Microcontrollers and stuff A blog by Derk Vedelaar


Self soldered adxl345

I received some adxl345 chips (2). They where even smaller than I imagined. 5.3mm by 3.3mm. 14 pads to solder. I'm never going to solder that thing. Ok ordered a pcb from ebay (pic) and some caps. See if I can make it work.

The chips came with the warning to preheat the chip for 24 hours at 125 degrees celcius. I did not do that. Warnings are there to be ignored.

So, I always solder small things like this one using solder paste. Turn on the oven (I have one that reaches 265 degrees celcius). Then apply the solder paste on the pads and put it in the oven. With the bigger smd parts that works fine. But this was too small and the solder paste was everywhere. I tried it anyway and it turned out that there was way too much solder on there. So I put it back in the oven and when the solder was wet quickly removed the chip. There was a whole blob of solder on the pcb and I removed it with a soldering iron and a solder sucker. Back in the oven for the second time, but this time with some solder already there on the chip and pcb. I added a little bit more paste where needed and a lot of flux.

When it came out of the oven it was hard to see if it was connected correctly, so I tried it.

And guess what? It works!

Here is a picture of it:

Yes you can see the flux (I did not clean it) but I don't really care. I direcly ordered a second pcb (I had 2 adxl345 chips and only one pcb) to try my luck again.

By the way, I tested the module using this arduino code.

Posted by Derk