My Spanish is close to non-existent, but I think I understood a word or two of what you said.
Yes, the info on that page is basically on the Maxxim MAX232 (US Integrated Circuit manufacturer, mostly providing interface IC's, amplifiers and smaller D/A and A/D converters on a world wide scale) and the connector pins used to connect it when used for the above said cable.
The MAX232C is an old-timer. You need a voltage level converter for the cable, hence this circuit has been shown as a "cable wiring diagram". Anything 5V CMOS to RS-232 voltage levels will probably do, not only the MAX232C.
If you have any questions regarding your N90, feel free to post these questions in the Nikon products/Nikon bodies forum. If you post in Spanish, please be so kind and prefix the subject with "In Spanish:".
First of all, the TTL/CMOS output at pin 9 (R2out) is left open (not connected). That is ok since the input at pin 8 is unused. The RS-232C level output at pin 14 (T1out) can also be left open since the input for this driver at pin 11 is also left unused.
The schematics shows pin 8 and 11 grounded. This is not a good idea since it increase power consumption (though only minimal) amongst others. The better way is to use a resistor between an input and ground, a so called "pull-down resistor".
I would then recommend the following minor change to the said schematic:
Connect a 10KOhm resistor between pin 8 and ground. Connect a 10KOhm resistor between pin 11 and ground.
The "curly braces" which are located at both sides of the circuit are NOT clamps! Do NOT connect the pins 11+10, 12+9, 13+8 nor 14+7 together. The curly braces only indicates the type of input and output of the circuit, i.e. "TTL/CMOS INPUT" etc.
The pin 10 at the connector can be seen in the PDF file at the linked site mentioned in the first postings in this thread. Just make sure you zoom in enough to be able to read the pin numbers.
Ok, Ok. I can try to write in english with the help of one dictionary.
The 10 pin connector for the F90 isn’t a problem. It is very easy to make.
The home-made connector: 1- We need 10 piece of fine wire of telephonic cable, with its cover. 2- Clean about ½ centimetres of each one of the cables. 3- Place 2 or 3 layers of transparent plastic (of shopping bag for example) over the female connector of the camera. It must be transparent for see the holes of the connector. 4- Pierce the plastic with each one of the cables in the holes of the female connector in the camera. The pins 2 and 9 isn’t necessary for the MC-31 and the remote shutter release cable. 5- With one pistol of thermal-glue “in bars” (about 5 US$) We have extend the glue over the connection but not much glue .... It is very hot. All the cables must be fasten for the glue. 6- Leave until it cools down ... about 5 minutes. 7- We must make a mark in the connector for remember the position of this. 8- Remove the connector of the camera and for reinforce the connector, we have extend a little of thermal-glue over and to wrap with electric strip.
It is the way for make your own 10 pin connector easily.
In this moment I work with one of this “invents” for the remote shutter release cable and it work fine. If someone want the plan for make one, I can send to he.
My problem with the chip is the connections 9 and 14 of the CHIP 232. In the diagram this numbers haven’t connection. And the number 9 is in the same parenthesis with the connection number 12 in the CHIP. I have purchase the MAX 232C because in the shop of electronic components only has this.
This weekend I test without the connectios 9 and 14 in the chip and if it work fine, I inform for all you. And I can take a photos with a digital camera and send the result.
Greetings from Spain, and thanks for help me. Roberto
La verdad es que no creo que nadie pueda criticar tu capacidad de comunicación en inglés. Tal vez has sido demasiado modesto en ello.
En todo caso, la solución para construír el conector me parece absolutamente impecable. Te felicito por que es una idea muy creativa. Efectivamente entonces, entiendo que el condenado conector es muy difícil de conseguir ?
Respecto al problema de conectividad, dado que yo no soy tan técnico en estas materias, se lo he entregado a la gente de ingeniería que trabaja conmigo para que me den una respuesta. Seguramente eso complementará tu prueba del fin de semana.
Saludos Jorge A. P.D. No te has incorporado con tu perfil aún ??
Your message is absolutely understandable, no problems at all I would recommend the following additions to the "making of the MC-31 cable":
1. Place the MAX232C as close as possible to the camera. This should be done since the voltage signal level of the camera is pretty low. By placing the circuit close to the camera, you will have less problems (noise) in the signal path.
2. Do not insert the male connector into the camera when you are making the cable. Reason: You do not want to heat up the female connector in the camera when you're soldering the wires onto the connector since this may cause damage to the connector internally. A better way is to get a male connector, clamp it onto your work table, insert the female connector into it and then solder the wires onto the connector. Or, clamp the male connector directly to your work table, but be careful as not to bend the sensitive pins!
3. If you're using a cable of more than let's say 3,0m of length, I would recommend a shielded cable to reduce interference/noise. You would then solder each side of the shield to the shield of each connector (the mini-DIN at the camera and the mini-SUB on the PC side). The maximum length of the cable is in direct relation to the RS-232 signal levels. With the recommended 1.0uF resp. 0.1uF in the schematic, you should probably not go over 2,0m!
