fixup! Add HTS221 sensor temperature read

Author: mathk

drivers/sensor/HTS221.zig

@@ -7,6 +7,7 @@
 //!
 const std = @import("std");
 const mdf_base = @import("../framework.zig").base;
+const InterfaceError = mdf_base.I2C_Device.InterfaceError;
 
 const assert = std.debug.assert;
 
@@ -67,7 +68,7 @@ pub const HTS221 = struct {
         T_OUT = 0x2A,
         STATUS_REG = 0x27,
 
-        // Callibration register
+        // Calibration register
         T0_DEGC_X8 = 0x32,
         T1_DEGC_X8 = 0x33,
         T01_DEGC_MSB_x8 = 0x35,
@@ -131,83 +132,96 @@ pub const HTS221 = struct {
         reserved0: u2,
     });
 
+    const T01_DEGC_MSB = Reg(packed struct(u8) {
+        T0MSB: i2,
+        T1MSB: i2,
+        reserved0: u4,
+    });
+
     dev: *mdf_base.I2C_Device,
 
-    // Needs to be initialize with calibration value.
+    // Needs to be initialized with calibration value.
     t_slop: f32 = 0.0,
     t_b0: f32 = 0.0,
 
     // internal read buffer
-    read_buffer: [2]u8 = [2]u8{ 0, 0 },
+    read_buffer: [2]u8 = .{ 0, 0 },
+
+    fn read_one_byte(self: *@This(), register: RegsAddr) InterfaceError!u8 {
+        try self.dev.write_then_read(address, &[_]u8{register.v()}, self.read_buffer[0..1]);
+        return self.read_buffer[0];
+    }
+
+    // LSB is always read first.
+    fn read_two_byte(self: *@This(), register: RegsAddr) InterfaceError!u16 {
+        try self.dev.write_then_read(address, &[_]u8{register.auto_v()}, &self.read_buffer);
+        return @as(u16, @intCast(self.read_buffer[0])) | (@as(u16, @intCast(self.read_buffer[1])) << 8);
+    }
 
-    fn init_temp_callibration(self: *@This()) !void {
+    fn init_temp_calibration(self: *@This()) InterfaceError!void {
         // Get the MSB of degC calibration value.
-        try self.dev.write_then_read(address, &[_]u8{RegsAddr.T01_DEGC_MSB_x8.v()}, self.read_buffer[0..1]);
-        const t0msb = @as(i10, @intCast(@as(i2, @bitCast(@as(u2, @truncate(self.read_buffer[0])))))) << 8;
-        const t1msb = @as(i10, @intCast(@as(i2, @bitCast(@as(u2, @truncate(self.read_buffer[0] >> 2)))))) << 8;
+        const t01_msb_reg = T01_DEGC_MSB.from(try self.read_one_byte(RegsAddr.T01_DEGC_MSB_x8));
+        const t0msb = @as(i10, @intCast(t01_msb_reg.read().T0MSB)) << 8;
+        const t1msb = @as(i10, @intCast(t01_msb_reg.read().T1MSB)) << 8;
 
-        try self.dev.write_then_read(address, &[_]u8{RegsAddr.T0_DEGC_X8.v()}, self.read_buffer[0..1]);
-        const t0_deg = @as(f32, @floatFromInt(@as(i10, @bitCast(@as(u10, @intCast(self.read_buffer[0])))) | t0msb)) / 8.0;
+        const t0_degc_lsb = @as(u10, @intCast(try self.read_one_byte(RegsAddr.T0_DEGC_X8)));
+        const t0_deg = @as(f32, @floatFromInt(@as(i10, @bitCast(t0_degc_lsb)) | t0msb)) / 8.0;
 
-        try self.dev.write_then_read(address, &[_]u8{RegsAddr.T1_DEGC_X8.v()}, self.read_buffer[0..1]);
-        const t1_deg = @as(f32, @floatFromInt(@as(i10, @bitCast(@as(u10, @intCast(self.read_buffer[0])))) | t1msb)) / 8.0;
+        const t1_degc_lsb = @as(u10, @intCast(try self.read_one_byte(RegsAddr.T1_DEGC_X8)));
+        const t1_deg = @as(f32, @floatFromInt(@as(i10, @bitCast(t1_degc_lsb)) | t1msb)) / 8.0;
 
-        try self.dev.write_then_read(address, &[_]u8{RegsAddr.T0_OUT.auto_v()}, &self.read_buffer);
-        const T0 = @as(f32, @floatFromInt(@as(i16, @intCast(self.read_buffer[0])) | (@as(i16, @intCast(self.read_buffer[1])) << 8)));
+        const t0_raw = try self.read_two_byte(RegsAddr.T0_OUT);
+        const T0 = @as(f32, @floatFromInt(@as(i16, @bitCast(t0_raw))));
 
