sys/phydat: Fix unit confusion

Previously, `UNIT_G` was used for g-force with the correct symbol `g`,
`UNIT_GR` for gram (as in kilogram) with the incorrect symbol `G` (which
would be correct for Gauss), and `UNIT_GS` for Gauss with symbol `Gs`
(which is an uncommon but correct symbol).

To avoid confusion between G-Force, Gauss, and Gram the units have been
renamed to `UNIT_G_FORCE`, `UNIT_GRAM`, and `UNIT_GAUSS`. In addition,
gram now uses the correct symbol `g` and Gauss uses `G`.

drivers/adxl345/adxl345_saul.c

@@ -25,7 +25,7 @@ static int read_acc(const void *dev, phydat_t *res)
 {
     adxl345_read((const adxl345_t *)dev, (adxl345_data_t *)res->val);
 
-    res->unit = UNIT_G;
+    res->unit = UNIT_G_FORCE;
     res->scale = -3;
     return 3;
 }

drivers/bmx055/bmx055_saul.c

@@ -29,7 +29,7 @@ static int read_mag(const void *dev, phydat_t *res)
     if (bmx055_mag_read(mydev, res->val) != BMX055_OK) {
         return 0;
     }
-    res->unit = UNIT_GS;
+    res->unit = UNIT_GAUSS;
     res->scale = 0;
     return 3;
 }
@@ -41,7 +41,7 @@ static int read_acc(const void *dev, phydat_t *res)
     if (bmx055_acc_read(mydev, res->val) != BMX055_OK) {
         return 0;
     }
-    res->unit = UNIT_G;
+    res->unit = UNIT_G_FORCE;
     res->scale = -3;
     return 3;
 }

drivers/fxos8700/fxos8700_saul.c

@@ -31,7 +31,7 @@ static int read_mag(const void *dev, phydat_t *res)
         /* Read failure */
         return -ECANCELED;
     }
-    res->unit = UNIT_GS;
+    res->unit = UNIT_GAUSS;
     res->scale = -3;
     return 3;
 }
@@ -48,7 +48,7 @@ static int read_acc(const void *dev, phydat_t *res)
         res->scale = 0;
     }
     else {
-        res->unit = UNIT_G;
+        res->unit = UNIT_G_FORCE;
         if (((fxos8700_t *)dev)->p.acc_range == FXOS8700_REG_XYZ_DATA_CFG_FS__2G) {
             res->scale = -4;
         }

drivers/hmc5883l/hmc5883l_saul.c

@@ -28,7 +28,7 @@ static int read(const void *dev, phydat_t *res)
     res->val[0] = data.x;
     res->val[1] = data.y;
     res->val[2] = data.z;
-    res->unit = UNIT_GS;
+    res->unit = UNIT_GAUSS;
     res->scale = -3;
     return 3;
 }

drivers/lis2dh12/lis2dh12_saul.c

@@ -26,7 +26,7 @@ static int read_accelerometer(const void *dev, phydat_t *res)
     if (lis2dh12_read(dev, (lis2dh12_fifo_data_t*)res->val) != LIS2DH12_OK) {
         return 0;
     }
-    res->unit = UNIT_G;
+    res->unit = UNIT_G_FORCE;
     res->scale = -3;
     return 3;
 }

drivers/lis3dh/lis3dh_saul.c

@@ -39,7 +39,7 @@ static int read_acc(const void *dev, phydat_t *res)
     res->val[2] = xyz.acc_z;
     /* unit: milli-G */
     res->scale = -3;
-    res->unit = UNIT_G;
+    res->unit = UNIT_G_FORCE;
 
     return 3;
 }

drivers/lis3mdl/lis3mdl_saul.c

@@ -29,7 +29,7 @@ static int read_mag(const void *dev, phydat_t *res)
 
     lis3mdl_read_mag(d, (lis3mdl_3d_data_t *)res);
 
-    res->unit = UNIT_GS;
+    res->unit = UNIT_GAUSS;
     res->scale = -3;
     return 3;
 }

drivers/lsm303dlhc/lsm303dlhc_saul.c

@@ -34,7 +34,7 @@ static int read_acc(const void *dev, phydat_t *res)
         res->val[i] *= fac;
     }
 
