Create seesaw.py

Author: TheKitty

Crickit_microbit_MicroPython/seesaw.py

@@ -0,0 +1,111 @@
+# Adafruit Seesaw / CRICKIT driver for MicroPython
+# MIT License by Adafruit Industries Limor Fried
+# Copy onto the micro:bit with main.py using Mu Files icon
+from microbit import i2c
+import struct
+import time
+
+_SIGNALS = (2, 3, 40, 41, 11, 10, 9, 8)
+_PWMS = (14, 15, 16, 17, 19, 18, 22, 23, 42, 43, 12, 13)
+_SERVOS = (17, 16, 15, 14)
+_MOTORS = (22, 23, 19, 18)
+_DRIVES = (13, 12, 43, 42)
+_TOUCHES = (0, 1, 2, 3)
+_ADDR = 0x49
+
+reg_buf = bytearray(2)
+pwm_buf = bytearray(3)
+
+def _read(reghi, reglo, n, delay_s=0.01):
+    reg_buf[0] = reghi
+    reg_buf[1] = reglo
+    i2c.write(_ADDR, reg_buf)
+    time.sleep(delay_s)
+    return i2c.read(_ADDR, n)
+
+def _write(reghi, reglo, cmd):
+    reg_buf[0] = reghi
+    reg_buf[1] = reglo
+    #print("sswrite: ", [hex(i) for i in reg_buf+cmd])
+    i2c.write(_ADDR, reg_buf+cmd)
+
+# t is between 1 and 4
+def read_touch(t):
+    return struct.unpack(">H", _read(0x0F, 0x10+_TOUCHES[t-1], 2))[0]
+
+def pwm_write(pwm, val):
+    pwm_buf[0] = _PWMS.index(pwm)
+    pwm_buf[1] = val >> 8
+    pwm_buf[2] = val & 0xFF
+    _write(0x08, 0x01, pwm_buf)
+
+def set_pwmfreq(pwm, freq):
+    pwm_buf[0] = _PWMS.index(pwm)
+    pwm_buf[1] = freq >> 8
+    pwm_buf[2] = freq & 0xFF
+    _write(0x08, 0x02, pwm_buf)
+
+# signal is between 1 and 8
+def analog_read(signal):
+    return struct.unpack(">H", _read(0x09, 0x07+signal-1, 2))[0]
+
+def pin_config(pin, mode, pull=None, val=None):
+    if pin >= 32:
+        cmd = struct.pack(">I", 1 << (pin - 32))
+        cmd = bytearray(4) + cmd
+    else:
+        cmd = struct.pack(">I", 1 << pin)
+    if 0 <= mode <= 1:
+        _write(0x01, 0x03-mode, cmd)
+    if pull is not None and 0 <= pull <= 1:
+        _write(0x01, 0x0C-pull, cmd)
+    if val is not None and 0 <= val <= 1:
+        _write(0x01, 0x06-val, cmd)
+
+
+def init():
+    i2c.init()
+    while not _ADDR in i2c.scan():
+        print("Crickit not found!")
+        time.sleep(1)
+    reg_buf[0] = 0x7F
+    reg_buf[1] = 0xFF
+    i2c.write(_ADDR, reg_buf)
+
+# s is between 1 and 4
+def servo(s, degree, min=1.0, max=2.0):
+    set_pwmfreq(_SERVOS[s-1], 50)
+    val = 3276*min + (max-min)*3276*degree/180
+    pwm_write(_SERVOS[s-1], int(val))
+
+# d is between 1 and 4
+def drive(d, frac, freq=1000):
+    set_pwmfreq(_DRIVES[d-1], freq)
+    pwm_write(_DRIVES[d-1], int(frac*65535))
+
+# m is 1 or 2
+def motor(m, frac, freq=1000):
+    m -= 1  # start with 1
+    pin1,pin2 = _MOTORS[m*2:m*2+2]
+    set_pwmfreq(pin1, freq)
+    set_pwmfreq(pin2, freq)
+    if frac < 0:
+        pin1, pin2 = pin2, pin1
+    pwm_write(pin1, 0)
+    pwm_write(pin2, abs(int(frac*65535)))
+
+# signal is between 1 and 8, val is 0 or 1
+def write_digital(signal, val):
+    pin_config(_SIGNALS[signal-1], 1, 0, val) # output, pullup, value
+
+# signal is between 1 and 8
+def read_digital(signal):
+    pin = _SIGNALS[signal-1]
+    pin_config(pin, 0, 1, 1) # input, pullup, pullvalue
+    ret = _read(0x01, 0x04, 8)
+    b = 0
+    if pin > 32:
+        b = 4
+        pin -= 32
+    b += 3 - (pin // 8)
+    return (ret[b] & 1<<(pin % 8)) != 0