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--- guides:linkingarduinotontx2 [2013/05/16 18:24] – upu
+++ guides:linkingarduinotontx2 [2016/10/21 21:57] (current) – upu
@@ Line 1: / Line 1: @@
-========Linking an Arduino to a Radiometrix NTX2 Transmitter ========
+========Linking an Arduino to a Radiometrix NTX2B Transmitter ========
 ===== Part 1 - Test Circuit and Test Code =====
@@ Line 11: / Line 11: @@
 **This may be the first bit of code you've come across with regards to creating a tracker. There is always the tempation to cut and paste it and away you go. And in isolation this may work. However should you then cut and paste further code without understanding what is going you will end up with an unworkable mess and something that is next to impossible for us to assist you with. Pretty please take the time to work out what the code below is doing, redo it yourself, break it, fix it most importantly __understand__ it. **
-In this short tutorial I’ll give a step by step instructions on connecting a [[http://www.radiometrix.co.uk|Radiometrix NTX2]] to an Arduino and getting it to shift its transmission between two frequencies slightly giving two tones. In the second part I’ll demonstrate how to control this and use the circuit to transmit data at 50 or 300 baud using [[http://en.wikipedia.org/wiki/Radioteletype|RTTY]].
+In this short tutorial I’ll give a step by step instructions on connecting a [[https://store.uputronics.com/index.php?route=product/product&path=61&product_id=60|Radiometrix NTX2B]] to an Arduino and getting it to shift its transmission between two frequencies slightly giving two tones. In the second part I’ll demonstrate how to control this and use the circuit to transmit data at 50 or 300 baud using [[http://en.wikipedia.org/wiki/Radioteletype|RTTY]].
-The theory is as follows: you adjust the voltage on the NTX2's TXD pin which adjusts its transmission frequency slightly. The difference in this frequency is called the shift. By doing this in a controlled fashion you can transmit 1's and 0's and therefore data. There are a number of methods to adjusting the voltage, connecting the TXD to a PWM on the Arduino, using a DAC or the most simple method discussed here using a voltage divider.
+The theory is as follows: you adjust the voltage on the NTX2B's TXD pin which adjusts its transmission frequency slightly. The difference in this frequency is called the shift. By doing this in a controlled fashion you can transmit 1's and 0's and therefore data. There are a number of methods to adjusting the voltage, connecting the TXD to a PWM on the Arduino, using a DAC or the most simple method discussed here using a voltage divider.
-The NTX2 is a FM (Frequency Modulation) module intended to have a voltage applied to the TXD pin of between 0 and 3 volts. This voltage range changes the output frequency of the module by up to 6KHz. This means for each 1Hz change in frequency you need to change the voltage by 0.0005v (3 divided 6000) so to get a shift of 500hz you need to toggle the voltage applied to the TXD pin by 500x0.0005=0.25v.
+The NTX2B is a FM (Frequency Modulation) module intended to have a voltage applied to the TXD pin of between 0 and 3 volts. This voltage range changes the output frequency of the module by up to 6KHz. This means for each 1Hz change in frequency you need to change the voltage by 0.0005v (3 divided 6000) so to get a shift of 500hz you need to toggle the voltage applied to the TXD pin by 500x0.0005=0.25v.
 Getting the shift totally accurate isn't entirely essential but it should be kept in the 300-600Hz region.
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 ==== Items Required ====
- Radiometrix NTX2 \\
+ Radiometrix NTX2B \\
  Arduino or similar microcontroller\\
 x 47k resistor (Somewhere from 40k to 50k exact value isn't critical)\\
@@ Line 84: / Line 84: @@
 </code>
-If you have used Arduino before this code will look familiar. This is because it is just the example code for Blinking the LED. In fact this will be currently blinking the LED in time to the radio changing frequency. All that is happening here is pin 13 is going from 0v (low) to 5v(high). This is reduced by the voltage divider on the NTX2's TXD pin (Note the NTX2 has an input resistor of 100k so this acts like another voltage divider in conjunction with the 47k/20k resistor).
+If you have used Arduino before this code will look familiar. This is because it is just the example code for Blinking the LED. In fact this will be currently blinking the LED in time to the radio changing frequency. All that is happening here is pin 13 is going from 0v (low) to 5v(high). This is reduced by the voltage divider on the NTX2's TXD pin (Note the NTX2 has an input resistor of 100k so this acts like another voltage divider in conjunction with the 47k/32k resistor).
 / Tune in your radio to the frequency listed on your NTX2 module (either 434.075Mhz or 434.650Mhz) ensuring you have the mode set to USB. You should hear an alternating sequence of beeps. You may need to tune up or down a little, if you can't find it  go back and check your circuit. Its most likely you'll find the transmission slighly below the frequency listed on the module.
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 ===== Where to buy the NTX2 =====
-  *[[http://ava.upuaut.net/store/index.php?route=product/category&path=71_63|HAB Supplies stock the NTX2]]
+  *[[https://store.uputronics.com/index.php?route=product/product&path=61&product_id=60|Uputronics stock the NTX2B]]
-  *[[http://uk.farnell.com/radiometrix/ntx2-434-650-10/transmitter-434-65mhz-10mw/dp/1348829|Farnell(UK)]] - expensive
 ===== Acknowledgements =====
-Thanks to Rob Harrison for the RTTY code and to Dave Akerman for suggesting a more sensible one pin circuit to drive the NTX2.
+Thanks to Rob Harrison for the RTTY code and to Dave Akerman for suggesting a more sensible one pin circuit to drive the NTX2B.
 Article authored by Anthony Stirk.
 Additional amendments by Keval, lz1dev, Costyn, Jcoxon.