-    res->unit = UNIT_G;
+    res->unit = UNIT_G_FORCE;
     res->scale = -3;
     return 3;
 }
@@ -63,7 +63,7 @@ static int read_mag(const void *dev, phydat_t *res)
         res->val[i] = (int16_t)tmp;
     }
 
-    res->unit = UNIT_GS;
+    res->unit = UNIT_GAUSS;
     res->scale = -3;
     return 3;
 }

drivers/lsm6dsl/lsm6dsl_saul.c

@@ -31,7 +31,7 @@ static int read_acc(const void *dev, phydat_t *res)
     }
 
     res->scale = -3;
-    res->unit = UNIT_G;
+    res->unit = UNIT_G_FORCE;
 
     return 3;
 }

drivers/mag3110/mag3110_saul.c

@@ -28,7 +28,7 @@ static int read_mag(const void *dev, phydat_t *res)
 {
     mag3110_read((const mag3110_t *)dev, (mag3110_data_t *)res->val);
 
-    res->unit = UNIT_GS;
+    res->unit = UNIT_GAUSS;
     res->scale = 2;
 
     return 3;

drivers/mma7660/mma7660_saul.c

@@ -28,7 +28,7 @@ static int read_acc(const void *dev, phydat_t *res)
 {
     mma7660_read((const mma7660_t *)dev, (mma7660_data_t *)res->val);
 
-    res->unit = UNIT_G;
+    res->unit = UNIT_G_FORCE;
     res->scale = -3;
 
     return 3;

drivers/mma8x5x/mma8x5x_saul.c

@@ -29,7 +29,7 @@ static int read_acc(const void *dev, phydat_t *res)
 {
     mma8x5x_read((const mma8x5x_t *)dev, (mma8x5x_data_t *)res->val);
 
-    res->unit = UNIT_G;
+    res->unit = UNIT_G_FORCE;
     res->scale = -3;
 
     return 3;

drivers/mpu9x50/mpu9x50_saul.c

@@ -33,7 +33,7 @@ static int read_acc(const void *dev, phydat_t *res)
     }
 
     res->scale = -3;
-    res->unit = UNIT_G;
+    res->unit = UNIT_G_FORCE;
 
     return 3;
 }
@@ -59,7 +59,7 @@ static int read_mag(const void *dev, phydat_t *res)
     }
 
     res->scale = -2;
-    res->unit = UNIT_GS;
+    res->unit = UNIT_GAUSS;
 
     return 3;
 }

drivers/qmc5883l/qmc5883l_saul.c

@@ -27,7 +27,7 @@ static int read(const void *dev, phydat_t *res)
 {
     int ret = qmc5883l_read((const qmc5883l_t *)dev, res->val);
     if ((ret == QMC5883L_OK) || (ret == QMC5883L_OVERFLOW)) {
-        res->unit = UNIT_GS;
+        res->unit = UNIT_GAUSS;
         res->scale = -3;
         return 3;
     }

sys/include/phydat.h

@@ -87,16 +87,19 @@ enum {
     UNIT_M2,        /**< square meters */
     UNIT_M3,        /**< cubic meters */
     /* kinetic */
-    UNIT_G,         /**< gravitational force */
+    UNIT_G_FORCE,   /**< gravitational force equivalent */
+    UNIT_G = UNIT_G_FORCE, /**< @deprecated, use UNIT_G_FORCE instead */
     UNIT_DPS,       /**< degree per second */
     /* weight */
-    UNIT_GR,        /**< grams - not using the SI unit (kg) here to make scale
+    UNIT_GRAM,      /**< grams - not using the SI unit (kg) here to make scale
                      *   handling simpler */
+    UNIT_GR = UNIT_GRAM, /**< @deprecated, use UNIT_GRAM instead */
     /* electricity */
     UNIT_A,         /**< Ampere */
     UNIT_V,         /**< Volts */
     UNIT_W,         /**< Watt */
-    UNIT_GS,        /**< gauss */
+    UNIT_GAUSS,     /**< gauss */
+    UNIT_GS = UNIT_GAUSS, /**< @deprecated, use UNIT_GAUSS instead */
     UNIT_T,         /**< Tesla */
     UNIT_DBM,       /**< decibel-milliwatts */
     UNIT_COULOMB,   /**< coulomb */

