From: Cameron Brennan (email@example.com)
Thank you for your wonderful site. It was a strong influence for my purchasing an ETX 90/EC as a first scope. _________________________________________________________________________________
I have determined a candidate pinout for the RS232 port on the ETX Autostar. The Autostar appears to emulate LX200 commands, and I have been able to drive the scope directly from HyperTerminal as well as from the Sky Map software package (which I recommend for starters).
The caveat is: this pinout was found by trial-and-inference; it is unofficial and appears unsupported by Meade at this time. If you are not willing to risk frying your Autostar, don't try it! I also am not an expert in RS232 protocol, so although I can tell you what worked for me, there is every chance it is sub-optimal.
Pick up the Autostar with the display facing upwards. Looking into the 4-pin RS232 port, the pins can be numbered, L to R, as 1 to 4 respectively: (best viewed in fixed-width font)
(4-pin RS232) (8-pin to ETX) ___ ___ __| |__ ____| |____ | | |.............| | | |.............| |_1 2 3 4_| |_____________| pin 1: Autostar Receive pin 2: Autostar Transmit pin 3: [ground? appears to be connected directly to pin 4, but I leave it alone] pin 4: ground I have made a simple cable to connect to my PC-compatible laptop serial port: Autostar pin: Serial port pin: #1........................#3 (PC Transmit) #2........................#2 (PC Receive) #3........................ no connect #4........................#5 (ground)
The 4-pin jack is NOT the same size as a standard telephone RJ11/14 plug. I had to file a plug down to get it to fit. Mind that an ill-fitting plug does not get stuck in the Autostar.
It has been written of the LX200 that the scope must be aligned prior to initiating control commands, and this appears to be the case for the ETX.
HyperTerminal manages to communicate with the following settings, although others might work or might be more appropriate for flow control:
Flow Control: None
The LX200 Command Set can be found on the web.
The "Clone" function does not dump directly to HyperTerminal with these settings. It will hang the Autostar until the ETX is turned off.
May your Autostar survive, and Happy Slewing!
Mike here: Use this tip with caution. You will probably invalidate your ETX warranty. Any damage caused by following this tip is not the responsibility of the contributor, myself, nor America Online.
Subject: ETX/EC Pinout Sent: Wednesday, February 10, 1999 5:34:08 From: Dick Walters (firstname.lastname@example.org) The 4 pin plug is std 4-pin "handset" plug, which has the same pin spacing as the RJ-11. I believe this is the RJ-22.These things are pretty rare at Radio Shack, probably to keep folks from going home with the wrong plug. You can find them at some electronics supply houses. Big problem is that some crimp tools won't work. Only one I've found is the Paladin 1530, a rather pricey tool. Dick Walters
Subject: Autostar Serial Cable addendum Sent: Monday, April 5, 1999 10:29:42 From: Watkins.Reece@bis.bls.com (Reece Watkins) I successfully made the RS-232 cable for the Autostar as per the instructions on this site. I just thought I'd pass along some additional info that I discovered while constructing mine. Radio Shack sells a 25' handset cord that is nearly the color of the ETX tube. It is part# 279-286 and the color is listed as "Blue", although it looks more purple to me. USD$7.99 If you're going to use the crimp-type 9-pin connector listed in Dr. Triola's part list, make sure you get a crimp pin insertion/extraction tool as well. I've forgotten the part number, but it's in the vicinity of the hood and connector on the parts wall. It's a two-piece red and white tool about 3 inches long with metallic pushers extending past the ends. USD$2.99. Unnecessary if you use a solder-type 9-pin connector, but VERY useful for the crimp-type connector. To help with strain-relief, before you place the connector in the metal hood, tie an overhand knot in the handset cord as close as you can to the connector. Make sure the knot fits inside the hood ahead of the clamp jaws. This way, if the cord gets pulled hard, it will tighten the knot and pull it against the clamp jaws instead of yanking those small wires out of your crimp pins. Since the rubber jacket on the coiled cord is springy, this may be a tight fit inside the hood, so be patient in getting it all in there. But trust me on this one. You may wish to clip wires 2, 3, and 4 a little shorter than wire 1, as wire 1 has to be a little longer to make the crossover into pin hole #3 