Mes trouvailles du jour : 6 April 2015

microSD card reflow: quick and dirty PCB with Kicad

Ever wanted to add a lot a flash memory to a small microcontroller? NOR flash or EEPROM are ok, but only for small size. For Gbit range, you need NAND, and with NAND comes CCR, LUT, wearleveling, etc… Furthermore, they are darn expensive in small volume.

SD and microSD card are very interesting: they cost nothing, and you just need a SPI interface as the controller is included.

Last night, I thought: “why not reflow a complete microSD card”, as the card is composed of the same resin as chip casing and pins are flat bellow the microSD card and even golden, fore sure it should not be a problem to bring this to 270°C for 3 min….

Let’s try!

Here is the pinout

Then let’s create a small board, to try the reflow of a micro SD card and give access with some 2.54mm header.

Lets open Kicad and start with the schematic with Eeschema:

Then PCB new for the board layout:

Let’s submit the gerber files to OSH Park

Total including USPS post mail: 4.10€

That was my fastest board made ever, 1h30 from searching the pinout to the final  payment!

See you back in few week for the oven reflow test!

 

Mes trouvailles du jour : 11 March 2015

Simple CNC desktop router workflow and example

If you have access to a simple desktop mill/router, and you are not into mechanical part design, here is a very simple workflow:

Workflow

Sofware

You will only need free/open source program:

Example

In order to illustrate this example, we are going to make a case for a nice Nixie Clock from PV Electronics

A simple Ikea-hack will do for the wooden box: DRAGAN 2-piece bathroom dish set, bamboo

The front panel is milled

And fitted in place

The 2 stainless steel feet are from Ikea again

Thanks Dan Heeks for the very good software.

Happy milling!

Mes trouvailles du jour : 12 February 2015