Differences

This shows you the differences between the selected revision and the current version of the page.

howto:serial_connector 2012/10/07 02:26 howto:serial_connector 2017/09/06 17:34 current
Line 1: Line 1:
-I have this cable in both 7 cm and 22 cm sizes and use them for my iPod touch.  If you only need a short length (to coennct to laptop, for example), it's more convenient to use this than the longer Apple cable  I only use the longer one when coenncting to a wall adapter. These short cables also are great for travel, fit easily in a small pouch with other small accessories.  The cable diameter and coennctor ends are also very close in size and look to the Apple cable  that is, slim, not bulky.  My actual lengths are a little different than what [...] cites: measured as the the length available after being plugged in (that is, length of the white part excluding the metal plugs), my 7 cm one is 6.7 cm (2 5/8 ), while my 22 cm one is 20.3 cm (8 ).+====== How to add a serial port ====== 
 + 
 +**WARNING attaching a serial port will certainly void your warranty and could destroy your unit.** 
 + 
 +The following information applies to version B1, there is a version B2 which may or may not be the same.  J3 is the serial console connection, some units have a Jameco catalog #420355 connector installed some do not, mine did not. The Jameco catalog number for the plug end is #420267. They are .49" headers. 
 + 
 +The serial console at J3 is a logic level signal, not RS232 used by serial ports such as those on PCs. Two approaches have been used to solve this problem.  One is to use a USB serial port chip leaveing out it's RS232 converters. 
 + 
 +The other is to connect up a 3.3v-to-RS232 converter such as the [[http://www.maxim-ic.com/quick_view2.cfm/qv_pk/1780|MAX3232]].  COMPSys sells an adapter with that I.C. and supporting components on a circuit board with a DB9 connector preassembled, the [[http://www.compsys1.com/workbench/On_top_of_the_Bench/Max233_Adapter/max233_adapter.html|A232DBH3v (scroll down)]] which was used in this example. 
 + 
 +=====Using A232DBHv3 adapter===== 
 + 
 +J3 provides 3.3v (pin 1), Transmit Data (pin 2), Receive Data (pin 3) and GND (pin 4), **I found that my 25W Weller Soldering Iron would not melt the solder in the GND through-hole so I used a different point for GND**.   
 + 
 +While it would be possible to wire the A232DBH3v (or other circuit) to the pads, it is better to use a connector so that disassembly remains easy.  Since I could not locate properly sized connectors, I used 30ga soild wire such as used for wire wrapping and making board repairs and modifications to install a 2.54mm 4 pin header that mated with a connector I had on hand. This wire is easily inserted into the holes in the J3 pads once the solder is melted.  This picture shows the results, not as neat as I'd like.\\ 
 +{{:howto:dsmg600-serial1.jpg?w=120&h=90}} 
 + 
 + 
 +I then soldered the connector to the A232DBH3v and cut a hole in the back of the unit to mount the DB9 as these pictures show, inside and out.\\ 
 +{{:howto:dsmg600-serialback.jpg?w=120&h=90}} {{:howto:dsmg600-back.jpg?w=120&h=90}}\\ 
 +**WARNING if you install the connector backwards you will burn out the A232DBHv3** 
 +  
 + 
 +=====Using MAX3232 or generic chip===== 
 + 
 +If you want to build your own serial converter, you will need the following parts: 
 +  * (5) 0.1 uF resin dipped capacitors (Monroes), 16V 
 + * (1) MAX3232 IC (Maxim or generic), 3V type, 16 pin DIL 
 + * (1) Right angled RS232 male socket 
 + * (1) 10 element stripboard 
 + * (1) 16 pin chip mount 
 + * (1) Wire 
 + 
 +{{:howto:shifter-dsmg600.jpg?w=120&h=86}} 
 + 
 +^ J3 Pin          ^ Signal ^  
 +^ 1    | Power (+3.3v)                | 
 +^ 2    | Transmit Data (TX)           | 
 +^ 3    | Receive Data (RX)            | 
 +^ 4    | Ground (GND)                | 
 + 
 +=====Serial Port Settings===== 
 +^ Data  ^ Settings ^ 
 +^ Baudrate |9600  | 
 +^ Data bits |8    | 
 +^ Stop bits |1    | 
 +^ Parity |None  | 
 +^ Flow Control |None  | 
 + 
 +===== Links ===== 
 +  * [[:talk:howto:serial_connector|Talk page with user experiences]] 
 +  * [[http://dns323.kood.org/forum/t67-Serial-interface.html|Forum thread]] 
 +  *  [[http://linkstationwiki.net/index.php?title=Add_a_Serial_port_to_the_PowerPC_Linkstation|linkstationwiki.net/index.php?title=Add_a_Serial_port_to_the_PowerPC_Linkstation]] 
 +  * [[http://www.kurobox.com/mwiki/index.php/Add_Serial_Port|kurobox.com/mwiki/index.php/Add_Serial_Port]] 
 +  * [[http://forum.openwrt.org/viewtopic.php?id=4275|Discussion about serial port at openwrt.org forum]]

Personal Tools