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The Puma
Joined: 23 Apr 2004
Posts: 227
Location: The Netherlands
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| Problem with driving a MAX6952 |
 Posted: Sun Mar 05, 2006 6:00 am |
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I have connected one 5x7 led matrix display as descripted here (DIGIT0)
http://pdfserv.maxim-ic.com/en/ds/MAX6952.pdf
and i use my driver
| Code: | #ifndef MAX6952_CS
#define MAX6952_CS PIN_C0
#define MAX6952_CLK PIN_C3
#define MAX6952_DOUT PIN_C4
#define MAX6952_DIN PIN_C5
#endif
// Register address map
#define NO_OP 0x00 // Used when cascading max6952s
#define INTENSITY10 0x01 // Intensity register
#define INTENSITY32 0x02 // Intensity register
#define SCAN_LIMIT 0x03 // Scan-limit register
#define CONFIGURATION 0x04 // Configuration register
#define USER_DEFINED_FONTS 0x05 //
#define FACTORY_RESERVED 0x06 // Factory reserved
#define DISPLAY_TEST 0x07 // Display-test register
#define DIGIT_0_PLANE_P0 0x20 //
#define DIGIT_1_PLANE_P0 0x21 //
#define DIGIT_2_PLANE_P0 0x22 //
#define DIGIT_3_PLANE_P0 0x23 //
#define DIGIT_0_PLANE_P1 0x40 //
#define DIGIT_1_PLANE_P1 0x41 //
#define DIGIT_2_PLANE_P1 0x42 //
#define DIGIT_3_PLANE_P1 0x43 //
#define WRITE_DIGIT_0_PLANE_P0_P1 0x60 //
#define WRITE_DIGIT_1_PLANE_P0_P1 0x61 //
#define WRITE_DIGIT_2_PLANE_P0_P1 0x62 //
#define WRITE_DIGIT_3_PLANE_P0_P1 0x63 //
// Configuration register
#define SHUTDOWN_MODE 0x00 // Shutdown Control (data bit D0)
#define NORMAL_MODE 0x01
#define SLOW_BLINK 0x00 // Blink rate selection (data bit D2)
#define FAST_BLINK 0x01
#define BLINK_FUNCTION_DISABLED 0x00 // Global blink enable/disable (data bit D3)
#define BLINK_FUNCTION_ENABLED 0x01
#define BLINK_TIMING_COUNTERS_UNAFFECTED 0x00 // Global blink timing synchronization (data bit D4)
#define BLINK_TIMING_COUNTERS_RESET 0x01
#define DIGIT_DATA_PLANES_P0_P1_UNAFFECTED 0x00 // Global clear digit data (data bit D5)
#define DIGIT_DATA_PLANES_P0_P1_CLEARED 0x01
#define P1_BLINK_PHASE 0x00 // Blink phase readback (data bit D7)
#define P0_BLINK_PHASE 0x01
// Scan-limit register
#define DISPLAY_DIGITS_01 0x00 // Display digits 0 & 1
#define DISPLAY_DIGITS_0123 0x01 // Display digits 0 1 2 3
// Intensity register digit 0 and digit 2
#define DIG_0_DIG_2_DUTY_CYCLE_1 0x00 // Intensity min
#define DIG_0_DIG_2_DUTY_CYCLE_2 0x01
#define DIG_0_DIG_2_DUTY_CYCLE_3 0x02
#define DIG_0_DIG_2_DUTY_CYCLE_4 0x03
#define DIG_0_DIG_2_DUTY_CYCLE_5 0x04
#define DIG_0_DIG_2_DUTY_CYCLE_6 0x05
#define DIG_0_DIG_2_DUTY_CYCLE_7 0x06
#define DIG_0_DIG_2_DUTY_CYCLE_8 0x07
#define DIG_0_DIG_2_DUTY_CYCLE_9 0x08
#define DIG_0_DIG_2_DUTY_CYCLE_10 0x09
#define DIG_0_DIG_2_DUTY_CYCLE_11 0x0A
#define DIG_0_DIG_2_DUTY_CYCLE_12 0x0B
#define DIG_0_DIG_2_DUTY_CYCLE_13 0x0C
#define DIG_0_DIG_2_DUTY_CYCLE_14 0x0D
#define DIG_0_DIG_2_DUTY_CYCLE_15 0x0E
#define DIG_0_DIG_2_DUTY_CYCLE_16 0x0F // Intensity full
// Intensity register digit 1 and digit 3
#define DIG_1_DIG_3_DUTY_CYCLE_1 0x00 // Intensity min
#define DIG_1_DIG_3_DUTY_CYCLE_2 0x01
#define DIG_1_DIG_3_DUTY_CYCLE_3 0x02
#define DIG_1_DIG_3_DUTY_CYCLE_4 0x03
#define DIG_1_DIG_3_DUTY_CYCLE_5 0x04
#define DIG_1_DIG_3_DUTY_CYCLE_6 0x05
#define DIG_1_DIG_3_DUTY_CYCLE_7 0x06
