add sensor code

Author: simonbyrne

src/HTS221.jl

@@ -0,0 +1,95 @@
+# HTS221 humidity/temperature sensor.
+# See http://www.st.com/resource/en/datasheet/hts221.pdf
+
+const HTS221_t_coef  = Ref((NaN,NaN))
+const HTS221_h_coef  = Ref((NaN,NaN))
+
+function HTS221_calibrate()
+    setaddr(HTS221_ADDRESS)   
+    @assert smbus_read(0x0F) == 0xbc
+
+    ## read temp calibration data
+    # raw values
+    t0_raw = smbus_read_pair(0x3c)
+    t1_raw = smbus_read_pair(0x3e)
+
+    # known °C
+    u = smbus_read(0x35)
+    t0_C = Float64(Int16(u & 0b0011) << 8 | smbus_read(0x32))/8
+    t1_C = Float64(Int16(u & 0b1100) << 6 | smbus_read(0x33))/8
+    
+    m_t = (t1_C - t0_C)/(Float64(t1_raw) - Float64(t0_raw))
+    k_t = t1_C - m_t*t1_raw
+    HTS221_t_coef[] = (m_t, k_t)
+
+    ## read humidity calibration data
+    h0_raw = smbus_read_pair(0x36)
+    h1_raw = smbus_read_pair(0x3a)
+
+    h0_rH = Float64(smbus_read(0x30))/2
+    h1_rH = Float64(smbus_read(0x31))/2
+
+    m_h = (h1_rH - h0_rH)/(Float64(h1_raw) - Float64(h0_raw))
+    k_h = h1_rH - m_h*h1_raw
+    HTS221_h_coef[] = (m_h, k_h)
+
+    return nothing
+end
+
+function HTS221_raw_temp()
+    setaddr(HTS221_ADDRESS)
+    CTRL_REG1 = 0x20
+    CTRL_REG2 = 0x21
+    
+    smbus_write(CTRL_REG1, 0x00) # power down
+    smbus_write(CTRL_REG1, 0x84) # power on, block update
+    smbus_write(CTRL_REG2, 0x01) # one-shot aquisition
+
+    while true
+        sleep(0.025)
+        smbus_read(CTRL_REG2) == 0 && break # check if finished
+    end
+    t_raw = smbus_read_pair(0x2a)
+    smbus_write(CTRL_REG1, 0x00) # power down
+    return t_raw
+end
+
+function HTS221_raw_humidity()
+    setaddr(HTS221_ADDRESS)
+    CTRL_REG1 = 0x20
+    CTRL_REG2 = 0x21
+    
+    smbus_write(CTRL_REG1, 0x00) # power down
+    smbus_write(CTRL_REG1, 0x84) # power on, block update
+    smbus_write(CTRL_REG2, 0x01) # one-shot aquisition
+
+    while true
+        sleep(0.025)
+        smbus_read(CTRL_REG2) == 0 && break # check if finished
+    end
+    h_raw = smbus_read_pair(0x28)
+    smbus_write(CTRL_REG1, 0x00) # power down
+    return h_raw
+end
+
+"""
+    HTS221_temperature()
+
+The temperature (in °C) from the HTS221 sensor.
+"""
+function HTS221_temperature()
+    (m_t, k_t) = HTS221_t_coef[]
+    t_raw = HTS221_raw_temp()
+    m_t*t_raw + k_t
+end
+
+"""
+    HTS221_humidity()
+
+The relative humidity (as a percentage) from the HTS221 sensor.
+"""
+function HTS221_humidity()
+    (m_h, k_h) = HTS221_h_coef[]
+    h_raw = HTS221_raw_humidity()
+    m_h*h_raw + k_h
+end

