MuIn USB - How to connect Switches on PortB

Gianni — Mon, 06 Dec 2010 19:50:33 GMT

If you're going to connect some switches on your MuIn USB (using your firmware), you can consider using PORTB since it has integrated pull-up resistors: one pin of the switch will be connected to GND and other pin on PORTB Input. You'll detect the button pressed with some instructions like those:

if (!LATBbits.LATBx) // x=0...7
{
// instructions to execute if button pressed
}
else
{
// instructions to execute if button not pressed
}

To activate integrated pullup resistors you must include portb.h library in top of your program:

#include

and the activate pullup resistors with dedicate function:

EnablePullups();

Notice tha inputs B0 and B1 are also used by I2C peripheral. If you want use them for switches, you must solder the I2C jumper-pads on the botton of MuIN USB however: solder pad 1 with pad 2 to connect an external pullup resistor on B0 and B1.

If you don't do this, pushing a button on B0 will cause also B1 toggling and vice-versa.

A very simple stand for MuIN LCD

Gianni — Mon, 22 Nov 2010 18:24:40 GMT

Is quite simple make a simple stand for your MuIN LCD! All you need is:

A sheet of PVC, at least 110x110 millimeters

Ruler

Cutter

A pencil

A drill

4 F/F hex spacers, 12mm height with screws

A Caliper (optional)

Using Caliper or Ruler, measure your display's dimensions and paint the shapes on PVC using the pencil. The external dimensions I've used for the stand are 110 x 100mm:

Cut the display window using the cutter and drill the 4 holes used to anchor display on the stand

Screw-in the hex spacers on the back side of LCD.

In the following pic you can see I've used 2 F/F 1.2mm Hex spacers on the upper side of LCD and 2 F/M 1.2mm Hex spacers on the back side. On the male side of 2 lower hex spacers I've screwed in 2 F/F 2.5mm hex spacers and then I've attached here a small piece of a protoboard:

The protoboard is then connected on 8 pin male header of muin LCD using a female header soldered on the back side:

Here you can see some other pics:

Finally you can attach LCD on the stand using 4 screws:

On the back side, in order to mantain the assembly in upper position, I've used two common "L" washers mounted on lower hex spacers:

Your simple MuIN LCD stand is ready to display all that you want, just in front of you !!

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MuIn USB - How to connect Switches on PortB

A very simple stand for MuIN LCD