Andy K
This module provides a simple API to the Maxim MAX7456 on-screen display chip
Diff: MAX7456.cpp
- Revision:
- 0:d7cd54ad4c3d
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/MAX7456.cpp Tue Nov 16 10:47:25 2010 +0000
@@ -0,0 +1,303 @@
+/*
+ Copyright (c) 2010 Andy Kirkham
+
+ Permission is hereby granted, free of charge, to any person obtaining a copy
+ of this software and associated documentation files (the "Software"), to deal
+ in the Software without restriction, including without limitation the rights
+ to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ copies of the Software, and to permit persons to whom the Software is
+ furnished to do so, subject to the following conditions:
+
+ The above copyright notice and this permission notice shall be included in
+ all copies or substantial portions of the Software.
+
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ THE SOFTWARE.
+*/
+
+#include "mbed.h"
+#include "MAX7456.h"
+
+#ifdef MAX7456_DEBUG
+#include "IOMACROS.h"
+extern Serial pc;
+#endif
+
+#define CS_ASSERT _cs->write(0)
+#define CS_DEASSERT _cs->write(1)
+
+// This header should only be included once here in this
+// file as it compiles inline directly. Include within
+// the library namespace.
+#include "MAX7456CHARS.h"
+
+/* Map ASCII table to the MAX7456 character map.
+ Note, the MAX7456 in-built character map is no where near the ascii
+ table mapping and very few characters are available to map. Where
+ possible we create new characters for those we need that are missing
+ from the MAX7456 that we want to use and also we create some special
+ characters of our own that are not ASCII chars (crosshair for example).
+ These additional character definitions are listed below the table.
+ Character maps we have create can be found in MAX7456CHARS.h */
+const unsigned char MAX7456_ascii[256] = {
+
+ /* Regular ASCII table. */
+ /* 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F */
+ /* 00 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ /* 10 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ /* 20 */ 0x00, 0x00, 0x48, 0x00, 0x00, 0x00, 0x00, 0x46, 0x3F, 0x40, 0x00, 0x4d, 0x45, 0x49, 0x41, 0x47,
+ /* 30 */ 0x0A, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x44, 0x43, 0x4A, 0x00, 0x4B, 0x42,
+ /* 40 */ 0x4C, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19,
+ /* 50 */ 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x00, 0x00, 0x00, 0x00, 0x00,
+ /* 60 */ 0x46, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33,
+ /* 70 */ 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x00, 0x00, 0x00, 0x00, 0x00,
+
+ /* Extended ASCII table. */
+ /* 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F */
+ /* 80 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ /* 90 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ /* A0 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ /* B0 */ 0xB0, 0x00, 0x00, 0xB3, 0xB4, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xBF,
+ /* C0 */ 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ /* D0 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xD9, 0xDA, 0x00, 0x00, 0x00, 0x00, 0x00,
+ /* E0 */ 0xe0, 0xe1, 0xe2, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ /* F0 */ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+};
+
+MAX7456::MAX7456(PinName mosi, PinName miso, PinName sclk, const char *name, PinName cs, PinName rst, PinName vsync)
+{
+ init(mosi, miso, sclk, name, cs, rst, vsync);
+}
+
+MAX7456::MAX7456(PinName mosi, PinName miso, PinName sclk, PinName cs, PinName rst, PinName vsync)
+{
+ init(mosi, miso, sclk, NULL, cs, rst, vsync);
+}
+
+MAX7456::~MAX7456()
+{
+ delete(_ssp);
+ delete(_cs);
+ delete(_rst);
+ delete(_vsync);
+}
+
+void
+MAX7456::init(PinName mosi, PinName miso, PinName sclk, const char *name, PinName cs, PinName rst, PinName vsync)
+{
+ _ssp = new SPI(mosi, miso, sclk, name);
+ _cs = new DigitalOut(cs);
+ _rst = new DigitalOut(rst);
+ if (vsync != NC) {
+ _vsync = new InterruptIn(vsync);
+ _vsync->fall(this, &MAX7456::vsync_isr);
+ }
+
+ // Set default output signals.
+ CS_DEASSERT;
+ _rst->write(1);
+
+ // Setup the SSP.