src/LPS25H.jl

@@ -0,0 +1,54 @@
+# LPS25H pressure/temperature sensor
+# See http://www.st.com/resource/en/datasheet/lps25h.pdf
+
+"""
+    LPS25H_pressure()
+
+The atmospheric pressure (in millibars) from the LPS25H sensor.
+"""
+function LPS25H_pressure()
+    setaddr(LPS25H_ADDRESS)
+    CTRL_REG1 = 0x20
+    CTRL_REG2 = 0x21
+
+    smbus_write(CTRL_REG1, 0x00) # power down
+    smbus_write(CTRL_REG1, 0x84) # power on, block update
+    smbus_write(CTRL_REG2, 0x01) # one-shot aquisition
+
+    while true
+        sleep(0.025)
+        smbus_read(CTRL_REG2) == 0 && break # check if finished
+    end
+
+    pressure = (Int32(smbus_read(0x2a)) << 16 | Int16(smbus_read(0x29)) << 8 | smbus_read(0x28)) / 4096
+
+    smbus_write(CTRL_REG1, 0x00) # power down
+    return pressure
+end
+
+"""
+    HTS221_temperature()
+
+The temperature (in °C) from the LPS25H sensor.
+"""
+function LPS25H_temperature()
+    setaddr(LPS25H_ADDRESS)
+    CTRL_REG1 = 0x20
+    CTRL_REG2 = 0x21
+
+    smbus_write(CTRL_REG1, 0x00) # power down
+    smbus_write(CTRL_REG1, 0x84) # power on, block update
+    smbus_write(CTRL_REG2, 0x01) # one-shot aquisition
+
+    while true
+        sleep(0.025)
+        smbus_read(CTRL_REG2) == 0 && break # check if finished
+    end
+
+    temp = 42.5 + (Int16(smbus_read(0x2c)) << 8 | smbus_read(0x2b)) / 480
+
+    smbus_write(CTRL_REG1, 0x00) # power down
+    return temp
+end
+
+

src/SenseHat.jl

@@ -2,7 +2,11 @@ __precompile__()
 module SenseHat
 
 export led_matrix, RGB565,
-    Stick, StickEvent, sticktask, readstick
+    Stick, StickEvent, sticktask, readstick,
+    pressure, temperature, humidity
+
+
+include("ioctl.jl")
 
 include("led.jl")
 using .LED
@@ -11,4 +15,7 @@ include("led_extra.jl")
 include("stick.jl")
 using .Stick
 
+include("sensors.jl")
+using .Sensors
+
 end # module

src/ioctl.jl

@@ -0,0 +1,37 @@
+"""
+    ioctl(f, request, arg)
+
+A wrapper around the unix `ioctl` function:
+
+- `f` should be either a file descriptor (a `Cint`), an `IOStream` or a `File` object
+
+- `request` is a request code
+
+- `arg` is either an integer (which will be passed as a `Cint`), or a buffer (which will
+  be passed as a `Ptr{Void}`).
+
+Will throw a `SystemError` if an error occurs. Otherwise returns a `Cint` (which is
+typically, though not always, 0).
+
+"""
+function ioctl end
+
+
+function ioctl(fd::Cint, request::Integer, arg::Integer)
+    ret = ccall(:ioctl, Cint, (Cint, Culong, Cint...), fd, request, arg)
+    if ret < 0
+        throw(SystemError("ioctl error"))
+    end
+    return ret
+end
+function ioctl(fd::Cint, request::Integer, arg)
+    ret = ccall(:ioctl, Cint, (Cint, Culong, Ptr{Void}...), fd, request, arg)
+    if ret < 0
+        throw(SystemError("ioctl error"))
+    end
+    return ret
+end
+
+ioctl(f::Union{Base.Filesystem.File, IOStream}, request::Integer, arg) =
+    ioctl(fd(f), request, arg)
+    

src/led.jl

@@ -1,4 +1,7 @@
 module LED
+
+import ..ioctl
+
 export led_matrix, RGB565
 
 using ColorTypes, FixedPointNumbers
@@ -18,7 +21,13 @@ function _led_fb_device()
     error("Sense Hat not found.")
 end
 
-const LED_FB_DEVICE = _led_fb_device()
+const LED_FB_DEVICE_PATH = _led_fb_device()
+const LED_FB_DEVICE = Ref{IOStream}()
+
+function __init__()
+    LED_FB_DEVICE[] = open(LED_FB_DEVICE_PATH,"w+")
+end
+
 
 
 typealias U5 UFixed{UInt8,5}
@@ -45,6 +54,8 @@ ColorTypes.blue(c::RGB565) = U5(c.data & 0x1f, Val{true})
 ColorTypes.ccolor{Csrc<:Colorant}(::Type{RGB565}, ::Type{Csrc}) = RGB565
 ColorTypes.base_color_type(::Type{RGB565}) = RGB565
 
+
+
 """
     led_matrix()
 
@@ -55,6 +66,7 @@ arrays), it is generally preferable to assign it once into a `const` variable so
 minimise the number of open file handlers.
 
