Project

General

Profile

Assembling the LAOS electronics boards » History » Version 9

darrenp, 2012-11-25 02:33

1 2 jaap
{{>toc}}
2
3 1 jaap
h1. Assembling the LAOS electronics boards
4
5
h2. Board version, layout and schematics
6
7
!Laos_rev3.png!
8
9
Before you start, make sure you know which version of the board you have! This page describes Rev3 of the board. Older versions have some bugs that need to be fixed before you start soldering the parts on:
10 5 KalleP
* *Rev 0.1* has no LOGO, it has some very visible bugs. One of the is that the LED connectors have no pre-tinned pads on both sides of the board, but only on the top side. If you see that, you most definitly have Rev 1. See [[Mainboard_Rev1]]
11
* *Rev 0.2* has a LaosLaser LOGO under the SD. See [[Mainboard_Rev2]]
12 1 jaap
* *Rev 0.3* has no LOGO, but it says LAOS Board v0.3 just above the MBED.
13 5 KalleP
* *Rev 0.4* has LaosLaser LOGO under MBED and reads LAOS Board rev4 on USB side of MBED.
14 1 jaap
15 7 hugomeiland
!>IMG_1067.JPG!
16
17 5 KalleP
The older boards have small bugs, but none of them is bad enough to replace your old board with a newer one. The bugs can be fixed with simple soldering solutions, making the boards just as good as Rev 0.3. The Rev 0.4 is also a minor bug fix with extra filter capacitors under the Pololu stepper drivers is an improvement.
18 1 jaap
19
Before you start soldering:
20
* read the [[LAOS_Mainboard_v03]] page and make sure you have the parts you need
21 4 peter
* download layout and schematics PDF's from the bottom of that page, and print them out, or have them available for reference on your PC monitor.
22
This simplifies searching for component location and component values.
23 1 jaap
24
25
h2. Soldering the board
26
27
h3. SD card socket
28
29 5 KalleP
Solder the SD card socket in place first on the component (top) side, as it is the only SMD component and it's nice to have some space around it when soldering. Remember to solder the shield pads from the bottom
30 1 jaap
31
h3. DIL Sockets
32
33 5 KalleP
Place the two DIL sockets the opto-couplers (OPTO-IN, OPTO-OUT) and the one for the CANBUS chip (optional) and solder them in place, keeping the index notch on the same end as indicated on the board.
34 1 jaap
35
h3. MBED footprint
36
37
Solder two rows of pin receptacles in place for the MBED. The outer rows are optional (debugging or expansion only).
38
39
h3. Pololu only
40
41
If you want to use Pololu stepper drivers or the compatible [http://reprap.org/wiki/StepStick StepStick] drivers:
42
43
Solder in the two rows of pin header sockets for each Pololu.
44
* J8: Z-Axis
45
* J17: Y-Axis
46
* J23: X-Axis
47
* J32: Extra (Extruder, Rotation) Axis (probably you can skip this one for a laser)
48
49 9 darrenp
!Pololu-jumpers.jpg! 
50 1 jaap
51 5 KalleP
On the solder (bottom) side of the board, there are 4 groups of 3x2 solder pads next to the Pololu headers. With these solder pads you can configure microstepping on the Pololu's. If you connect all of them, you get the maximum number of microsteps. '''Note:''' do not connect the (90 degree rotated sets of) solder pads '''inside''' (3 of the 4) the Pololu footprints. These pass through jumpers should be connected '''only''' if you are using externals stepper drivers, instead of Pololu's, at which point the Pololu configuration jumpers are ignored.
52 1 jaap
53 8 darrenp
For Microstepping with Pololu, the following settings are available (Low = Not Connected, High = Connected) :
54
55
|MS1|MS2|MS3|Resolution|
56
|Low|Low|Low|Full Step|
57
|High|Low|Low|Half Step|
58
|Low|High|Low|Quarter Step|
59
|High|High|Low|Eighth Step|
60
|High|High|High|Sixteenth Step|
61
62
MS1 is closest to the Pololu, MS3 is closest to the MBed
63
64
65 1 jaap
h3. Non-Pololu only
66
67
If you're not using Pololu-compatible stepper drivers on the mainboard but some other ''external'' stepper driver boards:
68 5 KalleP
* Connect the solder pads on the bottom of the board (under the Pololu footprints) two by two
69 1 jaap
!Pololu_solderpads.jpg!
70
71
Depending on your stepper drivers, you will need:
72
* GND: this can be enabled on the outgoing connectors by filling the solder pad under the connector.
73
* Some voltage: you can use Vmot by filling the solder pad under the connector (the square pole is +). If you need 3V3 you can make a wire between the pololu pins (10) and (14). If you need 5V, you can make a wire from a 5V net to pololu pin (14). 
74
75
If you need all five pins, the standard Phoenix connectors will not fit, so you will have to get Phoenix mini or other connectors (e.54mm pitch).
76
77
h3. Resistors
78
79
Find the resistors and put them in the print.
80
|_.Value|_.Count|_.Resistor numbers|
81
|100 Ohm|1|R34|
82
|120 Ohm|1|R1|
83
|330 Ohm|4|R28, R29, R31, R32|
84
|1K|15|R2, R3, R6, R11, R12, R14, R15, R17, R22, R23, R24, R26, R27, R30, R33|
85
|2K2|2|R7, R8|
86