+ _ssp->format(8,0);
+ _ssp->frequency(25000000);
+
+ // Reset the MAX7456
+ reset();
+
+ /* Write the custom CM map. */
+ write(0, read(0) & 0xF7);
+ for (int index = 0; custom_chars[index].ascii != 0; index++) {
+ write_char_map(custom_chars[index].ascii, custom_chars[index].map);
+ }
+
+ wait_us(100000);
+
+ /* Change the vertical offset. */
+ vos(0x16);
+
+ /* Set the blink rate. */
+ //vm1((3 << 2) | 3);
+
+ /* Enable display of OSD image. */
+ vm0(0x48);
+}
+
+void
+MAX7456::write(unsigned char address, unsigned char byte)
+{
+ CS_ASSERT;
+
+ /* MAX7456 addresses are always less than 0x80 so if the
+ address is > 0x7F then the caller is requesting an direct
+ 8bit data transfer. */
+ if (address < 0x80) { _ssp->write(address); }
+
+ _ssp->write(byte);
+ CS_DEASSERT;
+}
+
+int
+MAX7456::read(unsigned char address)
+{
+ int data;
+ address |= 0x80;
+ CS_ASSERT;
+ _ssp->write(address);
+ data = _ssp->write(0xFF);
+ CS_DEASSERT;
+ return data;
+}
+
+void
+MAX7456::reset(void)
+{
+ _rst->write(0);
+ wait_us(100000);
+ _rst->write(1);
+ wait_us(100000);
+}
+
+void
+MAX7456::clear_display(void)
+{
+ dmm(1 << 2);
+ while(dmm() & (1 << 2));
+}
+
+void
+MAX7456::cursor(int x, int y)
+{
+ uint16_t pos = (y * 30) + x;
+ dmah((pos >> 8) & 0x1);
+ dmal(pos & 0xFF);
+}
+
+void
+MAX7456::convert_string(char *s)
+{
+ while(*(s)) {
+ *(s) = MAX7456_ascii[*(s)];
+ s++;
+ }
+}
+
+int
+MAX7456::string(char *s)
+{
+ int len = 0;
+ dmm(1 | (1 << 6)); /* Enable 8bit write */
+ while(*(s)) {
+ write(0x80, MAX7456_ascii[*s++]);
+ len++;
+ }
+ write(0x80, 0xFF);
+ return len;
+}
+
+void
+MAX7456::attributes_xyl(int x, int y, char *s, int len)
+{
+ uint16_t pos = (y * 30) + x;
+ dmah(((pos >> 8) & 0x1) | (1 << 1));
+ dmdi(pos & 0xFF);
+ dmm(1 | (1 << 6)); /* Enable 8bit write */
+ while (len--) {
+ write(0x80, *s++);
+ }
+ write(0x80, 0xFF);
+}
+
+int
+MAX7456::stringxy(int x, int y, char *s)
+{
+ cursor(x, y);
+ return string(s);
+}
+
+int
+MAX7456::stringxy(int x, int y, char *s, uint8_t a)
+{
+ char *q = NULL;
+ int len;
+ cursor(x, y);
+ len = string(s);
+ q = (char *)malloc(len);
+ if (!q) {
+ return -1;
+ }
+ memset(q, a, len);
+ attributes_xyl(x, y, q, len);
+ free(q);
+ return len;
+}
+
+int
+MAX7456::stringxy(int x, int y, char *s, char *a)
+{
+ int len;
+ cursor(x, y);
+ len = string(s);
+ attributes_xyl(x, y, a, 30);
+ return len;
+}
+
+void
+MAX7456::stringl(int x, int y, char *s, int len)
+{
+ cursor(x, y);
+ dmm(1); /* Enable 8bit write */
+ while(len--) {
+ if (*s == '\0') break;
+ write(0x80, MAX7456_ascii[*s++]);
+ }
+ write(0x80, 0xFF);
+}
+
+void
+MAX7456::read_char_map(unsigned char address, unsigned char *data54)
+{
+ cmah((uint8_t)address);
+ cmm(0x50);
+ for (uint8_t index = 0; index < 54; index++) {
+ cmal(index);
+ wait_us(1000);
+ *(data54 + index) = read(0xC0);
+ }
+}
+
+void
+MAX7456::write_char_map(unsigned char address, const unsigned char *data54)
+{
+ unsigned char index, c, match = 1;
+
+ write(CMAH, address);
+ write(CMM, 0x50);
+ wait_us(20000);
+ for (index = 0; index < 54; index++) {
+ write(CMAL, index);
+ c = read(0xC0);
+ if (c != data54[index]) {
+ match = 0;
+ break;
+ }
+ }
+
+ if (!match) {
+ write(CMAH, address);
+ for (index = 0; index < 0x36; index++) {
+ write(CMAL, index);
+ write(CMDI, data54[index]);
+ }
+ write(CMM, 0xA0);
+ wait_us(20000);
+ while ((read(0xA0) & 0x20) != 0x00);
+ }
+}
+
+
+