Radar Speed display using the HB100 Module

[Jaden]

Hi, I know there is Arduino projects out there for this but I am more comfortable using the picaxe. Can someone direct me to commands I may need to use and how to decipher what is coming out of the HB100 module? I will have it driving a large two digit seven segment display. Is the picaxe fast enough? Once I find out how to look at what the HB100 is putting out I should be able to stumble through the rest

Thanks

 

[papaof2]

From the spec sheet at https://www.smart-prototyping.com/image/data/2020/10/102077 - HB100 Dupler Module/HB100_Microwave_Sensor_Application_Note.pdf
For objects moving directly to/from the HB100 the formula for the Doppler frequency (Fd) is
Fd = 19.49V (Velocity in km/hour) or 31.36V (V in mile per hour)
Basically, you need the amplifier shown in the App Note and use the PICAXE as an audio frequency meter. Then divide the measured audio frequency by 19.49 (km/hr) or 31.36 (mi/hr) and send it to a display. Division is NOT one of the fastest operations on the PICAXE so I have no idea how well this would work - you're on your own with that.

 

[hippy]

You can determine the frequency from the pulse time of the signal : f = 1/t
Then you can determine the speed : kph = f/19.49, mph = f/31.36
Which is : kph = 1/(t *19.49), mph = 1/(t*31.36)

That's quite tricky to calculate on a PICAXE, so reading the actual frequency with COUNT may give a better and higher resolution result -

kph = f/19.49 = f * (1/19.49) = f * 0.05131
mph = f/31.36 = f * (1/31.36) = f * 0.03189

But COUNT takes some time to execute, so calculating 'f' from 't' and then using that maths would probably be the optimum solution.

 

[PhilHornby]

A fascinating little device - I'm sure I can find a use for such a thing

However ...

All the modules I can find, are described as using 10.525GHz.

The Datasheet / Application Note I found, has a chart showing 10.525GHz as being for the USA/Belgium/Netherlands :-



Has anyone spotted any 10.587 or 10.687 GHz variants for the UK?

(RS seems to have had something similar in the past, but they're discontinued.)