A couple of people have asked how they can make BAR LED boards like the ones we used for the blinken-lights demo
We use them all the time - they're really useful when you need to monitor the state of a byte-wide input or output.
We recently simplified the design by using a resistor array, and the boards are now really easy to make on strip-board.
Here is the new version, seen from the front and the back:
Here's the stripboard diagram, courtesy of Fritzing. The bar led is transparent, so you can see the breaks in the tracks beneath it; you can also see a couple of breaks just to the left of the BAR LED, and there are breaks in each track under the ULN2803.
Thanks Romilly that’s very clear. One question for you… Do you have a good source for components? I normally source bits from Maplin but more an more often I’m finding that they don’t have what I need.
We buy most things from Farnell and RS Components. Maplins are sometimes useful for stock items you need in a hurry, but they have a very limited range, and they cost more.
I’ll add some links to the components we used later today.
Thanks – heading off to Farnell right now :-)