Questions regarding a project
ssdd65
Posts: 2
So I am 100% new to BASIC stamp. But, I was hoping to use this as a basic computer on a project I just recently started on. My goal: To build a simple weather balloon that will relay some basic weather information from sensors on the balloon to me on the ground via morse code.
The general principle I had in mind:
Sensor -> BASIC Stamp -> Output in Morse (long/short pulses) -> use these long/short pulses to control a tone generator (which turns on when the pulse is put in) -> tone is sent to a low power FM transmitter and sent to the ground (a 1 watt FM transmitter should do the trick and does not require any licensing)
So I was wondering:
1. Do you think this type of system is feasible?
2. What type of stamp/stamp kit would you recommend?
3. Lets say I wanted to use a LM34 temperature sensor for starters, how does one go about interfacing this to the microcontroller? (or where could I find information on how to do this?)
4. How difficult of a programming job am I looking at here if the goal is to take the input from the sensor, interpret, and output as morse code?
(I have some experience in web programming, so I'm not totally new to programming. I've also built several electronic projects in the past which may help in this project)
Thanks in advance, I'm looking forward to many fun projects with parallax products in the future,
-ssdd65
The general principle I had in mind:
Sensor -> BASIC Stamp -> Output in Morse (long/short pulses) -> use these long/short pulses to control a tone generator (which turns on when the pulse is put in) -> tone is sent to a low power FM transmitter and sent to the ground (a 1 watt FM transmitter should do the trick and does not require any licensing)
So I was wondering:
1. Do you think this type of system is feasible?
2. What type of stamp/stamp kit would you recommend?
3. Lets say I wanted to use a LM34 temperature sensor for starters, how does one go about interfacing this to the microcontroller? (or where could I find information on how to do this?)
4. How difficult of a programming job am I looking at here if the goal is to take the input from the sensor, interpret, and output as morse code?
(I have some experience in web programming, so I'm not totally new to programming. I've also built several electronic projects in the past which may help in this project)
Thanks in advance, I'm looking forward to many fun projects with parallax products in the future,
-ssdd65
Comments
2) Pretty much any Stamp board will do. The Homework Board in the Stamp Activity Kit or the Stamp Discovery Kit is more than adequate.
3) To read temperature using an LM34, you have to measure the output voltage. There's a technique using the RCTIME statement that's described in Tracy Allen's website (www.emesystems.com). Click on the "app-notes" link and look for the section on the RCTIME statement. His description is for measuring the battery voltage, but the same technique works for the LM34.
4) The Stamp has a statement (FREQOUT) for outputting tones and you can specify the duration of the tone. See the documentation on the FREQOUT statement for details including the simple resistor/capacitor low-pass filter that you will need. The resulting signal could be sent to the FM transmitter.
It's pretty easy to send Morse code using a Stamp. There may already be sample code. What you'll need is a table of Morse code stored in the EEPROM using DATA statements, one byte per character with the characters encoded in the table. You read the table with READ statements. A zero bit would be a short tone and a one bit would be a long tone. A one bit followed by all zeros would mark the end of the character. An "A" for example would be %01100000. An "N" would be %10100000. You'd test the high order bit of the byte, generate the tone, and shift the value left by 1 bit. When the byte is %10000000, you're done and you generate a space, then go process the next character.
Sounds like a fun project!
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Ken Gracey
Parallax Inc.
Follow me at http://twitter.com/ParallaxKen for some insider news.
Post Edited (Ken Gracey (Parallax)) : 7/27/2010 5:05:37 AM GMT
Ken, thanks for pointing out that documentation on the bottom of the page, I never would have found that otherwise.
Its also good to know that the stamps can output a frequency directly as this simplifies the system many times over (and makes it lighter for flying!)
I will likely start with a kit which I'll have to invest in next time I have a few dollars laying around.
Hopefully not too long into the future I will be able to post back with progress...
-ssdd65