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These LED patterns that you’ve just described do not make sense to me. I think either you have mis-identified the LEDs or something is severely wrong.
Blue LED D45 is the one connected from LED4 to LED5. To turn that on, we take LED4 high and and LED5 low.
Red LED D510 is connected from LED5 to LED 10, and red LED D104 is connected from LED10 to LED4. In order to turn on D510 or D104, we would expect to require that LED5 is high and LED4 is low — the opposite of what we’re seeing.
Can you please double check the numbers that you have cited, and — since it sounds like you might have removed a ring — also double check that each board is in the correct orientation– with the “*”s lined up one above each other, and solder joints on all three boards facing up.
Do all of the red LEDs work correctly, if you go around the circle? Any stray blue/green lights come on when you do so?
No, that on its own doesn’t have any clear possible cause. Look around further and see if anything else is related.
It is usually much harder to deal with “slight” or intermittent issues, as it may have to do with the performance characteristics of a particular LED, rather than a full missing solder joint or the like.
Great; that sounds like excellent progress.
I’m not sure exactly what you’re asking. An EggBot is generally not a good choice for painting on flat surfaces like an “unfolded” cone.
Looks great!
The nominal maximum weight of the pen is normally stated as 45 g. However, heavier weights (or especially rubber bands) can dramatically reduce the lifetime of the pen lift motor.
Liquid ink roller balls like the Pilot Precise V5 *should not* require any additional weight or force in order to work well.
First, I would urge you to be more careful with “resoldering” type work, as it is often possible to cause problems by resoldering or overheating things that don’t need to be soldered.
The 9 LEDs that are affected are (reading out the names from the green green board) D39, D93, D49, D94, D19, D91, D29, and D92. You can see how these are wired up if you refer to the schematic.
The two other LEDs connected to these are D59 and D95, located above D46 and D56, respectively. You may also see an issue present on those two, if you look carefully.
These 10 LEDs are the only 10 connected to the “LED9” signal. The first thing that you should check is the soldering on the “LED9” vertical jumper, and at resistor R9. You might check with your multimeter that there is 24 ohms of resistance between R9 (measured on the green board, or at any of the affected green LEDs) and pin 5 of the microcontroller. (Pin 5 is close to the rectangular outline at J2.)
Carefully inspect the soldering at all 10 of the affected LEDs. If you have the ability to, test the LEDs individually as well. A failure of any of these LEDs — due to overheating during soldering or bending stress — could result in what you’re seeing.
Octolively requires 5 V dc power, with at least 200 mA capacity per panel. I wouldn’t recommend running more thab
If you have a USB power bank that supplies 5 V output, and has at least 200 mA capacity per panel that you want to run, then yes you can do that.
You can purchase a USB power breakout cable, or make your own:
https://blog.adafruit.com/2017/12/05/turn-an-unused-usb-cable-into-a-5v-power-cable/ (Keep in mind that the colors of wire inside a USB cable may not be consistently labeled– you need to *test* the polarity before using a cable like this.)You should also be aware that standard USB cables are *not designed for high power applications*. See this discussion for example: https://electronics.stackexchange.com/questions/170292
Given the tiny wires in a standard USB cable, it really should be limited to 500 mA (two Octolively panels). If you have a special cable rated for 2 A of power, then you can power up to 10 Octolively panels. However, you should also make sure to check what the maximum current draw allowed on your USB power bank is. Not all are rated for that much current.A 5 V level shifter needn’t draw substantial current– should be fine.
Obviously, an all-software solution is quite clean as well.
A few people have done similar things. Technical pens are easy.
Syringe dispensers controlled by air pressure are a common way to go as well. Beware that there is a response time for air pressure to turn on or off, particularly with viscous or thixotropic substances. (You can add air pressure to the channel, but it takes time for the substance to move.)
One good precedent for glass capillary tubes is that some technical pens use sapphire tips. Beware that glass does wear down; paper is abrasive.
There is a “secret” provision in the software for controlling a digital output pin that is high whenever the pen is commanded down. Open up axidraw.py (in the Inkscape or CLI or python API) and look for
B3in the code. It appears on three lines. Uncomment those lines, and then digital I/O pin B3 will be configured this way. B3 is set up as a “servo connector” with ground, +5 V (very little current capacity), and the I/O pin. That’s the highest set of 3 pins above the regular servo connector.You can disable the servo moving by unplugging its cable or setting the pen-up and pen-down positions to be the same.
These are custom manufactured components. You won’t find them in a store.
It’s a cable guide. If yours has broken, please contact technical support about a replacement.
Yikes. That is not a very good lifetime. In most cases, with regular plotting duty cycles, servos last from months to years. However, some individual units do fail sooner. The most important considerations, as I already mentioned, are the conditions. Heavy duty cycle (constant up/down motion) can lead to heating, and that can lead to overheating under certain other conditions.
(I don’t have a date on it yet, but we *are* looking into servo alternatives for the future– hopefully we can end this once and for all.)
The AxiDraw should be connected to your computer through USB, which provides the grounding. If your computer is plugged in with an ungrounded two-pin prong, that is a potential concern. I have not heard of any specific issues with the belt building up a charge.
Lenore will follow up with you separately about the servo replacements.
My FTDI cable enumerates (on a Mac) as: /dev/cu.usbserial-FTE55RTK
I’ve updated the software in the repository and environment configuration instructions: https://wiki.evilmadscientist.com/Alpha_Clock_Firmware_v2
Please give it a try, and let me know how it goes.
