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refactor(vl53l1x): Extract magic values into named constants.
1 parent f72b549 commit 1bffc6d

2 files changed

Lines changed: 179 additions & 109 deletions

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‎lib/vl53l1x/vl53l1x/const.py‎

Lines changed: 38 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,38 @@
1+
from micropython import const
2+
3+
# I2C address
4+
VL53L1X_I2C_DEFAULT_ADDR = const(0x29)
5+
6+
# Device identification
7+
REG_MODEL_ID = const(0x010F)
8+
VL53L1X_DEVICE_ID = const(0xEACC)
9+
10+
# System control
11+
REG_SOFT_RESET = const(0x0000)
12+
SOFT_RESET_ASSERT = const(0x00)
13+
SOFT_RESET_RELEASE = const(0x01)
14+
15+
# Default configuration start register
16+
REG_DEFAULT_CONFIG_START = const(0x2D)
17+
18+
# Timing
19+
REG_RESULT_OSC_CALIBRATE_VAL = const(0x0022)
20+
REG_RANGE_CONFIG_VCSEL_PERIOD_A = const(0x001E)
21+
22+
# Ranging control
23+
REG_SYSTEM_START = const(0x0087)
24+
RANGING_START = const(0x40)
25+
RANGING_STOP = const(0x00)
26+
27+
# Interrupt
28+
REG_GPIO_HV_MUX_CTRL = const(0x0030)
29+
GPIO_HV_MUX_CTRL_POLARITY = const(0x10)
30+
REG_GPIO_TIO_HV_STATUS = const(0x0031)
31+
REG_SYSTEM_INTERRUPT_CLEAR = const(0x0086)
32+
INTERRUPT_CLEAR = const(0x01)
33+
34+
# Result registers
35+
REG_RESULT_RANGE_STATUS = const(0x0089)
36+
RESULT_BLOCK_SIZE = const(17)
37+
RESULT_DISTANCE_MSB_OFFSET = const(13)
38+
RESULT_DISTANCE_LSB_OFFSET = const(14)

‎lib/vl53l1x/vl53l1x/device.py‎

Lines changed: 141 additions & 109 deletions
Original file line numberDiff line numberDiff line change
@@ -1,114 +1,144 @@
11
import machine
22