#define DIG_1_DIG_3_DUTY_CYCLE_8 0x07
#define DIG_1_DIG_3_DUTY_CYCLE_9 0x08
#define DIG_1_DIG_3_DUTY_CYCLE_10 0x09
#define DIG_1_DIG_3_DUTY_CYCLE_11 0x0A
#define DIG_1_DIG_3_DUTY_CYCLE_12 0x0B
#define DIG_1_DIG_3_DUTY_CYCLE_13 0x0C
#define DIG_1_DIG_3_DUTY_CYCLE_14 0x0D
#define DIG_1_DIG_3_DUTY_CYCLE_15 0x0E
#define DIG_1_DIG_3_DUTY_CYCLE_16 0x0F // Intensity full
// Display-test register
#define NORMAL_OPERATION 0x00 // Normal operation
#define DISPLAY_TEST_MODE 0x01 // Display-test mode, all leds on
void max6952_test() {
output_low(MAX6952_CS);
spi_write(DISPLAY_TEST);
spi_write(DISPLAY_TEST_MODE);
output_high(MAX6952_CS);
}
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and this main file
| Code: | #include <18F4620.h>
#use delay(clock=20000000)
#fuses HS,NOWDT,NOBROWNOUT,NOPUT,NOLVP,DEBUG,NOSTVREN,NOPROTECT
#include <max6952.h>
void main() {
setup_spi(SPI_MASTER | SPI_H_TO_L | SPI_CLK_DIV_16);
max6952_test();
}
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Whats must i do to get it to work?
Please help |
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StuartH
Joined: 19 Aug 2005
Posts: 14
Location: W. Midlands, UK
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| Posted: Sun Mar 05, 2006 9:56 am |
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I posted some code for a MAX6953 under my old username quite a while back. That should illustrate the things you have to do.
It's been a long time since I used it and my copy of the datasheet is buried somewhere in my backups, but as I recall, the only real difference between the 6953 and 6952 is the processor interface. It's a fairly easy device to get working, provided that you actually read the datasheet properly before writing code. There are some traps for the unwary. |
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The Puma
Joined: 23 Apr 2004
Posts: 227
Location: The Netherlands
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| Posted: Sun Mar 05, 2006 10:38 am |
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@StuartH,
I have used your code
I have changed the i2c code to the hardware spi commands
but no luck, it did't work
With only the "DISPLAY_TEST" command all leds must be swiched on
but it did't
Why |
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StuartH
Joined: 19 Aug 2005
Posts: 14
Location: W. Midlands, UK
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| Posted: Sun Mar 05, 2006 1:14 pm |
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As I said, read the datasheet and look for the traps...
The device powers up in low power standby mode. Your code as it stands won't work because you don't make any attempt to enable the LED drivers first. I can't remember for sure, but I think the brightness is also set to minimum - i.e. invisible... Look at the short code snippet at the bottom of my MAX6953 post, and trace what it does. |
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The Puma
Joined: 23 Apr 2004
Posts: 227
Location: The Netherlands
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| Posted: Sun Mar 05, 2006 2:21 pm |
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| Is it possible to make a moving message board with the max6952? |
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