Author Archives: admin

Device tree, setting GPIO2_1 as an input

With a BeagleBone Black with the latest image (6th June), I tried this device tree fragment: (Zip file contains the .dts and the .dtbo) test_fragment /* * pru dts file cape-bone-mytest-00A0.dts */ /dts-v1/; /plugin/; / { compatible = “ti,beaglebone”, “ti,beaglebone-black”; … Continue reading

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1mm and 1.25mm pitch connectors

Some photos to help identify connectors. These ones are JST SH which are 1mm pitch wire-to-board shown here, with surface mount connectors: These ones are Molex PicoBlade, which are 1.25mm pitch with wire-to-board (through-hole) and wire-to-wire examples shown here:

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Ultra portable pocket PSU

Although a bench PSU is useful, sometimes I prefer testing with something more portable. This ultra portable PSU has a footprint smaller than a credit card. It is perfect for travel. (Pen shown in image below for scale). I can … Continue reading

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7 segment Alphabet

A surprisingly large amount of the ASCII table can be represented with a 7-segment display. The image here shows what can be created. Here is the source code of the table used to create this. #define SEGA 0x01 #define SEGB … Continue reading

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Crimp pins, sockets and housings

Like it or not, the 0.1 inch spaced (2.54mm) header pins or sockets on PCBs are extremely common. There are also 2mm spaced alternatives, but they are still uncommon. Making up 0.1 inch connectors is a minefield; it can be … Continue reading

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fpga4fun – any good?

I personally feel a beginner is better advised to purchase a more open platform like Papilio One. The fpga4fun boards are closed, and some of the boards only have a block diagram; some of their examples are not supplied with … Continue reading

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Adobe Reader Internet access causes hangs

On my fast, SSD-enabled machine, every bit of software runs quick except for Adobe Reader. It got to the point that I was just going to uninstall it and replace with another free reader. Adobe ReaderĀ  XI (11.0.0) and some … Continue reading

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SAM-ICE connector pinout

The pin labeling is in the user guide, but the connector numbering was ambiguous. This photo and table snippet from the user guide shows the pinout. Click to enlarge.

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Component Storage

SMD devices like resistors and capacitors can be stored in tiny plastic boxes such as shown here. Make sure the label is written in fade-proof ink and that the labels won’t fall off within a year. I used tiny EPROM … Continue reading

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SMD soldering

This is a quick tutorial on how to solder an SMD board with 0603 and QFP sized components. This was the finished board: ‘0603’-sized components are fairly tiny; 1.6mm x 0.8mm. The image here shows some 0603 capacitors and the … Continue reading

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