(Updated 7/15/2019 - See Below)
During my roadtest of the PicoScope 5444D MSO, one of the disappointments that I had was with the quality of the supplied Digital Probes. Here are my comments from the review:
- The quality of the probes felt a little cheap for this nice of a scope. The plastic felt very cheap and brittle, while the probes did not operate smoothly (very sticky and sometimes refusing to slide at all).
- The marking on the probe tip connectors were somewhat difficult to read, which along with the strange mapping made it quite difficult to attach the probes to the board under test. Placing the marking on multiple sides of the connector and/or using color-coded wiring (or connector shells) would have made this a lot clearer.
In an attempt to address these concerns, I starting looking around and I even posted a question to the community (Wire/Cable Markers ). After a while, I just decided to order the markers (https://www.element14.com/community/external-link.jspa?url=https%3A%2F%2Fwww.newark.com%2Fhellermanntyton%2Fw1-270%2Fcab… ) and give them a try. They were a little loose for the gauge of the wires on these probes, but a bit of heat shrink and here they are:
The marker clips are a little too wide to allow me to attach wires side-by-side to a 0.1" header, but at least I can more quickly identify the leads, by either the color coding of the markers or by the slightly larger font. Also, I found a bunch of grabbers from an old HP logic analyzer (that I still have not unpacked from my move of almost 3 years ago). The combination of markers and clips should help make these probes a little more usable.
After working with this modification, I noticed that the clip on markers moved a little to freely and the thickness of the markers made in difficult to have probes placed on adjacent pins of a header. This got me thinking if maybe there was a better solution. While shopping on element14 to claim my project14 winnings, I started looking for colored heatshrink (1/16 ") that I could use to mark my wires, but I was unable to find the 10 colors necessary (this might make a nice assortment/kit). I ended up just ordering some clear heatshrink with the thought of using it over colored tape/labels.
I designed some labels that contained the probe number along with a standard 'resistor' color coding stripes (as I could not print white, I used a dashed line (clear/black) for '9'). I went with stripes on either side of the probe numbers, with the outermost stipes being the '10s' field (either black or brown for probe numbers 0-15). These labels were then printed onto clear labels (return address style) with my color laser printer. Here is a sample of labels and finished probes.
The colors did not come out as nice as I would have liked (D8 - the gray is almost black and some color were not vivid enough or smeared), the labels did make it considerably easy to locate a specific probe as I added probes to a debug connector on a board I was testing. These will work for now, bit I still might come back to this design to see if I can improve on it.
Gene
Update - 7/15/2019 -
Not too long after posting this blog entry jw0752 (Thanks John!) had suggested using multi-color heatshrink tubing to mark the wire numbers. I immediately searched on Ebay and found the 10 colors (resistor color codes) available in 1/16". I had been a little busy, but ran into some time today and decided to try it out. Here are the results:
Using the standard resistor code colors, I used two pieces of heatstrink per wire. The first piece, represents the 10's place, I used black (0) or brown (1), using 0.3" of 1/16" heatshrink tubing. For the second piece, representing the 1's place, I used the remaining colors, using 0.1" of 1.16" heatshrink tubing which I centered over the first piece. For D0 (black/black) and D11 (brown/brown) I left off the second marker. (Note: the heatshrink supplier sort of cheated on the green and blue tubes as these were actually small diameter, fortunately I had also ordered some other sizes of these multi-color heatshrink (1/8" and 3/16" diameters) so I was able to substitute the 1/8" diameter for the second piece). The results are far more readable and I am quite happy with the readability of the leads.
In applying the heatshrink, I did run into a couple of problems, due to the distortion that I had cause on the black molex connector housings. In my last attempt to use labels and clear heatshrink, I reattached the housing prior to shrinking the plastic and I messed up a few of the plastic housing. The D2, D6 and D8 housing were so distorted that I had a very difficult time extracting the wires from the housing so that I could slip on the heatstrink pieces. I need to use some very solid tweezers to 'tweak' the housing openings enough to slip out the contacts. This time to prevent further damage to the housings I shrunk the tubing with the housings off.
In shrinking the tubing (before and presently) I used https://www.newark.com/nte-electronics/hg-300d/input-power-350w/dp/80R3536?st=heat%20gun that I received from Newark using one of my $100 carts from project14 prizes (Thanks element14!). I am super happy with the performance of this heat gun, once I stopped and read the directions to better understand the two heat ranges. This tool has found a well deserved spot on my workbench.
Thanks for reading!
Gene
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