Difference between revisions of "Serial cable with TTL voltage level converter"
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=Background= | |||
The Serial port on your computer uses voltages from -3 to -25V to transmit a logic "1" and a voltage from +3 to +25V to transmit a logic "0" as defined for the RS232 standard. On most PCs these signals swing from -13 to +13V. | The Serial port on your computer uses voltages from -3 to -25V to transmit a logic "1" and a voltage from +3 to +25V to transmit a logic "0" as defined for the RS232 standard. On most PCs these signals swing from -13 to +13V. | ||
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So in order to connect a Merlin/Orion/Skywatcher remote head to a computer you need a voltage level converter between the two devices that not only inverts the voltages for digital "1" and "0" but also uses different voltage levels. | So in order to connect a Merlin/Orion/Skywatcher remote head to a computer you need a voltage level converter between the two devices that not only inverts the voltages for digital "1" and "0" but also uses different voltage levels. | ||
Tronisoft sold these converters but now lists them all as "out of stock": | =Solutions= | ||
Unfortunately there is no off-the-shelf solution available so you need to do a bit of manual soldering | |||
Tronisoft sold these converters for some time but now lists them all as "out of stock": | |||
http://www.tronisoft.com/cat_rs232tottl.php | http://www.tronisoft.com/cat_rs232tottl.php | ||
and cable creation guide: http://www.autopano.net/wiki-fr/images-fr/5/57/CONNECTING_THE_%C2%AB%C2%A0CABLE-CONNECTOR%C2%A0%C2%BB_TO_THE_TRONISOFT_4207.pdf | |||
Other untested options are: | |||
* http://www.amazon.co.uk/TRIXES-USB-Serial-Converter-CP2102/dp/B004ROOPK6/ref=pd_sim_sbs_ce_1 | |||
* http://www.amazon.co.uk/USB-Converter-Module-Built-CP2102/dp/B008RF73CS/ref=pd_sim_sbs_ce_3 | |||
* http://www.amazon.co.uk/USB-Serial-TTL-Cable-FTDI/dp/B00514ZCHQ | |||
=Bluetooth Interfaces= | |||
There are several wireless solutions that connect computer and Merlin/Orion/Skywatcher remote head via bluetooth (like: http://www.ursaminor.hu/). These should work fine with Chronomotion as long as the bluetooth connection acts as a virtual serial interface. Chronomotion has not been officially tested with such bluetooth devices yet but we are very interested in reports of someone who tried. | |||
Revision as of 13:03, 28 March 2013
1 Background
The Serial port on your computer uses voltages from -3 to -25V to transmit a logic "1" and a voltage from +3 to +25V to transmit a logic "0" as defined for the RS232 standard. On most PCs these signals swing from -13 to +13V.
The Merlin/Orion/Skywatcher remote head requires different voltages (called TTL levels) that are 0V (digital "0") and 5V (digital "1").
| RS232 | TTL | |
|---|---|---|
| digtial "1" | -25V to -3V | 5V |
| digital "0" | +3V to +25V | 0V |
So in order to connect a Merlin/Orion/Skywatcher remote head to a computer you need a voltage level converter between the two devices that not only inverts the voltages for digital "1" and "0" but also uses different voltage levels.
2 Solutions
Unfortunately there is no off-the-shelf solution available so you need to do a bit of manual soldering
Tronisoft sold these converters for some time but now lists them all as "out of stock":
http://www.tronisoft.com/cat_rs232tottl.php
and cable creation guide: http://www.autopano.net/wiki-fr/images-fr/5/57/CONNECTING_THE_%C2%AB%C2%A0CABLE-CONNECTOR%C2%A0%C2%BB_TO_THE_TRONISOFT_4207.pdf
Other untested options are:
- http://www.amazon.co.uk/TRIXES-USB-Serial-Converter-CP2102/dp/B004ROOPK6/ref=pd_sim_sbs_ce_1
- http://www.amazon.co.uk/USB-Converter-Module-Built-CP2102/dp/B008RF73CS/ref=pd_sim_sbs_ce_3
- http://www.amazon.co.uk/USB-Serial-TTL-Cable-FTDI/dp/B00514ZCHQ
3 Bluetooth Interfaces
There are several wireless solutions that connect computer and Merlin/Orion/Skywatcher remote head via bluetooth (like: http://www.ursaminor.hu/). These should work fine with Chronomotion as long as the bluetooth connection acts as a virtual serial interface. Chronomotion has not been officially tested with such bluetooth devices yet but we are very interested in reports of someone who tried.