sys/include/senml/phydat.h

@@ -58,10 +58,10 @@ void phydat_to_senml_bool(senml_bool_value_t *senml, const phydat_t *phydat, con
  *
  * - @ref UNIT_TIME is converted to @ref SENML_UNIT_SECOND.
  * - @ref UNIT_F is converted to @ref SENML_UNIT_KELVIN.
- * - @ref UNIT_G is converted to @ref SENML_UNIT_METER_PER_SQUARE_SECOND.
+ * - @ref UNIT_G_FORCE is converted to @ref SENML_UNIT_METER_PER_SQUARE_SECOND.
  * - @ref UNIT_BAR is converted to @ref SENML_UNIT_PASCAL.
  * - @ref UNIT_GPM3 is converted to @ref SENML_UNIT_KILOGRAM_PER_CUBIC_METER.
- * - @ref UNIT_GS is converted to @ref SENML_UNIT_TESLA.
+ * - @ref UNIT_GAUSS is converted to @ref SENML_UNIT_TESLA.
  * - Compatible units are set to their SenML equivalent.
  * - Incompatible (or unknown) units are set to @ref SENML_UNIT_NONE.
  *
@@ -80,7 +80,7 @@ void phydat_to_senml_float(senml_value_t *senml, const phydat_t *phydat, const u
  * - @ref UNIT_TIME is converted to @ref SENML_UNIT_SECOND.
  * - @ref UNIT_BAR is converted to @ref SENML_UNIT_PASCAL.
  * - @ref UNIT_GPM3 is converted to @ref SENML_UNIT_KILOGRAM_PER_CUBIC_METER.
- * - @ref UNIT_GS is converted to @ref SENML_UNIT_TESLA.
+ * - @ref UNIT_GAUSS is converted to @ref SENML_UNIT_TESLA.
  * - Compatible units are set to their SenML equivalent.
  * - Incompatible (or unknown) units are set to @ref SENML_UNIT_NONE.
  *

sys/phydat/phydat_str.c

@@ -106,14 +106,14 @@ const char *phydat_unit_to_str(uint8_t unit)
         case UNIT_M:        return "m";
         case UNIT_M2:       return "m^2";
         case UNIT_M3:       return "m^3";
-        case UNIT_G:        return "g";
+        case UNIT_G_FORCE:  return "gₙ";
         case UNIT_DPS:      return "dps";
-        case UNIT_GR:       return "G";
+        case UNIT_GRAM:     return "g";
         case UNIT_A:        return "A";
         case UNIT_V:        return "V";
         case UNIT_W:        return "W";
         case UNIT_DBM:      return "dBm";
-        case UNIT_GS:       return "Gs";
+        case UNIT_GAUSS:    return "Gs";
         case UNIT_T:        return "T";
         case UNIT_BAR:      return "Bar";
         case UNIT_PA:       return "Pa";

sys/senml/phydat.c

@@ -24,7 +24,7 @@ static uint8_t phydat_unit_to_senml_unit(uint8_t unit)
     case UNIT_M:       return SENML_UNIT_METER;
     case UNIT_M2:      return SENML_UNIT_SQUARE_METER;
     case UNIT_M3:      return SENML_UNIT_CUBIC_METER;
-    case UNIT_GR:      return SENML_UNIT_GRAM;
+    case UNIT_GRAM:    return SENML_UNIT_GRAM;
     case UNIT_A:       return SENML_UNIT_AMPERE;
     case UNIT_V:       return SENML_UNIT_VOLT;
     case UNIT_W:       return SENML_UNIT_WATT;
@@ -45,8 +45,8 @@ static uint8_t phydat_unit_to_senml_unit(uint8_t unit)
 
