diff --git a/pico/lib/dma.py b/pico/lib/dma.py new file mode 100644 index 0000000..1abb96f --- /dev/null +++ b/pico/lib/dma.py @@ -0,0 +1,118 @@ +from machine import Pin +from rp2 import PIO, StateMachine, asm_pio +from time import sleep +import array +import uctypes +from uctypes import BF_POS, BF_LEN, UINT32, BFUINT32, struct + +PIO0_BASE = 0x50200000 +PIO1_BASE = 0x50300000 +DMA_BASE = 0x50000000 +DMA_CHAN_WIDTH = 0x40 +DMA_CHAN_COUNT = 12 + +DMA_SIZE_BYTE = 0x0 +DMA_SIZE_HALFWORD = 0x1 +DMA_SIZE_WORD = 0x2 + +# DMA: RP2040 datasheet 2.5.7 +DMA_CTRL_TRIG_FIELDS = { + "AHB_ERROR": 31<= 0 and sm_num < 4): + self.dma_chan.WRITE_ADDR_REG = PIO0_BASE + 0x10 + sm_num *4 + self.dma_chan.CTRL_TRIG.TREQ_SEL = sm_num + elif (sm_num < 8): + self.dma_chan.WRITE_ADDR_REG = PIO1_BASE + 0x10 + (sm_num-4) *4 + self.dma_chan.CTRL_TRIG.TREQ_SEL = sm_num + 4 + + if (block_size == 8): + self.dma_chan.CTRL_TRIG.DATA_SIZE = DMA_SIZE_BYTE + if (block_size == 16): + self.dma_chan.CTRL_TRIG.DATA_SIZE = DMA_SIZE_HALFWORD + if (block_size == 32): + self.dma_chan.CTRL_TRIG.DATA_SIZE = DMA_SIZE_WORD + + self.dma_chan.TRANS_COUNT_REG = transfer_count + + #Do I just always want these? + self.dma_chan.CTRL_TRIG.INCR_WRITE = 0 + self.dma_chan.CTRL_TRIG.INCR_READ = 1 + + def start_transfer(self, buffer, offset=0): + """Start DMA from buffer at byte offset (no copy; DMA reads from buffer + offset).""" + self.dma_chan.READ_ADDR_REG = uctypes.addressof(buffer) + offset + self.dma_chan.CTRL_TRIG.EN = 1 + + def transfer_count(self): + return self.dma_chan.TRANS_COUNT_REG + + def busy(self): + if self.dma_chan.CTRL_TRIG.DATA_SIZE == 1: + return True + else: + return False + + + + + + + + + + diff --git a/pico/lib/ws2812.py b/pico/lib/ws2812.py new file mode 100644 index 0000000..99a77e8 --- /dev/null +++ b/pico/lib/ws2812.py @@ -0,0 +1,83 @@ + +import array, time +from machine import Pin +import rp2 +from time import sleep +import dma + +@rp2.asm_pio(sideset_init=rp2.PIO.OUT_LOW, out_shiftdir=rp2.PIO.SHIFT_LEFT, autopull=True, pull_thresh=8) +def ws2812(): + T1 = 2 + T2 = 5 + T3 = 3 + wrap_target() + label("bitloop") + out(x, 1) .side(0) [T3 - 1] + jmp(not_x, "do_zero") .side(1) [T1 - 1] + jmp("bitloop") .side(1) [T2 - 1] + label("do_zero") + nop() .side(0) [T2 - 1] + wrap() + +class WS2812B: + BLACK = (0, 0, 0) + RED = (255, 0, 0) + YELLOW = (255, 150, 0) + GREEN = (0, 255, 0) + CYAN = (0, 255, 255) + BLUE = (0, 0, 255) + PURPLE = (180, 0, 255) + WHITE = (255, 255, 255) + COLORS = (BLACK, RED, YELLOW, GREEN, CYAN, BLUE, PURPLE, WHITE) + + def __init__(self, num_leds, pin, state_machine, brightness=0.1): + self.sm = rp2.StateMachine(state_machine, ws2812, freq=8_000_000, sideset_base=Pin(pin)) + self.sm.active(1) + self.ar = bytearray(num_leds * 3) + self.num_leds = num_leds + self.brightness = brightness + self.pio_dma = dma.PIO_DMA_Transfer(state_machine, state_machine, 8, num_leds * 3) + # Pre-built bytearrays, one per color (GRB, brightness applied) for fast show + self.color_buffers = [self._color_to_buffer(c) for c in self.COLORS] + + def _color_to_buffer(self, color): + """One bytearray of length num_leds*3, all pixels same color (GRB).""" + r, g, b = color[0], color[1], color[2] + g = int(g * self.brightness) & 0xFF + r = int(r * self.brightness) & 0xFF + b = int(b * self.brightness) & 0xFF + return bytearray([g, r, b] * self.num_leds) + + def show(self, buffer=None, offset=0): + """Push buffer to PIO via DMA. If buffer is None, use self.ar (offset must be 0). + With offset, DMA reads directly from buffer[offset:offset+num_leds*3]; no copy.""" + buf = buffer if buffer is not None else self.ar + self.pio_dma.start_transfer(buf, offset) + + def show_color(self, color_index): + """Show pre-built buffer for COLORS[color_index]. No fill() needed.""" + self.show(self.color_buffers[color_index]) + + def set(self, i, color): + self.ar[i*3] = int(color[1]*self.brightness) + self.ar[i*3+1] = int(color[0]*self.brightness) + self.ar[i*3+2] = int(color[2]*self.brightness) + + def fill(self, color): + for i in range(self.num_leds): + self.set(i, color) + + def busy(self): + return self.pio_dma.busy() + +if __name__ == "__main__": + num_leds, pin, sm, brightness = 10, 2, 0, 1 + ws0 = WS2812B(num_leds, pin, sm, brightness) + while True: + for color in ws0.COLORS: + ws0.fill(color) + ws0.show() + time.sleep(1) + + +