Jun. 26th, 2017

xiphmont: (Default)

Another catch-up post.

A few weeks ago, I accepted my first order for a T43 backlight kit. It turned out to be a c-c-c-c-c-combo-breaker!

In the early days of software-controlled brightness, ThinkPads used an analog brightness signal like just about every notebook. It was generated by one of the D-to-A pins on the embedded Renesas H8S microntroller all ThinkPads used.

As of the X40, ThinkPads went to using a digital PWM brightness control generated by the Intel Centrino ICH Southbridge. This made them kind of weird by laptop standards. It's one of the reasons I had to cons up custom LED drivers for my ThinkPad brightness kits.

In general, the T and X series of the same generation shared a basic architecture. The planars were quite different, but the chipset and basic design were the same. Not so with the T4X and X4X.

The X40-series is a completely different design from the T40-series. It uses a PWM brightness control. The T40, however, is analog like the older machines, which threw me for a loop at first. The good news is that I'd made working drivers for the X2x, X3x, T2x and T3x beforehand, so once I realized the T4x was an 'old' style, getting it to work wasn't hard. I can use the same positive-analog TLD2 hack that worked on the earlier models.

The bad news is all my fabrication, based on the TLD3, is geared toward the PWM-based ThinkPads. The TLD3 boards aren't able to use a positive-analog brightness signal no matter the hack. For a TLD3, it's PWM input or nothing.

I have on hand ~ 1500 TLD3 PCBs, waiting to be populated, for the usual PWM kits. I have only ~ 20 TLD2 PCBs left that can be pressed into analog use.

Get 'em while you can.

xiphmont: (Default)

Given the two laser control panels and the design comparison, what's the actual goal here?

The first goal is functional: I need to add a number of new control and status functions.

Second: I am a vain man, and I want this tool to look a little less hokey. Not entirely, just a little. I mean, I gotta be me.

The biggest addition will be a software control for the laser. I somewhat arbitrarily decided to go with a rebranded Anywells controller from LightObject-- I'll find out later if that was a good idea or not.

The huge, spread-out, not-calibrated-to-anything digital PWM laser current control gets replaced by a thumbwheel implementing a Kelvin ladder. And instead of a 7-segment LED display that simply goes from 0-100, I'll use a good-old analog meter that measures actual milliampres.

While we're at it, a matching analog meter reads cooling water temperature.

Like on the American control panel, the key switch is the only power on-off, and the emergency stop will be a real immediate-stop interlock.

I have an onboard air assist, so that needs a switch too, along with a lighting switch and two switched laser pointers, one a centering beam and another for focus.

And, why not steal the tube runtime meter from the nifty panel as well? :-)

Last of all, arrange it in a more 'American' style: functions grouped together, consistent labeling, and no angry color salad. And just one or two inside jokes, because the tool is still a bit hokey.

xiphmont: (Default)

[me, pulling into parking lot, looking around for an open house at a makerspace I've not been to]

Yeah, I think this might be the place.

(Thanks Mike for letting me sit in your DeLorean :-)

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