Small Stuff

SMD Adapters
  • SOT23 to DIP adapter:

One day these will be handy when playing with tiny I2C DAC chips such as the MCP4716.

sot23

  • SOT89-5 to DIP adapter:

Made for prototyping with PT4115 LED drivers.

  • SOP24-300-1.00 adapter:

Made for prototyping with MBI5030 PWM LED drivers. I’ve added cut-able traces for all pins, so it gets a bit easier to wire them to Vcc or GND.

  • MSOP10/TSSOP8 to DIP adapter:

You really can’t prototype with small (and I mean small) SMD chips on perfboard anymore. That’s why there should be MSOP10/TSSOP8 to DIP adapters!

Breakout boards
  • MBI5168 SMD breakout board:

No need to carry around a large breadboard or trying to get these chips soldered on perfboard anymore. Now I can just use these tiny (32x32mm) boards if I need something that works ASAP. The MBI5168 can be pushed to sink up to 120mA per channel, but you need to keep a vigilant eye on the power dissipation! This board comes with 2 small decoupling capacitors (100nF + 10µF) for the logic part, 1 potentiometer (1k) for setting the current and a 180Ω resistor that limits the maximum current to 100mA. Boardsize: just 32 x 32mm ! The design files are here. It can be used much like a plain 74HC595 shift register, but provides constant current control using just one potentiometer. Up to 100mA per channel if the total thermal dissipation of the chip is not exceeded. Can be used with the arduino ‘shiftPWM‘ library.

  • MBI5168 DIP breakout board:

Same thing as the SMD breakout board, just with a DIP chip. Is it useful? Maybe… Boardsize: 32 x 43mm. Click to download the design files.

Small projects

  • LED-strip PWM controler with IR receiver:

Based on an ATtiny85 microcontroller to do the IR decoding. Signals are received by a TSOP38238 demodulating 38kHz IR receiver. Switching is done by a logic-level N-channel mosfet that can take several amps without needing a heat-sink. In this case it is the IRLR2905. Dimensions: 25×25 mm.

LED-strip_PWM_IR-2nd-rev

  • IR raw receiver:

A little board that receives 38kHz modulated IR radiation, which is typically used by remote controls, using the TSOP38238. The code on the ATtiny85 does the signal recognition and sends out byte-sized commands to whatever is connected using a bit-banged serial output.

Now with a voltage regulator and new header / silkscreen. No more 12V accidents ;-)

  • Tiny LED ring-light:

This little thing was created to assist my old digital camera during macro photography. Alternative applications: SMD inspection, microscopy… Relevant blog post

This and that
  • Openbench logic sniffer pull-up/down wing:

The OLS is a very nice and affordable device. There’s one issue though: floating inputs. They show up as random noise or cross-talk from other channels.This little add-on will enable you to add 10k pull-up or 10k pull-down resistors as you like using easy to use piano-style dip-switches. The pull-up voltage is selectable in two banks from 5.0V, 3.3V and 2.5V (‘borrowed’ from the OLS itself with a 4-pin connector). Boardsize: 50 x 50mm.Please don’t ask me about propagation delays, balanced trace lengths and so on. It’s just a simple board.

Currently I’m waiting for the boards to arrive from elecfreaks.

Edit: It works! Pull-up resistance at 2.5V needs to be about 4k, at higher voltages 10k seems to work fine. Pull-down works with 10k just fine (so far). I have 9 boards left over (bare PCB, no parts). If you want one click here.

A discussion on the subject in the dangerousprototypes forum.

And finally the fully assembled version is ready.

It works satisfactorily up to 100MHz sample rate + RLE. At 200MHz things still look OK, but when using RLE as well only grounding the probes gets rid of the unwanted crap creeping over from other channels. Using a lower than 10k pull-down resistor network might be a way too.

The discussion on the forum has taken off lately, lots of good information there. The next hardware version of the OLS may even come with shielded probe wires. Who knows. It would also be nice if unused channels could be suppressed in the software.

  • Openbench logic sniffer pull-down wing:

Bare-essentials ‘pull-down only’ variant of the OLS wing. Smaller PCB, less parts and therefore cheaper to make! If you’re only interested in ‘silencing’ unconnected probes and don’t care about pull-up resistors, this is the thing to use. Note: the ‘full’ version can do the same, if you only populate half of it. The design files are part of the full version.

  • Capacitive sensor(s):

A first test with this kind of sensor. Ordered at OSHPARK, the real thing will be purple.