     /* Incompatible units */
     case UNIT_TEMP_F:  return SENML_UNIT_NONE;      /* use K or Cel instead */
-    case UNIT_GS:      return SENML_UNIT_NONE;      /* use T instead */
+    case UNIT_GAUSS:   return SENML_UNIT_NONE;      /* use T instead */
-    case UNIT_G:       return SENML_UNIT_NONE;      /* use m/s2 instead */
+    case UNIT_G_FORCE: return SENML_UNIT_NONE;      /* use m/s2 instead */
     case UNIT_BAR:     return SENML_UNIT_NONE;      /* use Pa or hPa instead */
     case UNIT_TIME:    return SENML_UNIT_NONE;      /* split into second/minute/hour */
     case UNIT_DATE:    return SENML_UNIT_NONE;      /* split into day/month/year */
@@ -87,7 +87,7 @@ void phydat_to_senml_float(senml_value_t *senml, const phydat_t *phydat, const u
         value = (value + 459.67) * (5. / 9.);
         senml->attr.unit = SENML_UNIT_KELVIN;
         break;
-    case UNIT_G:
+    case UNIT_G_FORCE:
         /* convert gravitational acceleration to acceleration */
         value *= 9.80665;
         senml->attr.unit = SENML_UNIT_METER_PER_SQUARE_SECOND;
@@ -100,7 +100,7 @@ void phydat_to_senml_float(senml_value_t *senml, const phydat_t *phydat, const u
         value *= 0.001;
         senml->attr.unit = SENML_UNIT_KILOGRAM_PER_CUBIC_METER;
         break;
-    case UNIT_GS:
+    case UNIT_GAUSS:
         value *= 0.0001;
         senml->attr.unit = SENML_UNIT_TESLA;
         break;
@@ -138,7 +138,7 @@ void phydat_to_senml_decimal(senml_value_t *senml, const phydat_t *phydat, const
         e -= 3;
         senml->attr.unit = SENML_UNIT_KILOGRAM_PER_CUBIC_METER;
         break;
-    case UNIT_GS:
+    case UNIT_GAUSS:
         e -= 4;
         senml->attr.unit = SENML_UNIT_TESLA;
         break;

tests/phydat_dump/main.c

@@ -39,13 +39,13 @@ _phydat_test_t _test_vector[] =
     { .dim = 3, .dat = { .val = { 1234, 13456, -14567 }, .unit = UNIT_M, .scale = -3 } },
     { .dim = 1, .dat = { .val = { -12345 }, .unit = UNIT_M2, .scale = -5 } },
     { .dim = 1, .dat = { .val = { -12345 }, .unit = UNIT_M3, .scale = -6 } },
-    { .dim = 3, .dat = { .val = { 12, 34, 5678}, .unit = UNIT_G, .scale = -2 } },
+    { .dim = 3, .dat = { .val = { 12, 34, 5678}, .unit = UNIT_G_FORCE, .scale = -2 } },
     { .dim = 3, .dat = { .val = { 123, 345, 678 }, .unit = UNIT_DPS, .scale = -3 } },
-    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_GR, .scale = -1 } },
+    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_GRAM, .scale = -1 } },
     { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_A, .scale = 3 } },
     { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_V, .scale = 6 } },
     { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_W, .scale = 7 } },
-    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_GS, .scale = -1 } },
+    { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_GAUSS, .scale = -1 } },
     { .dim = 3, .dat = { .val = { 123, 456, 789 }, .unit = UNIT_T, .scale = -9 } },
     { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_DBM, .scale = -3 } },
     { .dim = 1, .dat = { .val = { 12345 }, .unit = UNIT_COULOMB, .scale = 0 } },

tests/phydat_dump/tests/01-run.py

@@ -33,13 +33,13 @@ def testfunc(child):
     child.expect(r'\t\[2\]      -14567 mm\r\n')
     child.expect(r'Data:\t       -0.12345 m\^2\r\n')
     child.expect(r'Data:\t      -12345e-6 m\^3\r\n')
-    child.expect(r'Data:\t\[0\]        0.12 g\r\n')
+    child.expect(r'Data:\t\[0\]        0.12 gₙ\r\n')
-    child.expect(r'\t\[1\]        0.34 g\r\n')
+    child.expect(r'\t\[1\]        0.34 gₙ\r\n')
-    child.expect(r'\t\[2\]       56.78 g\r\n')
+    child.expect(r'\t\[2\]       56.78 gₙ\r\n')
     child.expect(r'Data:\t\[0\]         123 mdps\r\n')
     child.expect(r'\t\[1\]         345 mdps\r\n')
     child.expect(r'\t\[2\]         678 mdps\r\n')
-    child.expect(r'Data:\t         1234.5 G\r\n')
+    child.expect(r'Data:\t         1234.5 g\r\n')
     child.expect(r'Data:\t          12345 kA\r\n')
     child.expect(r'Data:\t          12345 MV\r\n')
     child.expect(r'Data:\t        12345e7 W\r\n')

