MM5450 LED Driver Coding

Jiyati

Hi Josh,

I'm driving 32 LEDs using Jameco's MM5450 chip. Here's the link to that chip's spec sheet.
I want to turn on the LEDs one after the other, serially, completing a loop within a minute. I don't know much about how to code in Spin, but this is what I came up with:

CON

  _clkmode      = xtal1+pll16x
  _xinfreq      = 5_000_000

  clk=1
  data=2
  'will add data neable later
OBJ

VAR


  long LightNum
  
PUB Main

  dira[noparse][[/noparse]clk]:=%10
  LightNum:=TurnLightOn
  waitcnt(clkfreq+cnt)

PUB TurnLightOn
repeat 32
  outa[noparse][[/noparse]clk]~~
  outa[noparse][[/noparse]clk]~
  LightBits:=(LightBits<<1)+ina[noparse][[/noparse]data]

I know I'm supposed to turn on the pins one after the other using outa[noparse][[/noparse]datapin], but I don't know where to do this... or am I already doing that with this code?
What do you think? Will this do the trick?

kwinn

If you want to turn on one led at a time you need to:

1 - Make sure the /data enable pin on the 5450 is low (could be tied always low)

2 - Set the serial data pin high

3 - Set the clock pin high, then back to low ( this lights led 34/35)

4 - wait for 1.875 seconds

5 - Set the serial data pin low

6 - Set the clock pin high, then back to low
7 - wait for 1.875 seconds

8 - Repeat 6 and 7 30 more times

Jiyati

ok so my new code is:

CON
  _clkmode      = xtal1+pll16x
  _xinfreq      = 5_000_000
  clk=1
  data=2
  'will add data enable later
OBJ

VAR
  long LightNum
  
PUB Main
  dira[noparse][[/noparse]clk]:=%1
  LightNum:=TurnLightOn
  waitcnt(clkfreq+cnt)

PUB TurnLightOn
  outa[noparse][[/noparse]data]~~
  outa[noparse][[/noparse]clk]~~
  outa[noparse][[/noparse]clk]~
  waitcnt(clkfreq*1.875+cnt)
  outa[noparse][[/noparse]data]~
  outa[noparse][[/noparse]clk]~~
repeat 30
  outa[noparse][[/noparse]clk]~
  waitcnt(clkfreq*1.875+cnt)
  LightBits:=(LightBits<<1)+ina[noparse][[/noparse]data]

but i tested this out and still, nothing is working. also i connected the data enable pin to ground and i hooked up the the brightness control pin to the power supply. are there any other corrections i could make?

pullmoll

Jiyati said...
ok so my new code is:

...
  dira[noparse][[/noparse]clk]:=%1
...

but i tested this out and still, nothing is working. also i connected the data enable pin to ground and i hooked up the the brightness control pin to the power supply. are there any other corrections i could make?

I see no dira[noparse][[/noparse]data] := 1 anywhere, so the data pin is input all the time!?

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