Chapter 6 code

ch-6/2-techniques/pio_counting_up.py

@@ -0,0 +1,39 @@
+"""Count down"""
+import rp2pio
+import adafruit_pioasm
+import array
+
+
+program = """
+.program counting_up    
+    set y, 21       ; set a value in y
+    ; now send it to be printed
+    mov isr, y
+    push noblock    ; and use PUSH to put it on the receive FIFO
+    
+    ; Add 1
+    mov y, ~ y      ; invert it
+    jmp y--, fake    ; subtract from it
+fake:
+    mov isr, ~ y
+
+    push noblock    ; and use PUSH to put it on the receive FIFO
+"""
+
+assembled = adafruit_pioasm.assemble(program)
+
+## set up a statemachine
+sm = rp2pio.StateMachine(
+    assembled,
+    frequency=2000,
+)
+
+buffer = array.array('I', [0])
+
+# read the data
+sm.readinto(buffer)
+print("Before {0} 0b{0:08b} 0x{0:x}".format(buffer[0]))
+
+# read the data
+sm.readinto(buffer)
+print("After {0} 0b{0:08b} 0x{0:x}".format(buffer[0]))