correctly. Make sure wire 3 isn't touching anything, but don't clip it all the way back as there may be a use for it we don't know yet. Don't strip the end. Save your extra crimp pins ( you get about 11 in the package.) Radio Shack's handset cords' wires are NOT color-coded. (well, mine weren't, anyway) If you do not have a multimeter/continuity tester, pick up a little 1.5-volt wired lightbulb (USD$1.19) when you get your parts, and MAKE SURE you are wiring the right wire to the right pin. Remember, Cameron's diagram is for the Autostar SOCKET, and orient your thinking accordingly, i.e., remember to test the plug with the gold pins facing the floor instead of the ceiling when you are numbering your wires. The cable is very easy to make, even if you aren't handy with a soldering iron. It took me all of about 15 minutes, most of which was double checking the continuity of the wires with my little light bulb. The trickiest parts were stripping the little wires and getting the strain-relief knot into the hood, but that's just manual dexterity. I completely assembled mine in my lap on the couch watching TV last night with just a pair of wirecutters, a screwdriver, and a pair of needlenose pliers to crimp the pins onto the wires. SkyChart III 3.1 (www.southernstars.com) works OK with the cable, if you choose the LX200 mode. However, I could not get it to send commands to the ETX--rather, it would display the RA and Dec of the scope and update the screen to show where the ETX was supposed to be pointed. I believe it may have something to do with how my COM port was configured, I believe I had it set to Hardware flow control, which obviously this cable isn't set up for, now that I think about it. Haven't tried SkyMap 5 yet. I didn't have a lot of time to play with it last night, but it sure looks promising. Standard disclaimers apply, hope this helps other electronically-challenged people like myself! Reece Watkins
I've confirmed that SkyChart III 3.1 is only read-compatible with the Autostar. It can read the Autostar's coordinates just fine and plot the scope's position on the chart screen, but cannot send the right commands back to the telescope to slew it remotely. You must slew and/or GoTo with the handbox. It appears that SkyMap Pro 5 Demo/Full is the only software that will correctly operate the Autostar at this time.
Subject: Simple autostar cable solution. Sent: Monday, May 17, 1999 11:47:58 From: email@example.com (Walter Warren) Here's an easier way to make a cable to connect the Autostar to a computer that requires only a screwdriver with no cutting nor soldering. My solution is a standard unmodified handset cord with an adapter to connect it to the computer's serial port. Cost was $2.99 + tax and took about 5 minutes after acquiring the parts. I saw a part in a Data Comm Warehouse catalog (www.warehouse.com) for $6.99 that was a DB9 (female) to RJ12 adapter (part number 0373-3). The price was $6.99 but S/H was expensive. After a couple of calls to local electronic parts stores I found one for $2.99. Sorry, I don't have a part number, the pieces just came in a small zip-loc baggie. There were 4 pieces (2 halves of a plastic shell, a DB9 female connector, and a RJ12 jack.) and assembly screws. Wires were already attached to the RJ12 end with the DB9 "pins" attached at the other end. I simply snapped the pins into the appropriate holes on the DB9 connector (as detailed elsewhere by others) and screwed the two halves of the adapter together to complete the job. IMPORTANT: The RJ12 is 6 wire instead of 4. You have to ignore the outermost wire on each side and only consider the inner 4 wires. I clipped off the extra 2 wires to avoid confusion and conserve space inside the shell. Also, because the handset cord you'll be using is wired straight through, the RJ12 pins will be numbered reverse of the autostar pins. The leftmost pin on the autostar corresponds to the rightmost pin (again, ignoring the extra pins) of the adapter's RJ12. If your computer serial port uses a 25 pin connector instead of 9 pin, there is also an adapter available for that. I don't know if the pin configuration will be the same. As for the cable itself: The RJ12 jack is the same size as a standard RJ11 telephone plug, which of course is a little bigger than a handset plug. A handset plug fits perfectly in the Autostar. In the adapter, a handset plug fits securely, but sits a little cockeyed in the larger hole. With the adapter assembled you just plug a standard handset cord into the adapter and the autostar. There's no need to buy a special handset cord. For occasional use, just unplug one from a standard phone you already have. Walter Warren
