Simple Project

MarkUK

Hi

I'm starting to plan one of my first project with you guys, and i'm wondering if anyone can give me some advice.

I would like to take the following components;

LM34 Temperature Sensor
http://www.parallax.com/product/604-00011

PING))) Ultrasonic Distance Sensor
http://www.parallax.com/product/28015

and output both the values they return to a small LCD screen

Is this quite an easy project? If so, can someone give me some pointers and advice to get started

Thanks all

Duane Degn

It's an easy project once you know what you're doing but it takes a bit to get the hang of programming.

Your project looks like a great match for the Ping object I recently posted. It allows one to calibrate the Ping sensor based on the temperature.

The Ping object I wrote/modified, includes a demo program which shows who to output data to a terminal window. If your LCD screen is the type with a serial connection, the program should be easy to modify to use with the display. The less expensive parallel LCD screens will take a bit more work to use with the object.

You'll need some way to convert the analog output of your temperature sensor to a form the Prop can read. One easy way to do this is with a chip like the MCP3208 (Parallax sells these).

MarkUK

Thanks man, i'll checkout the link

What's the smallest board available that the modules could be connected to?

Mike Green

"smallest board" ... that depends on your experience level. An Activity Board has a built-in 4-channel Analog to Digital Converter and a little breadboard area where you can construct your device without soldering. You can use a 3-wire cable to connect one of the "servo" connectors to the PING off the board if you want. You could even use another cable to connect the temperature sensor to ground, +5V, and one of the ADC inputs. Use a small serial LCD ... they're easiest to use. Parallax and others sell them.

If you want to go small, you'll have to do some soldering. A QuickStart Board would be good. You could use a QuickStart Prototype board to mount the LM34 and a header for the PING. You'll need an ADC like the MCP3208. The QuickStart Board needs a +5V power supply. Dimension Engineering sells small modules that take in voltages from +7V to well over +24V and produce +5V with a switching regulator.

Andy Lindsay (Parallax)

Here are some examples with the Propeller Activity Board programmed in Propeller C that you could use as ingredients:

Ping)))
http://learn.parallax.com/propeller-c-simple-devices/sense-distance-ping

LCD
http://learn.parallax.com/propeller-c-simple-protocols/half-duplex-serial

LM34
(Replace the potentiometer with an LM34)
http://learn.parallax.com/propeller-c-simple-circuits/measure-volts

I also wrote some LM34 test code the other day, but have not posted it on the learn site yet. Here it is:

/*
  Monitor LM34.c
  
  Displays LM34 outout voltage and temperatures in terms of degrees Fahrenheit
  and Celsius.
*/

#include "simpletools.h"                      // Library includes
#include "abvolts.h"

float volts, degF, degC;                      // Voltage/temperature variables
    
int main()                                    // Main function
{
  while(1)                                    // Main loop
  {
    volts = ad_volts(3);                      // Meausre LM34 outpout voltage
    degF = volts * 100;                       // Convert to degrees F
    degC = (degF - 32.0) * 5.0 / 9.0;         // Convert to degrees C

    print("%c", HOME);                        // Top-left home position
    print("A/D3 = %1.3f V \n", volts);        // Display volts
    print("Degrees F = %3.1f \n", degF);      // Dispaly degrees F
    print("Degrees C = %3.1f \n", degC);      // Display degrees C

    pause(200);                               // Wait 0.2 s before repeat
  }
}

hanchome

Is there a similar example for only regular propeller spin code?

Publison

hanchome wrote: »

Is there a similar example for only regular propeller spin code?

Welcome to the forums. For SPIN examples, see OBEX

http://obex.parallax.com/

Is there a certain product that you are looking for support on?