2018.05.30

To make v2.0 useful:

Replace the 27k in the lower leg of the AP3012 comparator circuit with a 56k
to drop the voltage from ~27V to just under 12V.

In the AP3012 circuit, rotate the inductor and 4.7uF caps 90 degrees, and lift
pin 5 of the IC, to detach all of them from the 3.3V rail.  Use a wire to 
connect all of them to pin 4, the gpio driving the circuit.

The net effect is that we're making 12V from the gpio, which means all the LED
current and switcher inefficiency is coming as current through that gpio.  The
measured LED current is around 7mA, so this is "safe" for the SOC, but leaves
less engineering margin than we usually like.

Changing the circuit to be powered from v_lipo with the gpio hooked to shdn*
and controlling a FET switch on the output might be smarter someday?

2019.12.09
- what gets through-hole soldered on to a v2.1 board (sans optics)

	6-pin micromatch with locking ears
	2 * 9-pin screw terminal strips
	5x1 100mil straight header
	beeper
	LiPo connector
	edge-launched SMA
	2x1 100mil right-angle header

2023.02.10
- the LCD digits we've used, Lumex LCD-S101D14TR, are only available now if
  we're willing to order 3150 pieces at !.85 each or $5,827.50.  That's just
  not reasonable when we only need 3 per unit and a big build might be 35
  units!

- DK and Mouser both have the Varitronix VI-611-DP-FH-W in stock.  This is a
  6-digit LCD display whose digits are 25.4 mm tall instead of 34.54.  This
  LCD module would require the PCB width to grow an inch in width to 5.5 
  inches.  A quick look at the FreeCAD file suggest this is manageable without
  a complete re-design of the panel.  By using the panel to only expose 3 of
  the digits, we could mimic the existing functionality.  At $16.27 for q5 
  and above from Mouser, this seems like a credible way of making more TeleLCO
  in 2023?

2023.02.15
- we should have 31 SOC left after TeleMega v6.0 build if all goes well, which
  means we should target a batch size of 30 boards.

- 1170NF in orange is hard to get.  The part number is 1170-001-150. 
  mteagleent.com seem willing to sell me 30 pieces for $1,520.40 plus $15.00 
  shipping.  Pounce on it?

2024.02.17
- Keith thinks we should move (back?) to USB mini B for TeleLCO, and suggests
  we deliver:
	https://www.mouser.com/ProductDetail/172-PX0446
	https://www.mouser.com/ProductDetail/172-PX0441-2M00
	https://www.mouser.com/ProductDetail/157-PX0484

- Pelican 1170 orange is no longer available without foam.  Amazon has a good
  price for modest quantities once you include shipping.  Set up tax-exemption
  with Amazon in anticipation of using them for stuff like this, and ordered
  one unit to package my proto board.

- Avnet has the 12-click-per-rotation shaft encoders for a price at q30 that
  DK and Mouser only offer on q100 of the 16-click-per-rotation units, but
  they aren't stocked and have 16-18 week delivery times.  Since it's "only" 
  about $100 total difference on 25 pieces, do we really care?