibrate function i'm not going to use as it's not much space on the BS2. This can be done manually moving the antenna array.

So the next project is to get this to work with www.tnc-x.com and format the result from t6he doppler unit into something that can be decoded on AX25.