3+
from vl53l1x.const import (
4+
GPIO_HV_MUX_CTRL_POLARITY,
5+
INTERRUPT_CLEAR,
6+
RANGING_START,
7+
RANGING_STOP,
8+
REG_DEFAULT_CONFIG_START,
9+
REG_GPIO_HV_MUX_CTRL,
10+
REG_GPIO_TIO_HV_STATUS,
11+
REG_MODEL_ID,
12+
REG_RANGE_CONFIG_VCSEL_PERIOD_A,
13+
REG_RESULT_OSC_CALIBRATE_VAL,
14+
REG_RESULT_RANGE_STATUS,
15+
REG_SOFT_RESET,
16+
REG_SYSTEM_INTERRUPT_CLEAR,
17+
REG_SYSTEM_START,
18+
RESULT_BLOCK_SIZE,
19+
RESULT_DISTANCE_LSB_OFFSET,
20+
RESULT_DISTANCE_MSB_OFFSET,
21+
SOFT_RESET_ASSERT,
22+
SOFT_RESET_RELEASE,
23+
VL53L1X_DEVICE_ID,
24+
VL53L1X_I2C_DEFAULT_ADDR,
25+
)
26+
327
VL53L1X_DEFAULT_CONFIGURATION = bytes(
428
[
5-
0x00, # 0x2d : fast plus mode disabled (set bit 2 and 5 to 1 for 1MHz I2C) */
6-
0x00, # 0x2e : bit 0 if I2C pulled up at 1.8V, else set bit 0 to 1 (pull up at AVDD) */
7-
0x00, # 0x2f : bit 0 if GPIO pulled up at 1.8V, else set bit 0 to 1 (pull up at AVDD) */
8-
0x01, # 0x30 : set bit 4 to 0 for active high interrupt and 1 for active low (bits 3:0 must be 0x1) */
9-
0x02, # 0x31 : bit 1 = interrupt depending on the polarity */
10-
0x00, # 0x32 : not user-modifiable */
11-
0x02, # 0x33 : not user-modifiable */
12-
0x08, # 0x34 : not user-modifiable */
13-
0x00, # 0x35 : not user-modifiable */
14-
0x08, # 0x36 : not user-modifiable */
15-
0x10, # 0x37 : not user-modifiable */
16-
0x01, # 0x38 : not user-modifiable */
17-
0x01, # 0x39 : not user-modifiable */
18-
0x00, # 0x3a : not user-modifiable */
19-
0x00, # 0x3b : not user-modifiable */
20-
0x00, # 0x3c : not user-modifiable */
21-
0x00, # 0x3d : not user-modifiable */
22-
0xFF, # 0x3e : not user-modifiable */
23-
0x00, # 0x3f : not user-modifiable */
24-
0x0F, # 0x40 : not user-modifiable */
25-
0x00, # 0x41 : not user-modifiable */
26-
0x00, # 0x42 : not user-modifiable */
27-
0x00, # 0x43 : not user-modifiable */
28-
0x00, # 0x44 : not user-modifiable */
29-
0x00, # 0x45 : not user-modifiable */
30-
0x20, # 0x46 : interrupt configuration 0x20 = new sample ready */
31-
0x0B, # 0x47 : not user-modifiable */
32-
0x00, # 0x48 : not user-modifiable */
33-
0x00, # 0x49 : not user-modifiable */
34-
0x02, # 0x4a : not user-modifiable */
35-
0x0A, # 0x4b : not user-modifiable */
36-
0x21, # 0x4c : not user-modifiable */
37-
0x00, # 0x4d : not user-modifiable */
38-
0x00, # 0x4e : not user-modifiable */
39-
0x05, # 0x4f : not user-modifiable */
40-
0x00, # 0x50 : not user-modifiable */
41-
0x00, # 0x51 : not user-modifiable */
42-
0x00, # 0x52 : not user-modifiable */
43-
0x00, # 0x53 : not user-modifiable */
44-
0xC8, # 0x54 : not user-modifiable */
45-
0x00, # 0x55 : not user-modifiable */
46-
0x00, # 0x56 : not user-modifiable */
47-
0x38, # 0x57 : not user-modifiable */
48-
0xFF, # 0x58 : not user-modifiable */
49-
0x01, # 0x59 : not user-modifiable */
50-
0x00, # 0x5a : not user-modifiable */
51-
0x08, # 0x5b : not user-modifiable */
52-
0x00, # 0x5c : not user-modifiable */
53-
0x00, # 0x5d : not user-modifiable */
54-
0x01, # 0x5e : not user-modifiable */
55-
