-
Notifications
You must be signed in to change notification settings - Fork 4
/
ActivityBoardAdc.spin
123 lines (89 loc) · 4.84 KB
/
ActivityBoardAdc.spin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
CON
{{
Modified by Duane Degn
The software is a modified version of Jon McPalen's "jm_adc124s021.spin" object.
The modifications are intended to make it easier to use part of the "Eddie"
robot's firmware.
The Propeller Activity board uses an ADC124S021 analog to digital converter chip. This is
a 4 channel 12-bit device. To make the Activity Board version of the Eddie firmware
backwards compatible, the readings of the four channels will be availble from two
different channel IDs. For example, the first channel's reading will be available when
requested from both channel 0 and channel 4.
These modifications were made as part of Parallax's Open Propeller Project #8.
For more information about this project see the following thread on the Parallax forums:
http://forums.parallax.com/showthread.php/158030
Some of the changes I made include changing the name of the "start" method to "init"
to comply with the convention of only using "start" with methods which start a new
cog. The "read" method was modified to accept the channel number or the channel
number plus four.
The formatting was changed to more closely agree with the Parallax Gold Standard
formatting conventions.
Header to the original object below.
}}
'' ==========================================================================================
''
'' File....... jm_adc124s021.spin
'' Purpose.... Interface for ADC124S021 ADC chip (used on Propeller Activity Board)
'' Author..... Jon "JonnyMac" McPhalen
'' Copyright (c) 2013-14 Jon McPhalen
'' -- see below for terms of use
'' E-mail..... jon@jonmcphalen.com
'' Started....
'' Updated.... 09 OCT 2014
''
'' ==========================================================================================
{{
Note on object: The ADC returns the channel value set in the _previous_ read cycle, hence
this code uses a double read each time to ensure the current channel value is returned.
}}
VAR
long cs ' active-low chip select
long sck ' active-low clock
long mosi ' prop -> adc.di
long miso ' prop <- adc.do
PUB Init(cspin, sckpin, dipin, dopin)
'' Configure IO pins used by ADC
'' -- pins define connections to ADC124S021
longmove(@cs, @cspin, 4) ' copy pins
outa[cs] := 1 ' output high to disable
dira[cs] := 1
outa[sck] := 1 ' output high
dira[sck] := 1
dira[miso] := 0 ' input (from adc)
dira[mosi] := 1 ' output (to adc)
PUB Read(ch) | ctrlbits, adcval
'' Reads adc (ADC124S021) channel, 0 - 3 (with ID's 0 - 7)
'' -- returns 12-bit value
'' The channel may be read by identifing the channel number
'' or the channel number plus four.
if ((ch < 0) or (ch > 7)) ' validate channel
return -1
if ch > 3
ch -= 4
ctrlbits := ((ch << 3) << 24) | ((ch << 3) << 8) ' config for two reads
outa[cs] := 0 ' select device
repeat 32 ' two complete reads
outa[sck] := 0 ' clock low
outa[mosi] := (ctrlbits <-= 1) ' output control bits
adcval := (adcval << 1) | ina[miso] ' get result bit
outa[sck] := 1 ' clock high
outa[cs] := 1 ' deselect device
return adcval & $0FFF ' return 2nd read
DAT { license }
{{
Terms of Use: MIT License
Permission is hereby granted, free of charge, to any person obtaining a copy of this
software and associated documentation files (the "Software"), to deal in the Software
without restriction, including without limitation the rights to use, copy, modify,
merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to miso so, subject to the following
conditions:
The above copyright notice and this permission notice shall be included in all copies
or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
}}