-        try self.dev.write_then_read(address, &[_]u8{RegsAddr.T1_OUT.auto_v()}, &self.read_buffer);
-        const T1 = @as(f32, @floatFromInt(@as(i16, @intCast(self.read_buffer[0])) | (@as(i16, @intCast(self.read_buffer[1])) << 8)));
+        const t1_raw = try self.read_two_byte(RegsAddr.T1_OUT);
+        const T1 = @as(f32, @floatFromInt(@as(i16, @bitCast(t1_raw))));
 
         self.t_slop = ((t1_deg - t0_deg) / (T1 - T0));
         self.t_b0 = t0_deg - T0 * self.t_slop;
     }
 
-    fn setup_output_rate(self: *@This(), rate: ODR) !void {
-        try self.dev.write_then_read(address, &[_]u8{RegsAddr.CTRL_REG1.v()}, self.read_buffer[0..1]);
-        var reg = CTRL_REG1.from(self.read_buffer[0]);
+    fn setup_output_rate(self: *@This(), rate: ODR) InterfaceError!void {
+        var reg = CTRL_REG1.from(try self.read_one_byte(RegsAddr.CTRL_REG1));
         reg.modify(.{ .ODR = rate });
         try self.dev.write(address, &[_]u8{ RegsAddr.CTRL_REG1.v(), reg.raw });
     }
 
-    fn setup_average(self: *@This(), avgt: AVGT, avgh: AVGH) !void {
-        try self.dev.write_then_read(address, &[_]u8{RegsAddr.AV_CONF.v()}, self.read_buffer[0..1]);
-        var reg = AV_CONF.from(self.read_buffer[0]);
+    fn setup_average(self: *@This(), avgt: AVGT, avgh: AVGH) InterfaceError!void {
+        var reg = AV_CONF.from(try self.read_one_byte(RegsAddr.AV_CONF));
         reg.modify(.{
             .AVGH = avgh,
             .AVGT = avgt,
         });
         try self.dev.write(address, &[_]u8{ RegsAddr.AV_CONF.v(), reg.raw });
     }
 
-    pub fn turn_on(self: *@This()) !void {
-        try self.dev.write_then_read(address, &[_]u8{RegsAddr.CTRL_REG1.v()}, self.read_buffer[0..1]);
-        var reg = CTRL_REG1.from(self.read_buffer[0]);
+    pub fn turn_on(self: *@This()) InterfaceError!void {
+        var reg = CTRL_REG1.from(try self.read_one_byte(RegsAddr.CTRL_REG1));
         reg.modify(.{ .PD = 1 });
         try self.dev.write(address, &[_]u8{ RegsAddr.CTRL_REG1.v(), reg.raw });
     }
 
-    pub fn turn_off(self: *@This()) !void {
-        try self.dev.write_then_read(address, &[_]u8{RegsAddr.CTRL_REG1.v()}, self.read_buffer[0..1]);
-        var reg = CTRL_REG1.from(self.read_buffer[0]);
+    pub fn turn_off(self: *@This()) InterfaceError!void {
+        var reg = CTRL_REG1.from(try self.read_one_byte(RegsAddr.CTRL_REG1));
         reg.modify(.{ .PD = 0 });
         try self.dev.write(address, &[_]u8{ RegsAddr.CTRL_REG1.v(), reg.raw });
     }
 
-    pub fn configure(self: *@This(), config: Config) !void {
-        try self.init_temp_callibration();
+    pub fn configure(self: *@This(), config: Config) InterfaceError!void {
+        try self.init_temp_calibration();
         try self.setup_output_rate(config.outputDataRate);
         try self.setup_average(config.temperatureAverageSample, config.humidityAverageSample);
     }
 
-    pub fn temperature_ready(self: *@This()) !bool {
-        try self.dev.write_then_read(address, &[_]u8{RegsAddr.STATUS_REG.v()}, self.read_buffer[0..1]);
-        const status = STATUS_REG.from(self.read_buffer[0]);
+    pub fn temperature_ready(self: *@This()) InterfaceError!bool {
+        const raw_status = try self.read_one_byte(RegsAddr.STATUS_REG);
+        const status = STATUS_REG.from(raw_status);
         return status.read().T_DA == 1;
     }
 
-    pub fn read_temperature(self: *@This()) !f32 {
-        try self.dev.write_then_read(address, &[_]u8{RegsAddr.T_OUT.auto_v()}, &self.read_buffer);
-        const inter = @as(f32, @floatFromInt(@as(i16, @intCast(self.read_buffer[0])) | (@as(i16, @intCast(self.read_buffer[1])) << 8)));
+    pub fn read_temperature(self: *@This()) InterfaceError!f32 {
+        const raw_t = try self.read_two_byte(RegsAddr.T_OUT);
+        const inter = @as(f32, @floatFromInt(@as(i16, @bitCast(raw_t))));
         return self.t_b0 + inter * self.t_slop;
     }
 

examples/stmicro/stm32/src/stm32f303/hts221.zig

@@ -33,7 +33,6 @@ pub noinline fn main() !void {
         },
     }).apply();
 
-    // // I2C1 is the magnetometer on pin PB6/7
     var i2c1 = stm32.i2c.I2CDevice.init(.I2C1);
     try i2c1.apply();
     var device = i2c1.as_device();