 # Example
+
 ```
 using SenseHat
 using ColorTypes
@@ -67,7 +79,52 @@ LED[:] = RGB(0,0,0)
 ```
 
 """
-led_matrix() = Mmap.mmap(LED_FB_DEVICE, Array{RGB565,2}, (8,8); grow=false)
+led_matrix() = Mmap.mmap(LED_FB_DEVICE[], Array{RGB565,2}, (8,8); grow=false)
+
+
+
+
+const FBIO_GET_GAMMA = 61696
+const FBIO_SET_GAMMA = 61697
+const FBIO_RESET_GAMMA = 61698
+
+@enum(GammaScale, GAMMA_DEFAULT, GAMMA_LOW, GAMMA_USER)
+
+"""
+    getgamma()
+
+Return the current gamma correction table for the Sense HAT LED matrix, as a vector of 32
+`UFixed{UInt8,5}` numbers.
+
+"""
+function getgamma()
+    buffer = zeros(UInt8, 32)
+    ioctl(LED_FB_DEVICE[], FBIO_GET_GAMMA, buffer)
+    return buffer
+end
+
+"""
+    setgamma(v::GammaScale)
+    setgamma(table::Vector)
+
+Set the gamma correction for the Sense HAT LED matrix. This can either be one of the
+predefined settings (`GAMMA_DEFAULT`, `GAMMA_LOW`, `GAMMA_USER`) or a table of values
+between 0 and 1 (the actual values will be converted to `UFixed{UInt8, 5}`).
+
+"""
+function setgamma end
+
+function setgamma(v::GammaScale)
+    ioctl(LED_FB_DEVICE[], FBIO_RESET_GAMMA, Cint(v))
+    return nothing
+end
+
+function setgamma(table::Vector{U5})
+    length(table) == 32 || error("Table must contain 32 values.")
+    ioctl(LED_FB_DEVICE[], FBIO_SET_GAMMA, table)
+    return nothing
+end
+setgamma(table::AbstractVector) = setgamma(convert(Vector{U5}, table))
 
 
 

src/sensors.jl

@@ -0,0 +1,53 @@
+module Sensors
+export humidity, temperature, pressure
+
+
+const I2C_DEVICE_PATH = "/dev/i2c-1"
+const I2C_DEVICE = Ref{IOStream}()
+const I2C_ADDR = Ref{UInt8}(0xff)
+
+function __init__()
+    I2C_DEVICE[] = open("/dev/i2c-1","r+")
+    HTS221_calibrate()
+end
+
+import ..ioctl
+include("smbus.jl")
+
+const LPS25H_ADDRESS = 0x5c # Pressure/temp
+const HTS221_ADDRESS = 0x5f # Humidity/temp
+
+function setaddr(addr::UInt8)
+    if I2C_ADDR[] != addr
+        ioctl(I2C_DEVICE[], I2C_SLAVE, addr)
+        I2C_ADDR[] = addr
+    end
+end
+
+include("HTS221.jl")
+include("LPS25H.jl")
+
+
+"""
+    humidity()
+
+The relative humidity (as a percentage between 0 and 100).
+"""
+humidity()    = HTS221_humidity()
+
+"""
+    temperature()
+
+The temperature (in °C).
+"""
+temperature() = HTS221_temperature()
+
+"""
+    pressure()
+
+The atmospheric pressure (in millibars).
+"""
+pressure()    = LPS25H_pressure()
+
+
+end # module

src/smbus.jl

@@ -0,0 +1,40 @@
+# A basic implementation of the SMBus interface
+# Based on the i2c-dev.h (the header only "static inline" version from i2c-tools)
+
+const I2C_SMBUS_READ  = 0x01
+const I2C_SMBUS_WRITE = 0x00
+
+const I2C_SMBUS_BYTE       = 0x01
+const I2C_SMBUS_BYTE_DATA  = 0x02
+
+const I2C_SLAVE  = 0x0703
+const I2C_SMBUS  = 0x0720
+
+immutable SMBusData
+    read_write ::UInt8
+    command    ::UInt8
+    size       ::UInt32
+    data       ::Ptr{UInt8}
+end
+
+function smbus_read(cmd::UInt8)
+    buffer = Ref(UInt8(0))
+    data = SMBusData(I2C_SMBUS_READ, cmd, I2C_SMBUS_BYTE_DATA,
+                     Base.unsafe_convert(Ptr{UInt8}, buffer))
+    ioctl(I2C_DEVICE[], I2C_SMBUS, Ref(data))
+    return buffer[]
+end
+function smbus_read_pair(cmd::UInt8)
+    lo = smbus_read(cmd)
+    hi = smbus_read(cmd+UInt8(1))
+    return Int16(hi)<<8 | lo
+end
+
+function smbus_write(cmd::UInt8, val::UInt8)
+    buffer = Ref(val)
+    data = SMBusData(I2C_SMBUS_WRITE, cmd, I2C_SMBUS_BYTE_DATA,
+                     Base.unsafe_convert(Ptr{UInt8}, buffer))
+    ioctl(I2C_DEVICE[], I2C_SMBUS, Ref(data))
+    return 1
+end
+