0xDB, # 0x5f : not user-modifiable */
56-
0x0F, # 0x60 : not user-modifiable */
57-
0x01, # 0x61 : not user-modifiable */
58-
0xF1, # 0x62 : not user-modifiable */
59-
0x0D, # 0x63 : not user-modifiable */
60-
0x01, # 0x64 : Sigma threshold MSB (mm in 14.2 format for MSB+LSB), default value 90 mm */
61-
0x68, # 0x65 : Sigma threshold LSB */
62-
0x00, # 0x66 : Min count Rate MSB (MCPS in 9.7 format for MSB+LSB) */
63-
0x80, # 0x67 : Min count Rate LSB */
64-
0x08, # 0x68 : not user-modifiable */
65-
0xB8, # 0x69 : not user-modifiable */
66-
0x00, # 0x6a : not user-modifiable */
67-
0x00, # 0x6b : not user-modifiable */
68-
0x00, # 0x6c : Intermeasurement period MSB, 32 bits register */
69-
0x00, # 0x6d : Intermeasurement period */
70-
0x0F, # 0x6e : Intermeasurement period */
71-
0x89, # 0x6f : Intermeasurement period LSB */
72-
0x00, # 0x70 : not user-modifiable */
73-
0x00, # 0x71 : not user-modifiable */
74-
0x00, # 0x72 : distance threshold high MSB (in mm, MSB+LSB) */
75-
0x00, # 0x73 : distance threshold high LSB */
76-
0x00, # 0x74 : distance threshold low MSB (in mm, MSB+LSB) */
77-
0x00, # 0x75 : distance threshold low LSB */
78-
0x00, # 0x76 : not user-modifiable */
79-
0x01, # 0x77 : not user-modifiable */
80-
0x0F, # 0x78 : not user-modifiable */
81-
0x0D, # 0x79 : not user-modifiable */
82-
0x0E, # 0x7a : not user-modifiable */
83-
0x0E, # 0x7b : not user-modifiable */
84-
0x00, # 0x7c : not user-modifiable */
85-
0x00, # 0x7d : not user-modifiable */
86-
0x02, # 0x7e : not user-modifiable */
87-
0xC7, # 0x7f : ROI center */
88-
0xFF, # 0x80 : XY ROI (X=Width, Y=Height) */
89-
0x9B, # 0x81 : not user-modifiable */
90-
0x00, # 0x82 : not user-modifiable */
91-
0x00, # 0x83 : not user-modifiable */
92-
0x00, # 0x84 : not user-modifiable */
93-
0x01, # 0x85 : not user-modifiable */
94-
0x01, # 0x86 : clear interrupt */
95-
0x40, # 0x87 : start ranging, put 0x40 for automatic start after init */
29+
0x00, # 0x2d : fast plus mode disabled (set bit 2 and 5 to 1 for 1MHz I2C)
30+
0x00, # 0x2e : bit 0 if I2C pulled up at 1.8V, else set bit 0 to 1 (pull up at AVDD)
31+
0x00, # 0x2f : bit 0 if GPIO pulled up at 1.8V, else set bit 0 to 1 (pull up at AVDD)
32+
0x01, # 0x30 : set bit 4 to 0 for active high interrupt and 1 for active low (bits 3:0 must be 0x1)
33+
0x02, # 0x31 : bit 1 = interrupt depending on the polarity
34+
0x00, # 0x32 : not user-modifiable
35+
0x02, # 0x33 : not user-modifiable
36+
0x08, # 0x34 : not user-modifiable
37+
0x00, # 0x35 : not user-modifiable
38+
0x08, # 0x36 : not user-modifiable
39+
0x10, # 0x37 : not user-modifiable
40+
0x01, # 0x38 : not user-modifiable
41+
0x01, # 0x39 : not user-modifiable
42+
0x00, # 0x3a : not user-modifiable
43+
0x00, # 0x3b : not user-modifiable
44+
0x00, # 0x3c : not user-modifiable
45+
0x00, # 0x3d : not user-modifiable
46+
0xFF, # 0x3e : not user-modifiable
47+
0x00, # 0x3f : not user-modifiable
48+
0x0F, # 0x40 : not user-modifiable
49+
0x00, # 0x41 : not user-modifiable
50+
