mirror of
https://github.com/tinygo-org/drivers.git
synced 2026-07-26 10:38:41 +00:00
Daniel Esteban
91 lines
2.1 KiB
Go
91 lines
2.1 KiB
Go
package adt7410
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import (
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"machine"
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"time"
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)
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type Error uint8
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const (
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ErrInvalidID Error = 0x1
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)
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func (e Error) Error() string {
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switch e {
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case ErrInvalidID:
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return "Invalid chip ID"
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default:
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return "Unknown error"
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}
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}
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type Device struct {
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bus *machine.I2C
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buf []byte
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addr uint8
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}
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// New returns ADT7410 device for the provided I2C bus and address. The ADT7410
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// has a default address of 0x48 (1001000). The last 2 bits of the address
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// can be set using by connecting to the A1 and A0 pins to VDD or GND (for a
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// total of up to 4 devices on a I2C bus). Also note that 10k pullups are
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// recommended for the SDA and SCL lines.
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func New(i2c *machine.I2C, addressBits uint8) *Device {
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return &Device{
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bus: i2c,
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buf: make([]byte, 2),
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addr: Address | (addressBits & 0x3),
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}
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}
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func (dev *Device) Configure() (err error) {
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// verify the chip ID
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// TODO: According to datasheet, the check below should work; however
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// this does not seem to be working right, but is not exactly
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// necessary, so can revisit later to see if there is a bug
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//id := dev.ReadByte(RegID) & 0xF8
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//if id != 0xC8 {
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// err = ErrInvalidID
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//}
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// reset the chip
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dev.writeByte(RegReset, 0xFF)
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time.Sleep(10 * time.Millisecond)
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return
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}
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// ReadTemperature returns the temperature in celsius milli degrees (°C/1000)
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func (d *Device) ReadTemperature() (temperature int32, err error) {
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return (int32(d.readUint16(RegTempValueMSB)) * 1000) / 128, nil
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}
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// ReadTempC returns the value in the temperature value register, in Celcius
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func (d *Device) ReadTempC() float32 {
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t := d.readUint16(RegTempValueMSB)
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return float32(int(t)) / 128.0
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}
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// ReadTempF returns the value in the temperature value register, in Fahrenheit
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func (d *Device) ReadTempF() float32 {
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return d.ReadTempC()*1.8 + 32.0
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}
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func (d *Device) writeByte(reg uint8, data byte) {
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d.buf[0] = reg
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d.buf[1] = data
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d.bus.Tx(uint16(d.addr), d.buf, nil)
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}
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func (d *Device) readByte(reg uint8) byte {
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d.bus.ReadRegister(d.addr, reg, d.buf)
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return d.buf[0]
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}
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func (d *Device) readUint16(reg uint8) uint16 {
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d.bus.ReadRegister(d.addr, reg, d.buf)
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return uint16(d.buf[0])<<8 | uint16(d.buf[1])
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}
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