machine/microbit-v2: add initial support based on work done by @alankrantas thank you!

Signed-off-by: deadprogram <ron@hybridgroup.com>

src/machine/machine_nrf52833.go

@@ -0,0 +1,89 @@
+// +build nrf52833
+
+package machine
+
+import (
+	"device/nrf"
+)
+
+// Hardware pins
+const (
+	P0_00 Pin = 0
+	P0_01 Pin = 1
+	P0_02 Pin = 2
+	P0_03 Pin = 3
+	P0_04 Pin = 4
+	P0_05 Pin = 5
+	P0_06 Pin = 6
+	P0_07 Pin = 7
+	P0_08 Pin = 8
+	P0_09 Pin = 9
+	P0_10 Pin = 10
+	P0_11 Pin = 11
+	P0_12 Pin = 12
+	P0_13 Pin = 13
+	P0_14 Pin = 14
+	P0_15 Pin = 15
+	P0_16 Pin = 16
+	P0_17 Pin = 17
+	P0_18 Pin = 18
+	P0_19 Pin = 19
+	P0_20 Pin = 20
+	P0_21 Pin = 21
+	P0_22 Pin = 22
+	P0_23 Pin = 23
+	P0_24 Pin = 24
+	P0_25 Pin = 25
+	P0_26 Pin = 26
+	P0_27 Pin = 27
+	P0_28 Pin = 28
+	P0_29 Pin = 29
+	P0_30 Pin = 30
+	P0_31 Pin = 31
+	P1_00 Pin = 32
+	P1_01 Pin = 33
+	P1_02 Pin = 34
+	P1_03 Pin = 35
+	P1_04 Pin = 36
+	P1_05 Pin = 37
+	P1_06 Pin = 38
+	P1_07 Pin = 39
+	P1_08 Pin = 40
+	P1_09 Pin = 41
+	P1_10 Pin = 42
+	P1_11 Pin = 43
+	P1_12 Pin = 44
+	P1_13 Pin = 45
+	P1_14 Pin = 46
+	P1_15 Pin = 47
+)
+
+var (
+	UART0 = NRF_UART0
+)
+
+// Get peripheral and pin number for this GPIO pin.
+func (p Pin) getPortPin() (*nrf.GPIO_Type, uint32) {
+	if p >= 32 {
+		return nrf.P1, uint32(p - 32)
+	} else {
+		return nrf.P0, uint32(p)
+	}
+}
+
+func (uart UART) setPins(tx, rx Pin) {
+	nrf.UART0.PSEL.TXD.Set(uint32(tx))
+	nrf.UART0.PSEL.RXD.Set(uint32(rx))
+}
+
+func (i2c I2C) setPins(scl, sda Pin) {
+	i2c.Bus.PSEL.SCL.Set(uint32(scl))
+	i2c.Bus.PSEL.SDA.Set(uint32(sda))
+}
+
+// PWM
+var (
+	pwmChannelPins     = [4]uint32{0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF}
+	pwms               = [4]*nrf.PWM_Type{nrf.PWM0, nrf.PWM1, nrf.PWM2, nrf.PWM3}
+	pwmChannelSequence [4]uint16
+)