OSH Park
Profile for Heisenbug
Shared projects
L298 Motor Driver Breakout
by
Heisenbug.
2
layer board of
2.40x1.73
inches
(60.99x43.82
mm).
Shared on
April 3rd, 2015 00:42.
$20.70 / set of 3 - untested (will update)
Motor driver chip good to ~40V / 2A cont (3A pk) and power dissipation limited to 25W or by size of the (probably insufficient as designed) heatsink used.
Screw terminals and Hard Disk power connector used for convenience. Need either a jumper or Rsense across each G/S (ground/sense) terminal pair, and a 7805 ONLY if supplying power solely via +Vmotor. Pads for either PTH or SMD resistor/LED pairs on motor outputs are independent from other half of each H-bridge; BOTH will light if pulled high.
Flyback clamping diodes are DO-214AC package/pads, and should be rated for at least 2A, 40-50V.
DS1337 RTC+Supercap+7805 I2C module v3
by
Heisenbug.
2
layer board of
1.00x0.90
inches
(25.35x22.86
mm).
Shared on
March 29th, 2015 10:14.
$4.45 / set of 3
Physical assembly designed with the intent to be used in more of a vertical orientation, e.g. on a right-angle header plugged into a breadboard.
Batteryless clock module - now more shrinky than the old version!
Features access to all DS1337 IO pins plus a separate IO voltage supply for their pull-up resistors, and accessible connections to both sides of the discharge-blocking diode between the supercap and regulator.
DS1337S on top, Supercap (I chose a 1.5F that happens to have 30+ohm ESR) and 78L05 (SOIC version 5-volt regulator) on bottom, and one or a pair of [low-Vf] diodes makes for a batteryless clock module that will happily keep time with somewhere around monthly charging, on anything from 7+v (using regulator) or can be run direct on 1.8-5v.
Other passives on board bottom include 2 ceramic SMD caps (0.1u suggested) and 3 of the 4 SMD 0805 10k resistors, and on board top, 2 small electrolytic/tantalum, the last SMD 0805 10k resistor and the optional alternate PTH 10k resistor.
Charge session[s] should total 24-48 hours per month for better results with high-ESR supercaps.
The regulator can also power other small circuitry; just keep in mind power dissipation and current rating (~1W or 100mA).
ATtiny24/84 IR Arcade prototypical mess
by
Heisenbug.
2
layer board of
2.00x1.70
inches
(50.80x43.18
mm).
Shared on
March 20th, 2015 21:50.
$17 for 3 break-apart boards, each containing gun (narrow strip) and target (larger).
IR arcade shooter gun + target w/prototyping space, needed since the designs come with 2 totally different flavors of target…Grrr.
The Makezine project’s article online says one thing, but the project designs on the author’s site show something entirely different. Since I planned to make the boards with flexibility built-in already (for other unrelated future prototyping & experimentation), I decided to also make it easy to cut traces around the IC socket on the back of the target board and arbitrarily rewire things if needed (probably so.) The rear silkscreen makes it more apparent if cuts have been made, as well as highlighting the cut lines.
Muttering to self about the stupidity of having coexisting proprietary and open designs…
Clearly, both schematic design and board layout are untested, but they should at least work for experimentation/prototyping.
RTC+SuperCap+7805 I2C module
by
Heisenbug.
2
layer board of
1.04x1.04
inches
(26.34x26.42
mm).
Shared on
March 20th, 2015 21:41.
$5.35 / set of 3; but you can now get the new smaller version here for $4.50
Designed more for vertical use, e.g. right-angle 9pin header plugged into a breadboard.
DS1337s on top, Supercap (I chose 1.5F) and 78L05 (SOIC version 5-volt regulator) on bottom, and one or a pair of [low-Vf] diodes makes for a batteryless clock module that will happily keep time with monthly charging, on anything from 7~18v [using regulator] or can be run direct on 1.8-5v.
Don’t forget to install the jumper-wire, and charge session[s] should total 24-48 hours per month for better results with high-ESR supercaps.
The regulator can also power other small circuitry; just keep in mind power dissipation and current rating (~1W or 100mA).
Uploaded [originally] 10/20/2014 21:42.
9-Led Flashlight "Cheapies" R-board add-on
by
Heisenbug.
2
layer board of
1.70x0.80
inches
(43.18x20.32
mm).
Shared on
March 13th, 2015 22:40.
$6.80 gives you R-boards enough for 6 flashlights, so why not share them?
If this design is too small, try my newer version.
A high-tech twist for the cheap 9LED flashlights - cut off one of these round boards and surface-mount 2 15ohm resistors in the slots, remove the stock 3xAAA holder from the flashlight (use it elsewhere, like for an arduino or something) and use a Lithium-Ion 18500 cell instead! Then add this populated R-board between the back end (-) of the battery/cell and the switch/tailcap spring.
The only other part to add is some craft foam to wrap around the cell for cushioning, approximately 1/16 - 3/32 inch thick. Done!
The resistance added on this board prevents the Li-Ion cell from frying the LEDs with too much current, and 15ohm/2 (=7.5) conveniently approximates 20mA for each of the LEDs (total ~175mA max at full charge) so they’ll last nearly forever without burning out…but given the cheap construction of these flashlights, you may still need to remove the LED board somewhere down the road to mend/improve the edge-mount solder connections if it starts to flicker.
Be sure to get Li-Ions with protection boards built in, as you probably don’t want a fire in your pocket should anything happen to go wrong. I got protected cells and have had no trouble at all.
Assembly: 1 x 15ohm 1/4W resistor in each slot with leads bent to opposite sides of the board, ignoring the thru-holes for them. Solder down to exposed traces, building a center spiral on one side (to contact the back (-) of the cell), and keeping the center clear on the other side for the tailcap spring. Tin the center of the pad where the spring rests, though.
Bugs:
* The break-apart didn’t work - the cut-outs did not come through for me and it’s one solid board.
* Aside from the cut-outs not working out (and I discovered an explanation why), nothing to go wrong, except in assembly.
* I’ll update with images.
* Solder mask not laid out for the “center spiral” idea (front/back sides not differentiated), some scraping may be needed. YMMV.
* This design, at ~0.75", was too small to seat solidly in my flashlight and while it works, it also will slide around when the tailcap is removed. The fixed version for this cutout-fail is also increased to about 0.9" diameter to make a much tighter fit, but will need edge smoothing and rounding once broken apart.