0x00, # 0x42 : not user-modifiable
51+
0x00, # 0x43 : not user-modifiable
52+
0x00, # 0x44 : not user-modifiable
53+
0x00, # 0x45 : not user-modifiable
54+
0x20, # 0x46 : interrupt configuration 0x20 = new sample ready
55+
0x0B, # 0x47 : not user-modifiable
56+
0x00, # 0x48 : not user-modifiable
57+
0x00, # 0x49 : not user-modifiable
58+
0x02, # 0x4a : not user-modifiable
59+
0x0A, # 0x4b : not user-modifiable
60+
0x21, # 0x4c : not user-modifiable
61+
0x00, # 0x4d : not user-modifiable
62+
0x00, # 0x4e : not user-modifiable
63+
0x05, # 0x4f : not user-modifiable
64+
0x00, # 0x50 : not user-modifiable
65+
0x00, # 0x51 : not user-modifiable
66+
0x00, # 0x52 : not user-modifiable
67+
0x00, # 0x53 : not user-modifiable
68+
0xC8, # 0x54 : not user-modifiable
69+
0x00, # 0x55 : not user-modifiable
70+
0x00, # 0x56 : not user-modifiable
71+
0x38, # 0x57 : not user-modifiable
72+
0xFF, # 0x58 : not user-modifiable
73+
0x01, # 0x59 : not user-modifiable
74+
0x00, # 0x5a : not user-modifiable
75+
0x08, # 0x5b : not user-modifiable
76+
0x00, # 0x5c : not user-modifiable
77+
0x00, # 0x5d : not user-modifiable
78+
0x01, # 0x5e : not user-modifiable
79+
0xDB, # 0x5f : not user-modifiable
80+
0x0F, # 0x60 : not user-modifiable
81+
0x01, # 0x61 : not user-modifiable
82+
0xF1, # 0x62 : not user-modifiable
83+
0x0D, # 0x63 : not user-modifiable
84+
0x01, # 0x64 : Sigma threshold MSB (mm in 14.2 format for MSB+LSB), default value 90 mm
85+
0x68, # 0x65 : Sigma threshold LSB
86+
0x00, # 0x66 : Min count Rate MSB (MCPS in 9.7 format for MSB+LSB)
87+
0x80, # 0x67 : Min count Rate LSB
88+
0x08, # 0x68 : not user-modifiable
89+
0xB8, # 0x69 : not user-modifiable
90+
0x00, # 0x6a : not user-modifiable
91+
0x00, # 0x6b : not user-modifiable
92+
0x00, # 0x6c : Intermeasurement period MSB, 32 bits register
93+
0x00, # 0x6d : Intermeasurement period
94+
0x0F, # 0x6e : Intermeasurement period
95+
0x89, # 0x6f : Intermeasurement period LSB
96+
0x00, # 0x70 : not user-modifiable
97+
0x00, # 0x71 : not user-modifiable
98+
0x00, # 0x72 : distance threshold high MSB (in mm, MSB+LSB)
99+
0x00, # 0x73 : distance threshold high LSB
100+
0x00, # 0x74 : distance threshold low MSB (in mm, MSB+LSB)
101+
0x00, # 0x75 : distance threshold low LSB
102+
0x00, # 0x76 : not user-modifiable
103+
0x01, # 0x77 : not user-modifiable
104+
0x0F, # 0x78 : not user-modifiable
105+
0x0D, # 0x79 : not user-modifiable
106+
0x0E, # 0x7a : not user-modifiable
107+
0x0E, # 0x7b : not user-modifiable
108+
0x00, # 0x7c : not user-modifiable
109+
0x00, # 0x7d : not user-modifiable
110+
0x02, # 0x7e : not user-modifiable
111+
0xC7, # 0x7f : ROI center
112+
0xFF, # 0x80 : XY ROI (X=Width, Y=Height)
113+
0x9B, # 0x81 : not user-modifiable
114+
0x00, # 0x82 : not user-modifiable
115+
0x00, # 0x83 : not user-modifiable
116+
0x00, # 0x84 : not user-modifiable
117+
0x01, # 0x85 : not user-modifiable
118+
0x01, # 0x86 : clear interrupt
119+
0x40, # 0x87 : start ranging, put 0x40 for automatic start after init
96120
]
97121
)
98122

