I BTW use for ALT encoder an S6 Inclinometer instead of standard encoder. It is held in place and is still there after 1 year. It requires no special mounting and no modifacation to a factory made DOB.
Excellent. Just ordered parts from jameco and farcircuits. Just waiting for u's digital to open.
Next question... How do you guys power your box. Is a 9v battery sufficient for a few long nights.
9V batteries are known to be of low capacity..
Ek's box doesn't use much, but encoders, yes they do - 20 ~50mA each.
This is too much for 9V battery to last couple of nights.. more likely couple of hours. http://data.energizer.com/PDFs/522.pdf
Such prompt replies! Thanks. I was thinking of going USB but I thought the ek's box might be iPhone compatible in the future so I stuck to serial. And I'm thinking of buying a cheap <$10 palm for palmDSC to cut out the laptop. I have a laptop I could use but it's a bit clunky and brings issues of power and light pollution for fellow astronomers at dark sites so yeh.
Perhaps the box could be powered from the same source as a dew heater controllers... Or is the difference in voltage and amps too great.
Ek's box has its own power regulator... so anything between 8-15V is ok (if encoders are more power-hungry, there may be an issue with on board regulator (7805). The best idea is to mount in on heat sink.
I use car battery for power supply. Its second hand one that cant be used for car anymore cos it has only 150 CCA (Cold cranking Amps) but more than enough to run EK box for whole week . Its small narrow battery that easy fits next to handle of my Bintel Dob base. I put one screw on opposite side of handle and wrap peace of cable to secure the battery in place.
If you go to any mechanical shop and ask for second hand battery from Toyota Corolla or some other small one they will give it to you maybe even for free.
About serial port; I use serial to USB cable converter that I bought from Jaycar. There is model number here somewhere on this topic I left before. It works great!
The good thing about car battery I use home made dew heaters as well and next day check the voltage and its still 12V! I do have battery charger that can be bought for around $40 dollars.
I got Eee PC Asus netbook that runs CDC software on it. The battery lasts anywhere from 7-9 hours! I got it from Office Works for $379 dollars with Win HP.
Everything works great, thanks to Bojan and Simon for their help! And other guys here who are always willing to give you advice.
Hi,
is it possible to use the Bartels system with a seperate stepper driver, so only clock and direction signals would be required and the stepper driver would handle microstepping? I was thinking of taking signals from the port.
there would be optical encoders with ek's box, so the system would receive position information, just wanted to replace the driver part.
MotorControlMethod should be set to 1 (I think... )
Perhaps you should try this and observe with CRO what is happening at LPT port.
However, since I don't use this method (I have parallel driver), I think it is better for you if you go to Yahoo group and ask somebody or Mel himself, he is one very helpful guy and I am sure he will reply quickly
Well everything came in today, the encoders from US digital, the PCB and IC's from FAR and bits and peices from RS Components and Jaycar. Also got a pocketPC from a friend for a bottle of scotch. Good news is i can start soldering and MAY have it working for the local star party this saturday
...bad news is that the encoder (US digital S2) that i was taking with me to Jaycar to find suitable cables for is different to those that i actually ordered (US digital S6). So the cables i made up won't fit at all. The cable part of things is fast becoming the most troublesome. I'm open to any suggestions guys. May end up buying the cables from US digital anyhow.
I'll try get a parts list with the RS components and Jaycar part numbers up here for future box makers. 1st pic is the S2 encoder, pic 2 is the S6/
The cable part of things is fast becoming the most troublesome. I'm open to any suggestions guys. May end up buying the cables from US digital anyhow.
So, what exactly is the problem?
As I can see, your encoder has different connector... and that's about all (I am pretty sure RS components or Farnell will have adequate latching plugs/sockets. It seems to be similar to those used for audio connections inside computers, between CD and audio card. Perhaps non-latching one will also fit in).. unless you ended up with differential interface.. which again is no issue because you should use only positive outputs.
The problem is finding the right connectors. I Havent come across them yet on the rs components site and I'll give farnell a go.the salesman gave me a molex part number so searches might be a little more fruitful now. The shipping from us digital Is a flat rate of 55USD
OUCH.. That is a lot..
I am sure there exist a cheaper solution.
If you can't find connector, you still have an option of soldering wires.. yes, it may be un-acceptable proposition to some people.. but so is their price for the connector.
Has anyone had problems fitting the right angle headers into the pcb holes. Its very very tight for me...am i missing something? Are they not supposed to go straight through?
Also, on a female DC socket (to plug a power adaptor into for example) there are three metal tabs. Which is the positive and which is ground?
Last edited by Tiotion; 03-09-2010 at 09:35 PM.
Reason: Added another question
First attempt...fail. Found a cap was in the wrong orientation, fixed it, still nothing. Checked for bridges, none, checked oriention of other parts...good. Except the PIC and MAX232. What is their correct orientation? Mine are seated such that the text on these is the same as the text on the board.
Still having issues fitting the encoder headers to the board. I had them so the pins were flush with the board, couldn't get them to go straight through. This isnt good enough and will loosen over time. I may need to drill the holes but i only have a 1mm drill bit.
EDIT: Also, ive snapped one of the pins on the max232. Its on the second row, last on the right hand side. The pin has come off at the point where it thins in to fit into the socket. The way it is currently positioned, the pin does not connect to anything, but if this orientation is incorrect, then i may have issues. Do i need a new one? Good thing jaycar have them (CAT. NO. ZK8824)
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