Subject: Homemade Autostar Cable Sent: Monday, May 31, 1999 23:36:14 From: LooneyRoo@aol.com well, i fiddled with the damn cord for about 4 hours before i noticed that i had the entire setup all backwards!! the diagram on your site shows the connection as it would be if you were looking inside of the autostar port... i did not take into account for the fact that it would be completely opposite on the cable... i think you tried to explain that to me when you told me to switch the 2nd and 3rd cable, but i just didn't understand.... but now i got it!!. it took about 30 minutes to upload the software and i did a rough polar alignment outside and had great results with the 1.1m... so thank you for your help and for those who contributed to the site!!! ~noah p.s. - for those out there who are leery about making your own cable because you are afraid of frying your equipment... don't worry, because i tried every pin combination and my scope and autostar are still ticking!!! (not that this is in any way a guarantee from meade, mike or myself) -- but if you follow the directions posted on the site, you should be fine.Added later:
i have what will hopefully be my final "autostar update" question... as i said in my last post, i successfully downloaded version 1.1m and it worked perfectly. my next adventure has been to upload the other two elements that the meade download page is offering (comets and bright minor planets)... i have downloaded these two files in the "text only" format, but when i open my "autostar update" program, the only option is to upload version 1.1m... there are other spaces available, but they seem to be unavailable. i'm sure that the files were copied to the autostar update program, so that's not it. hopefully you can give me an idea as to what the problem is. thanks again!
Subject: Auto Star Uplink cable Sent: Tuesday, June 1, 1999 21:37:28 From: firstname.lastname@example.org (Donald L Phipps) I came up with another inexpensive "homebrew" cable, using a telephone handset cord with one connector removed, 3 small wire pins, and the left over PC connector to Serial connector from a new mouse. I followed the pin-out schematic described by Cameron Brennan, after identifying the pin-out for the adapter. The assembly process was about 10 minutes, and it worked the first time I tried it. I had an electronic formated drawing of the setup, but the system crashed before I could save it. I will re-do the drawing and description of each piece later this week if possible and send it to you via e-mail, so that you may share it with others. Total cost to me was $4.80 for the cord and 25 minutes total time identifying the pin--out and soldering the pins to the wires. This is much easier than trying to locate the RS-232 to 4 wire Rj-12 or 14 jack. adapter. Happy sky watching! Don Phipps ************************************************************************* Thou wilt keep him in perfect peace whose mind is stayed on Thee, because he trusteth in thee.
Subject: AutoStar cable Using PC Mouse Serial Port adapter Sent: Wednesday, June 2, 1999 7:47:11 From: Donald.Phipps@kp.org (Donald Phipps) I have had my ETX since Jan 1, 99 and love using it quite often. I purchased the Autostar two weeks ago, and wanted to be able to update it by uploading the files from the internet to my PC and then to the Autostar. The cable setup illustrated below, took about 20 minutes to put together (verifying the pin-out and creating the wire pins to plug into the mouse serial connector. When completed, the pins were insulated with electrical tape, and a protective boot of black electrical tape finished the connector. The complete setup cost less than $5 to build from components in my "Ham junk box". Here is a drawing. It is fairly simplistic, but I trust it will be helpful to some. Regards, Donald L. Phipps -- ARS: KH6LO
Subject: Autostar Cable Info update Sent: Tuesday, June 22, 1999 18:27:14 From: email@example.com (Charles E. Burton) Cameron Brennan's (firstname.lastname@example.org), Brian Nakata's (email@example.com), Reese Watkins (Watkins.Reece@bis.bls.com), and Dr. Marc Triola's (firstname.lastname@example.org) instructions on building a cable from the computer to the Autostar was very helpful. I have a few of updates that I would like to make. First, let me point out that I am an electrical engineer and have had much experience in building computer cables. Generally, cable connections come in pairs (signal and return/ground). The signal wires are usually wrapped (either shielded with a ground sheath, like a coax cable, or