19725eed4a
also, i didn't make a note of it in the *.md file, but Waveform Generation Mode 15 for fast PWM wasn't working right (well.. wasn't working how i expected it to). i misinterpreted what the modes were doing, partially (haha, or all-ly?) because i didn't read the description of fast pwm thoroughly enough... in any case, all the information's in the datasheet, and it's actually not terribly long. i'm not sure how to correctly use Mode 15 yet, but i think i'll leave it alone for now, since Mode 5 works as expected, and i think what the datasheet says about *that* makes enough sense to me for me to be content for the moment.
62 lines
1.7 KiB
C
62 lines
1.7 KiB
C
/* ----------------------------------------------------------------------------
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* ergoDOX controller: MCP23018 specific code
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* ----------------------------------------------------------------------------
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* Copyright (c) 2012 Ben Blazak
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* Released under The MIT License (MIT) (see "license.md") at
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* <https://github.com/benblazak/ergodox-firmware>
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* ------------------------------------------------------------------------- */
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#define TWI_ADDRESS MCP23018_TWI_ADDRESS // from header file
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#define True ((uint8_t)1)
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#define False ((uint8_t)0)
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// register addresses (see "mcp23018.md")
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#define IODIRA 0x00 // i/o direction register
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#define IODIRB 0x01
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#define GPPUA 0x0C // GPIO pull-up resistor register
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#define GPPUB 0x0D
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#define GPIOA 0x12 // general purpose i/o port register
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#define GPIOB 0x13
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#define OLATA 0x14 // output latch register
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#define OLATB 0x15
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// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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#include "lib/arduino/twi.h"
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#include "mcp23018.h"
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void mcp23018_init(void) {
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uint8_t data[3];
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// set pin direction
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// - unused : input : 1
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// - rows : output : 0
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// - columns : input : 1
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data[0] = IODIRA; // start register address
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data[1] = 0b11000000; // IODIRA
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data[2] = 0b11111111; // IODIRB
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twi_writeTo(TWI_ADDRESS, data, 3, True);
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// set pull-up
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// - unused : on : 1
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// - rows : off : 0
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// - columns : on : 1
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data[0] = GPPUA; // start register address
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data[1] = 0b11000000; // GPPUA
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data[2] = 0b11111111; // GPPUB
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twi_writeTo(TWI_ADDRESS, data, 3, True);
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// set output pins high
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// - rows : high : 1
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// - other : low : 0 (or ignored)
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data[0] = OLATA; // start register address
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data[1] = 0b00111111; // OLATA
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twi_writeTo(TWI_ADDRESS, data, 2, True);
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}
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