Tlakoměr

Dalším zajímavým senzorem je tlakoměr LPS25HB. Z předchozího příspěvku už víme, jaká je jeho adresa a můžeme si rovnou vyčíst obsah paměti root@AR150:~# i2cdump -y 0 0x5d.

	0	1	2	3	4	5	6	7	8	9	a	b	c	d	e	f	0123456789abcdef
00:	00	00	00	00	00	00	00	00	00	00	00	00	00	00	c0	bd	..............??
10:	0f	1b	00	00	08	e6	9e	12	b1	6f	60	00	66	26	58	4a	??..?????o`.f&XJ
20:	00	00	00	00	00	00	00	00	00	80	2f	00	00	00	00	20	.........?/....
30:	00	00	f5	81	fb	26	15	4f	40	00	00	00	00	00	c0	01	..???&?O@.....??
40:	00	00	00	00	00	00	00	00	00	00	00	00	00	00	00	00	................
50:	00	00	00	00	00	00	00	00	00	00	00	00	00	00	00	00	................
60:	00	00	00	00	00	00	00	00	00	00	00	00	00	00	00	00	................
70:	00	00	00	00	00	00	00	00	00	00	00	00	00	00	00	00	................
80:	00	00	00	00	00	00	00	00	00	00	00	00	00	00	c0	bd	..............??
90:	0f	1b	00	00	08	e6	9e	12	b1	6f	60	00	66	26	58	4a	??..?????o`.f&XJ
a0:	00	00	00	00	00	00	00	00	00	80	2f	00	00	00	00	20	.........?/....
b0:	00	00	f5	81	fb	26	15	4f	40	00	00	00	00	00	c0	01	..???&?O@.....??
c0:	00	00	00	00	00	00	00	00	00	00	00	00	00	00	00	00	................
d0:	00	00	00	00	00	00	00	00	00	00	00	00	00	00	00	00	................
e0:	00	00	00	00	00	00	00	00	00	00	00	00	00	00	00	00	................
f0:	00	00	00	00	00	00	00	00	00	00	00	00	00	00	00	00	................

WHO_I_AM         0xbd

bc

PRESSURE          0xF6C7

c7

f6

TEMP                    0x0112

12

01

Zde je reference tříbajtové znaménkové číslo (0x0A představuje MSB a 0x08 obsahuje LSB), po inicializaci je hodnota těchto registrů nulová, nahození bitu AUTOZERO dojde k změření aktuálního tlaku a tento je použit jako referenční tlak.

http://www.st.com/web/en/resource/technical/document/datasheet/DM00141379.pdf