I would then recommend you to use at least 10uF tantalum capacitors. The 1.0uF in the schematic is a poor mans construction IMO. Reason: the capacitors are the so called "charge pumps" and their capacitance is in direct relation to the voltage level on the RS-232C side. With 1.0uF you will be far away from the specified +-12V RS-232C specification - you will rather probably have something like the +-5...6V. With 10uF you would have something like +-10V
The connetions it´s OK. The MAX 232 is about 5 cm near of the camera. The cable have about 1,5 meters. The capacitors are 1.0uF. In de pins 8 and 11 of MAX 232, I have place a resistor between this pins and ground (Recommended by Bo). I have used the PC Com Port of 9 pin conectors. (Pin 3 for transmitted, Pin 2 for Recived and Pin 5 for Ground).
But the programs (optn90s and others) don’t see the camera.
Does anyone help me? Have anyone make his own MC-31 and work fine?
¿Que tal Jorge? Vamos a practicar un poco el ingles.
I have try with the programs are the OPTN90S (for DOS) and SOFTALK (by COCOON for Windows).
I send a message to the inventors of the circuit and Ken Hancock answer me with this e-mail: ----------------------------------------------------------- > Does anyone help me? > Have anyone make his own MC-31 and work fine?
Yes, other people have been successful in making this cable. Best thing to do is on your PC use optn90s and check the voltages as optn90s queries the camera and make sure the voltages are in the RS-232 range. If you didn't use the Maxim part number, but used another CMOS to RS-232 converter, you might need a pull-up resistor. Here's a tip I received from someone else.
----- 3. F90X and N90S seems to use an open collector output on PIN 5. This leaves a success of the project to the judgment of internal pull-up resistor inside MAX232 or 233 (which is way too high, especially on Analog devices clones: ADM232 and ADM233) making overall schematic susceptible to camera batteries voltage level and RF interference. E.g. when measuring "high" level of F90x output I got only 3V with MAX232 connected and less then 1V with ADM233. Of course the latter refused to work. The solution was to put a 3-10KOhm resistor between pins 5 and 3 of F90x in either case. This makes a high logic level a clean and nice 5V. Would it be reasonable to put it into your original schematic as a fool-proof design? -----
a very dumb question: You do have 5 volts applied on the MAX232C for power supply do you?
As it seems that the output of the N90 is an Open Collector (O/C) output, you must use pull-up resistors as mentioned in that email. 10KOhm is fine.
Also, a very late warning: the MAX232C is ESD (electro-statical discharge) sensitive. Not very sensitive, but one can destroy it by not being grounded and fumbling (touching) the pins of the IC or using a Weller solder station (or similar brand) with the bi-metal temperature control (the solder pen clicks on and off to regulate the tip temperature. By this it may destroy the IC if the tip of the pen is not grounded).
Hi Bo: One question.... Ken Hancock in his message, he said something about putting a 3-10 KOhm resistor between pins 5 and 3 of the camera. I'm not absolutely sure of this thing.
Pin 5 is current and pin 3 is data: do I have to put the resistor between these two lines?, or, do I have to put the resistor between pin 5 of the camera and pin 10 of the MAX 232c, and another one between pin 3 of the camera and pin 2 of the MAX 232c?.
Regarding the 10pin mini-DIN male connector: Not much of any help, but any well assorted electronics store should have it. It is a pretty common connector. I only have 8 and 5 pin mini-DIN connectors here, so I can't send you one
I´m sorry for the delay ... you know ... the summer .
About your question: did your homemade device worked ?? No, this damned cable don´t work . I have change the MAX232, but this is not the problem. I have repeat all the electronic circuit, but doesn´t work either. I´m very unhappy about this theme .
If we all are not all screwed up on this theme, i.e. the Camera is indeed only using TTL/CMOS voltage levels (which I am quite sure about), then they probably are using a SMD version of the IC. For a MAX232 SMD equivalent, the circuit is very small, some 8mmm long and some 4mm wide - you can hide it in a connector. Same goes for SMD tantalum capacitors - small to very small in size.
As RAMBO say: My God, Colonel Thruman ... I don´t sense the legs .
I think all the problem "for me", is that I don´t speak with someone who have make his own connection cable, and then, he comment with us abuot the "errors" in the construction and of course about my owns "ERRORS".
I will go, with the "planes" and ours deliberations, to one frined of mine that he is Enginner in Telecommunications and then to see if he know where I have put one´s foot in it.
Hehe. All fine here. The message popped up very high up in the listings of this forum since we transfered it from the other forum, no longer existing.
Sounds great! Should you ever feel the urge to help other Nikonians with a schematic drawing incl. comments on how-to-do your own MC-31, please just let me know. I am sure it would interest others as well.