99123

100124
class VL53L1X(object):
101-
def __init__(self, i2c, address=0x29):
125+
def __init__(self, i2c, address=VL53L1X_I2C_DEFAULT_ADDR):
102126
self.i2c = i2c
103127
self.address = address
104128
self.reset()
105129
machine.lightsleep(1)
106-
if self.device_id() != 0xEACC:
130+
if self.device_id() != VL53L1X_DEVICE_ID:
107131
raise RuntimeError("Failed to find expected ID register values. Check wiring!")
108-
# write default configuration
109-
self.i2c.writeto_mem(self.address, 0x2D, VL53L1X_DEFAULT_CONFIGURATION, addrsize=16)
110-
# adjust timing; assumes MM1 and MM2 are disabled
111-
self._write_reg16(0x001E, self._read_reg16(0x0022) * 4)
132+
# Write default configuration
133+
self.i2c.writeto_mem(
134+
self.address, REG_DEFAULT_CONFIG_START,
135+
VL53L1X_DEFAULT_CONFIGURATION, addrsize=16,
136+
)
137+
# Adjust timing; assumes MM1 and MM2 are disabled
138+
self._write_reg16(
139+
REG_RANGE_CONFIG_VCSEL_PERIOD_A,
140+
self._read_reg16(REG_RESULT_OSC_CALIBRATE_VAL) * 4,
141+
)
112142
machine.lightsleep(200)
113143

114144
def _write_reg(self, reg, value):
@@ -127,33 +157,33 @@ def _read_reg16(self, reg):
127157
return (data[0] << 8) + data[1]
128158

129159
def device_id(self):
130-
return self._read_reg16(0x010F)
160+
return self._read_reg16(REG_MODEL_ID)
131161

132162
def reset(self):
133-
self._write_reg(0x0000, 0x00)
163+
self._write_reg(REG_SOFT_RESET, SOFT_RESET_ASSERT)
134164
machine.lightsleep(100)
135-
self._write_reg(0x0000, 0x01)
165+
self._write_reg(REG_SOFT_RESET, SOFT_RESET_RELEASE)
136166

137167
def power_off(self):
138-
self._write_reg(0x0000, 0x00)
168+
self._write_reg(REG_SOFT_RESET, SOFT_RESET_ASSERT)
139169

140170
def power_on(self):
141-
self._write_reg(0x0000, 0x01)
171+
self._write_reg(REG_SOFT_RESET, SOFT_RESET_RELEASE)
142172
machine.lightsleep(1)
143173

144174
def start_ranging(self):
145-
self._write_reg(0x0087, 0x40)
175+
self._write_reg(REG_SYSTEM_START, RANGING_START)
146176

147177
def stop_ranging(self):
148-
self._write_reg(0x0087, 0x00)
178+
self._write_reg(REG_SYSTEM_START, RANGING_STOP)
149179

150180
def data_ready(self):
151-
polarity = self._read_reg(0x0030) & 0x10
181+
polarity = self._read_reg(REG_GPIO_HV_MUX_CTRL) & GPIO_HV_MUX_CTRL_POLARITY
152182
ready_val = 1 if polarity == 0 else 0
153-
return (self._read_reg(0x0031) & 0x01) == ready_val
183+
return (self._read_reg(REG_GPIO_TIO_HV_STATUS) & 0x01) == ready_val
154184

155185
def _clear_interrupt(self):
156-
self._write_reg(0x0086, 0x01)
186+
self._write_reg(REG_SYSTEM_INTERRUPT_CLEAR, INTERRUPT_CLEAR)
157187

158188
def _ensure_data(self):
159189
if not self.data_ready():
@@ -166,8 +196,10 @@ def _ensure_data(self):
166196

167197
def distance_mm(self):
168198
self._ensure_data()
169-
data = self.i2c.readfrom_mem(self.address, 0x0089, 17, addrsize=16)
170-
distance_mm = (data[13] << 8) + data[14]
199+
data = self.i2c.readfrom_mem(
200+
self.address, REG_RESULT_RANGE_STATUS, RESULT_BLOCK_SIZE, addrsize=16,
201+
)
202+
distance_mm = (data[RESULT_DISTANCE_MSB_OFFSET] << 8) + data[RESULT_DISTANCE_LSB_OFFSET]
171203
self._clear_interrupt()
172204
return distance_mm
173205

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