From 4bd873a82dd8f7a5154ce26f9cb951b9e98bad5a Mon Sep 17 00:00:00 2001
From: soypat <graded.sp@gmail.com>
Date: Tue, 26 Dec 2023 15:00:56 -0800
Subject: [PATCH] add draft apds9930

---
 apds9930/apds9930.go                     | 68 ++++++++++++++++++++++++
 apds9930/registers.go                    | 19 +++++++
 examples/apds9930/proximity/proximity.go | 39 ++++++++++++++
 3 files changed, 126 insertions(+)
 create mode 100644 apds9930/apds9930.go
 create mode 100644 apds9930/registers.go
 create mode 100644 examples/apds9930/proximity/proximity.go

diff --git a/apds9930/apds9930.go b/apds9930/apds9930.go
new file mode 100644
index 0000000..1e59d79
--- /dev/null
+++ b/apds9930/apds9930.go
@@ -0,0 +1,68 @@
+package apds9930
+
+import "tinygo.org/x/drivers"
+
+type Dev struct {
+	bus    drivers.I2C
+	_txerr error
+	addr   uint16
+	buf    [8]byte
+}
+
+func New(bus drivers.I2C, addr uint8) Dev {
+	return Dev{bus: bus, addr: uint16(addr)}
+}
+
+func (d *Dev) Init() error {
+	d.txNew()
+	d.txWrite8(regENABLE, 0x00) // disable all features.
+	d.txWrite8(regATIME, 0xee)  // set default integration time.
+	d.txWrite8(regPPULSE, 0x04)
+	d.txWrite8(regWTIME, 0xee) // set default wait time.
+	d.txWrite8(regPTIME, 0xff) // set default pulse count.
+	d.txWrite8(regCONTROL, 0x20)
+	return d.txErr()
+}
+
+func (d *Dev) EnableProximity() error {
+	d.txNew()
+	d.txWrite8(regENABLE, 8|4|2|1)
+	return d.txErr()
+}
+
+func (d *Dev) ProximityAvailable() bool {
+	d.txNew()
+	return d.txRead8(regSTATUS)&0x20 == 1
+}
+
+func (d *Dev) ReadProximity() uint8 {
+	d.txNew()
+	h := d.txRead8(regPDATAH)
+	l := d.txRead8(regPDATAL)
+	if d.txErr() != nil {
+		return 0
+	}
+	return (h << 8) | l
+}
+
+func (d *Dev) txRead8(reg uint8) uint8 {
+	if d.txErr() != nil {
+		return 0
+	}
+	d.buf[0] = reg | 0xa0
+	d._txerr = d.bus.Tx(d.addr, d.buf[:1], d.buf[1:2])
+	return d.buf[1]
+}
+
+func (d *Dev) txWrite8(reg uint8, val uint8) {
+	if d.txErr() != nil {
+		return
+	}
+	d.buf[0] = reg | 0x80
+	d.buf[1] = val
+	d._txerr = d.bus.Tx(d.addr, d.buf[:2], nil)
+}
+
+func (d *Dev) txNew() { d._txerr = nil }
+
+func (d *Dev) txErr() error { return d._txerr }
diff --git a/apds9930/registers.go b/apds9930/registers.go
new file mode 100644
index 0000000..79587e5
--- /dev/null
+++ b/apds9930/registers.go
@@ -0,0 +1,19 @@
+package apds9930
+
+const (
+	regENABLE  = 0x00
+	regATIME   = 0x01
+	regPTIME   = 0x02
+	regWTIME   = 0x03
+	regPILTL   = 0x08
+	regPILTH   = 0x09
+	regPIHTL   = 0x0A
+	regPIHTH   = 0x0B
+	regCONFIG  = 0x0D
+	regPPULSE  = 0x0E
+	regCONTROL = 0x0F
+	regSTATUS  = 0x13
+	regPDATAL  = 0x18
+	regPDATAH  = 0x19
+	regPOFFSET = 0x1E
+)
diff --git a/examples/apds9930/proximity/proximity.go b/examples/apds9930/proximity/proximity.go
new file mode 100644
index 0000000..e7861b1
--- /dev/null
+++ b/examples/apds9930/proximity/proximity.go
@@ -0,0 +1,39 @@
+package main
+
+import (
+	"machine"
+	"time"
+
+	"tinygo.org/x/drivers/apds9930"
+)
+
+func main() {
+	// Sleep to catch any errors through the serial monitor.
+	time.Sleep(1000 * time.Millisecond)
+	bus := machine.I2C0
+	// use Nano 33 BLE Sense's internal I2C bus
+	err := bus.Configure(machine.I2CConfig{
+		SCL:       machine.GP1,
+		SDA:       machine.GP0,
+		Frequency: 100 * machine.KHz,
+	})
+	if err != nil {
+		panic(err.Error())
+	}
+	sensor := apds9930.New(bus, 0x39)
+
+	err = sensor.Init()
+	if err != nil {
+		panic(err)
+	}
+	err = sensor.EnableProximity()
+	if err != nil {
+		panic(err)
+	}
+	println("proximity enabled!")
+	for {
+		time.Sleep(50 * time.Millisecond)
+		prox := sensor.ReadProximity()
+		println("proximity:", prox)
+	}
+}