are twisted with the ground wire). These configurations help reduce noise pickup by the signal wires. However, that is not true of ribbon cables, like the telephone cables (RJ11 and RJ12) that are discussed in many of the articles. If you cut open the Radio Shack handset cable, you will find a red, a black, and two white wires. I would suspect that the red and black wires are for audio signal in and audio signal out and that the two white wires are used as the return/ground wires. The red and black wires are attached to pins #4 and #1, respectively, being separated by the two white (ground wires). The separation by the ground wires is to reduce crosstalk between the incoming and outgoing signals. Now to the Autostar pinouts, since #4 is connected to ground and because the impedance difference between #4 and #3 is very, very low (almost 0 ohms), it is my opinion that pins #3 and #4 should be tied together and connected to DB9 #5, because they are the return/ground wires for the two signal wires (#1 and #2). However, the way it has been suggested to wire the DB9 will work since the ground return for both #1 and #2 will be done by #4. For the digital signals that move over #1 and #2, isolation of the signal returns/grounds is not important, so you can wire it either way and everything will work. My second point has to do with a DB25 connector, rather than a DB9. My connection had to be done with a DB25 connector, and I assume others will have the same problem. I could have wired things up as suggested, but would have to add a DB9F-to-DB25F adapter. Instead, I chose to directly wire to a DB25 male connector instead. For those of you that need a DB25 connector, instead of a DB9 connector, I offer the following (using Cameron's drawings): Autostar base (4-pin RS232) (8-pin to ETX) ___ ___ __| |__ ____| |____ | | |.............| | | |.............| |_1 2 3 4_| |_____________| pin 1: Autostar Receive pin 2: Autostar Transmit pin 3: ground pin 4: ground Autostar DB9 Serial DB25 Serial pin: port pin: port pin: #1....(PC Transmit)......#3......................#2 #2....(PC Receive).......#2......................#3 #3....(ground)...........#5......................#7 #4....(ground)...........#5......................#7 Thus, we see that the DB25 transmit and receive pins are reversed from the DB9 layout and that pin 7 is the ground pin, instead of pin 5. Finally, since the cloning cable attaches between two Autostars, you need a handset null modem cable (swaps signal and ground pairs): Autostar 1 Autostar 2 pin: pin: #1.......................#2 #2.......................#1 #3.......................#4 #4.......................#3 To build the null modem cable, you can use a handset cable, cut off one connector, and crimp on a new handset plug (after reversing the appropriate wires). I would expect Radio Shack to have all of the needed parts. Don't mix up #2 and #3 (the white wires), because you might burn out the Autostar transmitter on one of the Autostars. Either end of the cable can be plugged into either Autostar. The cable wiring takes care of the magic. Disclaimer: Use these suggestions at your own risk. Any damage caused by following these tips is not my responsibility or that of my ISP or my employer or anyone else, for that matter. You take responsibility for you own actions. Happy downloading, Chuck Burton P.S. Thanks for the great ETX site, Mike.
Subject: Autostar Information ... Sent: Thursday, November 9, 2000 08:55:57 From: email@example.com (Jon Swarner) I am writing this to add to Walter Warren's post concerning the control cable for the Autostar. I also found the part that he used at a local retailer in Atlanta, ACK Electronics. They also do mail orders. They have two locations; Atlanta (800) 282-7954, and Birmingham (800) 338-4218. They also have a website at www.acksupply.com. The part number for the adapter is: 40-9526F AIM. It costs $2.97. To overcome the wobbly plug from the handset cord, I also got a 6 pin RJ-12 plug (part number 30-9915 GC; $0.69). I was able to "crimp" it using a jewler's screwdriver to press the pins in, eliminating the need for an expensive crimping tool. To use the Adapter from Ack, simply connect the yellow wire in the adapter to pin 3, the green wire to pin 2, and the black wire to pin 5. You can cut the red, blue and white wires if desired for more room. The whole assembly (adapter and cable) took about 5 minutes, including determining the pin-out. I am using it with Skymap Pro version 7 (demo) and it works like a charm! Thank you for the great site! Jonathan Swarner
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