tests/senml_phydat/main.c

@@ -84,7 +84,7 @@ static value_test_t value_tests[] = {
         .senml2 = senml_df(0, 3, SENML_UNIT_NONE),
     },
     {
-        .phydat = { { 314, 0, 0 }, UNIT_G, -2 },
+        .phydat = { { 314, 0, 0 }, UNIT_G_FORCE, -2 },
         .senml1 = senml_f(30.792881, SENML_UNIT_METER_PER_SQUARE_SECOND),
         .senml2 = senml_df(314, -2, SENML_UNIT_NONE),
     },
@@ -99,7 +99,7 @@ static value_test_t value_tests[] = {
         .senml2 = senml_df(193, 2, SENML_UNIT_KILOGRAM_PER_CUBIC_METER),
     },
     {
-        .phydat = { { 220, 0, 0 }, UNIT_GS, 3 },
+        .phydat = { { 220, 0, 0 }, UNIT_GAUSS, 3 },
         .senml1 = senml_f(22, SENML_UNIT_TESLA),
         .senml2 = senml_df(220, -1, SENML_UNIT_TESLA),
     }

tests/unittests/tests-phydat/tests-phydat.c

@@ -58,8 +58,8 @@ static tdat_t data[] = {
     },
     {
         .dim  = 3,
-        .dat  = { { 1032, 10, -509 }, UNIT_G, -3 },
+        .dat  = { { 1032, 10, -509 }, UNIT_G_FORCE, -3 },
-        .json = "{\"d\":[1.032,0.010,-0.509],\"u\":\"g\"}",
+        .json = "{\"d\":[1.032,0.010,-0.509],\"u\":\"gₙ\"}",
     },
     {
         .dim  = 3,
@@ -204,14 +204,14 @@ static void test_unitstr__success(void)
     TEST_ASSERT_EQUAL_STRING("m", phydat_unit_to_str_verbose(UNIT_M));
     TEST_ASSERT_EQUAL_STRING("m^2", phydat_unit_to_str_verbose(UNIT_M2));
     TEST_ASSERT_EQUAL_STRING("m^3", phydat_unit_to_str_verbose(UNIT_M3));
-    TEST_ASSERT_EQUAL_STRING("g", phydat_unit_to_str_verbose(UNIT_G));
+    TEST_ASSERT_EQUAL_STRING("gₙ", phydat_unit_to_str_verbose(UNIT_G_FORCE));
     TEST_ASSERT_EQUAL_STRING("dps", phydat_unit_to_str_verbose(UNIT_DPS));
-    TEST_ASSERT_EQUAL_STRING("G", phydat_unit_to_str_verbose(UNIT_GR));
+    TEST_ASSERT_EQUAL_STRING("g", phydat_unit_to_str_verbose(UNIT_GRAM));
     TEST_ASSERT_EQUAL_STRING("A", phydat_unit_to_str_verbose(UNIT_A));
     TEST_ASSERT_EQUAL_STRING("V", phydat_unit_to_str_verbose(UNIT_V));
     TEST_ASSERT_EQUAL_STRING("W", phydat_unit_to_str_verbose(UNIT_W));
     TEST_ASSERT_EQUAL_STRING("dBm", phydat_unit_to_str_verbose(UNIT_DBM));
-    TEST_ASSERT_EQUAL_STRING("Gs", phydat_unit_to_str_verbose(UNIT_GS));
+    TEST_ASSERT_EQUAL_STRING("Gs", phydat_unit_to_str_verbose(UNIT_GAUSS));
     TEST_ASSERT_EQUAL_STRING("T", phydat_unit_to_str_verbose(UNIT_T));
     TEST_ASSERT_EQUAL_STRING("Bar", phydat_unit_to_str_verbose(UNIT_BAR));
     TEST_ASSERT_EQUAL_STRING("Pa", phydat_unit_to_str_verbose(UNIT_PA));