deskthority

Soarer wrote:The first one looks neater... you could even put the DIPs inside the 11x8 matrix, on say C2,C3 and R3,R5,R6. Or maybe on all the blanks in C14.

Soarer wrote:Using a new column is just... inelegant The two ways I suggested give a choice between using only 5 connections to the DIP switches (2 columns + 3 rows), or 7 connections with 6 rows used on C14. If you're building it on stripboard the C14 way might be easiest, or clearest, even if it is more connections.

Port B is a good one for the inputs (rows) - it's the only complete 8 bit port that's clear. Also, if the firmware supports a low power sleep mode (perhaps not now but in future) then port B works well to wake up the Teensy. It really doesn't matter much which pins you use for the strobes or LEDs, unless the firmware is easier to adapt to certain arrangements.

Soarer wrote:Forgot to mention, in case you didn't realise, you could put the rows onto port B in any order if it helps with the layout.

alfa147x wrote:Gf's parents are visiting tomorrow.

webwit wrote:

alfa147x wrote:Gf's parents are visiting tomorrow.

Get your weirdest keyboards out.

• Apple Bluetooth wireless bluetooth keyboard
• Logitech K120
• Random $3 MicroCenters keyboard
• Das Keyboard Pro Model S
• MiniLa

Muirium wrote:Yes, I've always wondered why any USB keyboards don't have hubs. It's the perfect place to plug in a memory reader etc. at random, let alone a mouse.

I got one of these little solar powered hubs recently. (For use with iPad and camera connector kit.) A powered hub may be overkill, but keyboards aren't the worst place to put solar cells, either.

Muirium wrote:Got a link to the code you're looking at?

alfa147x wrote:

alfa147x wrote:How does this look?

Old layout

Older layout


See any problems?

Soarer wrote:Each port on the AVR consist of (up to) 8 pins and is controlled by three registers...

DDRx - Direction - each bit sets whether the corresponding pin is input (=0) or output (=1).
PORTx - For an output pin, the output state. For an input pin, setting a bit to 1 activates the pullup resistor for that pin.
PINx - Input. (Also can be used to toggle output states, but not relevant here).

So, the first line clears the direction bits for pins PB0..5, and the second activates the pullup for those pins.

/* Row pin configuration
 * row: 0   1   2   3   4   5
 * pin: B0  B1  B2  B3  B4  B5
 */
static void init_rows(void)
{
    // Input with pull-up(DDR:0, PORT:1)
    DDRB  &= ~0b00111111;
    PORTB |= 0b00111111;
}

static uint8_t read_rows(void)
{
    return (PINB&(1<<0) ? 0 : (1<<0)) |
           (PINB&(1<<1) ? 0 : (1<<1)) |
           (PINB&(1<<2) ? 0 : (1<<2)) |
           (PINB&(1<<3) ? 0 : (1<<3)) |
           (PINB&(1<<4) ? 0 : (1<<4)) |
           (PINB&(1<<5) ? 0 : (1<<5));
}

/* Column pin configuration
 * col: 0   1   2   3   4   5   6   7   8   9   10  11  12  13  14  15  16
 * pin: D5  C7  C6  D4  D0  E6  F0  F1  F4  F5  F6  F7  D7  D6  D1  D2  D3
 */
static void unselect_cols(void)
{
    // Hi-Z(DDR:0, PORT:0) to unselect
    DDRC  |= 0b11000000; // PC: 7 6
    PORTC |= 0b11000000;
    DDRD  |= 0b11111111; // PD: 7 6 5 4 3 2 1 0
    PORTD |= 0b11111111;
    DDRE  |= 0b01000000; // PE: 6
    PORTE |= 0b01000000;
    DDRF  |= 0b11110011; // PF: 7 6 5 4 1 0
    PORTF |= 0b11110011;
}

PORTF |= 0b00000010

PORTC |= 0b10000000

Soarer wrote:Hmm, how much do you know about C's bitwise operators? &, |, ~, << etc.

Looks like you got the relationship between logical bits and physical pins OK.