The LED driver works!

I found the remaining inductor and soldered it onto the board. And I also added the connector, connected it to a LED and a power supply and switched on. And see! It works! Without any fiddling or whatever :)

And immediately I had to play around with it and combine it with a PIR sensor. The nice thing is that the circuits are almost fully compatible. The ouput of the HC-SR501 can be directly connected to the PWM input of the LED driver. And both run on the 12V power supply. Unfortunately the PIR will only work up to 20V so my planned 24V will be a bit too much for it.

Panelize: The Result

Today I got my PCBs:

They look very nice :) Except that the mounting hole has not been drilled, very clever ;) Have to find out what went wrong, but I guess I forgot to include the NPTH drill file. Who cares, maybe I’m going to cut away the last centimeter of the board anyway.

Here is one cut away and almost fully assembled:

I hope the PT survived the soldering torture. Hand soldering these is not so easy because they should have solder below them to make better thermal contact. I’ll find out if it works as soon as i found out where my inductors are hiding…

Adressable SPI

Sometimes I wish that SPI slaves have an address similar to I2C devices. Then I could connect all SPI devices to the same 4 lines: SCK, MOSI, MISO and SS. This would save all but one salve select lines. Pull SS low, send address, the addressed device listens and enables its MISO, the rest as usual. When finished talking to the selected device raise SS.

A long time ago I was talking to a friend about this idea, and if it is possible to put this into a GAL. The answer is yes.

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FTDI Vinculum II

I think I saw these chips before but today I took a closer look. It’s a very interesting 16bit CPU running at 48MHz (or 12/24 when saving power). This chip (maybe) has 2.5 times the power of an AVR. I like these small DIP boards. The official site contains a lot of information. Unfortunately I haven’t found (yet) any information about the instruction set.

A binutils and gcc port for this chip would be nice. I don’t want to use a strange IDE, especially not on WinDoS.

Panelize Kicad PCB

Edit: got a permanent place here.

Making PCBs is fun these days. Years ago I always paid a lot of money and got one single layer PCB without mask or silk screen. Now there are many PCB manufacturers which make prototyping PCBs for reasonable prices. But normally they don’t allow you to make panels (putting multiple circuits on one PCB). At least two manufacturers exist which allow you to create up to 5 panels per PCB: and (their PCB options look so similar that I think it’s the same manufacturer).

But how do you create the panelized production files?

Doing it by hand is too cumbersome. It could be done with the gerber files. But I chose to write a little python script which duplicates the specified parts in a kicad PCB file (.brd). The advantage is that the panelized version is still editable with kicad and I still can run the checks.

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Paypal sucks.

I wanted to order some electronics parts from a company China and since I am in India I obviously wanted them to be delivered to India. I thought “nice, they support Paypal” when I wanted to pay. But soon I found out it’s not so nice. When trying to pay with may Paypal account I got a message along the lines “you can’t pay with your account if delivery goes to india”. I thought “OK, I try it with my credit card”. But same result. I could accept that if they would give the reason for this restriction, but they do not. Since I am from Switzerland I have a Swiss credit card and a “Swiss” Paypal account. Then I tried to change my address in the Paypal account. But the country cannot be changed. So I contacted Paypal. But their answer was “just add another delivery address in ebay”. WTF? I don’t want to buy from ebay. OK, next try with an Indian credit card of a friend. But now Paypal’s response is that the credit card is not valid. It is valid since it is used all the time. I guess Paypal just does not support “3D Secure” for Indian cards.

Conclusion: Paypal sucks. Don’t use it.

But they are not the only ones having trouble with Indian credit cards with D Secure enabled, Alipay for example also does not work, but it works with my Swiss card :)