2 replies to this topic

[ninoq]

I'm interested in using SPI on a mini to drive a HL1606 RGB LED strip. I'd appreciate any advice and/or example code.

[Stefan]

Hi ninoq, I looked for you, first hit I had was: http://tuney.blogspo...ing-system.html Hope it helps!

[ninoq]

Thanks Stefan. As it turns out I gave up may be too easily on trying to use the NMF SPI class because I wasn't sure how to access it to find out why it wasn't working in my application. Instead I tried bit banging and got it to work almost straightaway - see code below. What are the pros and cons of bit banging as opposed to using the NMF SPI class? Is there a guide on how to access and customise the NMF firmware? ninoq //**************************************************************************************************************** private static void LEDStripper1(byte controlON, byte controlOFF, uint LEDIndxFirst, uint LEDIndxLast) { //Turns on LEDS in strip from LED[LEDIndxStart] to LED[LEDIndxEnd] incl. //NB. assumes argument validity checked in calling routine and that all LEDS are off //Warning: may not work with all strips - you may need to consult strip's data sheet and experiment. //Arguments: //controlON - control byte to turn on LED - refer to the LED strip's data sheet; //controlOFF - control byte to turn off LED - refer to the LED strip's data sheet; //LEDIndxFirst - index of first LED to be turned on; and //LEDIndxLast - index of last LED to be turned on. //GPIO pins: //"mosi" - configured for output with intial state low - sends bits to strip; //"spck"- configured for output with intial state low - clock pin; and //"ss" - configured for output with intial state high - latch pin. byte control; //send "on/off" control bytes for (uint j = LEDIndxLast; j > 0; j--) { if (j >= LEDIndxFirst) control = controlON; else control = controlOFF; ss.Write(false); //set latch low //send control byte bits - MSB first for (int i = 0; i < 8; i++) { mosi.Write((byte)(control & 0x80) == 0x80);//masks out and sends bit 7 spck.Write(true);//set clock pin high spck.Write(false);//set clock pin low control = (byte)((int)control << 1);//left shift 1 bit Thread.Sleep(1); } } ss.Write(true);//write data to strip } //******************************************************************************************************************