|10K|11|R4, R5, R9, R10, R13, R16, R18, R19, R20, R21, R25|
87
88
Bear in mind that R8 (which sits underneath R7 may have a trace crossing it so it may appear like R6), make sure that this is not the case, the real R6 is part of the R4, R9 and R6 row).
89
90
You can solder in all resistors, or omit the ones you don't need. We advise to leave out resistor R10 and R12 for now, because these can do BAD THINGS (tm) to your MBED if you choose the wrong value. Their correct values are handled in a later chapter.
91
92
h4. Resistor list
93
94
|_.Number|_.Value (Ohm)|_.Function|_.Common|_.Optional|
95
|R1|120|Can Bus|  |Only needed for Can Bus|
96
|R2|1K|Magjack LED|X|Only needed for Magjack with LEDs|
97 5 KalleP
|R3|1K|Magjack LED| |Can be omitted, only needed when Magjack has LEDs!|
98 1 jaap
|R4|10K|Enable LED|X|If you do not want LEDs on your board, this resistor is not needed|
99
|R5|10K|VMOT LED|X|If you do not want LEDs on your board, this resistor is not needed|
100
|R6|1K|Z Axis Pololu Microstepping Pull-UP| |Only for machines with Z-Axis and Pololu|
101
|R7|2K2|I2C|X|Only for machines with I2C display|
102
|R8|2K2|I2C|X|Only for machines with I2C display|
103
|R9|10K|Z Axis Pololu Microstepping Pull-Down| |Only for machines with Z-Axis and Pololu|
104
|R10| |J14 AIN Pull-UP| |Only needed if J14 is used|
105
|R11|1K|Y Axis Pololu Microstepping Pull-UP|X|Only needed on machines with Pololu|
106
|R12| |J14 AIN Pull-Down| |Only needed if J14 is used|
107
|R13|10K|Y Axis Pololu Microstepping Pull-Down| |Only needed on machines with Pololu that do not do full microstepping|
108
|R14|1K|X Axis Pololu Microstepping Pull-UP|X|Only needed on machines with Pololu|
109
|R15|1K|J27 Analog output signal| |Only if J27 is used|
110
|R16|10K|X Axis Pololu Microstepping Pull-Down| |Only needed on machines with Pololu that do not do full microstepping|
111
|R17|1K|J27 Analog output signal| |Only if J27 is used|
112
|R18|10K|YHOME Pull-UP|X||
113
|R19|10K|XHOME Pull-UP|X||
114
|R20|1K|E Axis Pololu Microstepping Pull-UP| |Only for machines with E-Axis and Pololu|
115
|R21|10K|ZMIN Pull-UP| |Only for machines with Z-Axis|
116
|R22|10K|ZMAX Pull-UP| |Only for machines with Z-Axis|
117
|R23|1K|ZMAX OPTO| |Only for machines with Z-Axis|
118
|R24|1K|ZMIN OPTO| |Only for machines with Z-Axis|
119
|R25|10K|E Axis Pololu Microstepping Pull-Down| ||
120
|R26|1K|XHOME OPTO|X||
121
|R27|1K|YHOME OPTO|X||
122
|R28|330|Exhaust OPTO|X|All machines, because exhaust out is used for PWM right now!|
123
|R29|330|Laser Enable OPTO|X|Not in use, but advise to solder it in anyway!|
124
|R30|1K|5V Power LED|X|If you do not want LEDs on your board, this resistor is not needed|
125
|R31|330|Laser PWM OPTO|X||
126
|R32|330|Laser ON OPTO|X||
127
|R33|1K|AIN voltage divider| |Only if AIN is in use|
128
|R34|100|AOUT current limit| |Only if AOUT is in use|
129
130
h3. Capacitors
131
132
Place the capacitors:
133
134
|_.Number|_.Value|_.Function|_.Comment|
135
|C1|100 nF|Magjack noise filter||
136
|C3|100 nF|VMOT noise filter||
137 5 KalleP
|C4|1000 uF Elec|VMOT buffer|make sure the + goes through the square hole.|
138 1 jaap
|C5|100 nF|AIN noise filter|Can be omitted if AIN is not used|
139
|C6|100 uF Elco|VCPU Buffer|make sure the + goes through the square hole.|
140
|C7|22 nF|VCPU noise filter|Can be omitted if no voltage regulator (7805) is used|
141
|C8|100 nF|+5V noise filter||
142 5 KalleP
|C9|100 uF Elec|Step motor filter|make sure the + goes through the square hole.|
143
|C10|100 uF Elec|Step motor filter|make sure the + goes through the square hole.|
144
|C11|100 uF Elec|Step motor filter|make sure the + goes through the square hole.|
145 6 hugomeiland
|C12|100 uF Elec|Step motor filter|make sure the + goes through the square hole.|
146
|C13|22 nF |5V to 3.3V voltage regulator||
147
|C14|22 nF |5V to 3.3V voltage regulator||
148 1 jaap
149 5 KalleP
150 1 jaap
h3. LEDS
151
152 5 KalleP
Place the 3 leds, matching the flat side of the LED with the flat side of the led-drawing on the pcb. It's hard to see, but there is a flat side on the circles! It turns out that it is always towards the closest edge of the board.  Also some LEDs have no flat at all, the shorter leg is the one on the flat side (the cathode or negative).
153 1 jaap
154
h3. USB connector and network connector
155
156
Place the USB and network connector. The USB is currently not used, so it's optional.
157
158
h3. Connectors
159
160
Choose connectors that fit your laser best. Examples:
161
162
h4. Default configuration 
163
164
* 7 4-pin phoenix connectors:
165
** X, Y, Z connectors (J24, J18, J9)
166
** XY endswitch, Z-/Z+ endswitch (J34, J29)
167
** Laser P1,P2 (J37)
168
** PWM out (J27)
169
* 3 2-pin phoenix connectors
170
** Laser P4 (J39)
171
** Power supply (J38)
172
** Cover lid switch (J14)
173
* 1 5-pin phoenix connector (which is actually not in use at all!)
174
** J33
175
* 1 4-pin header
176
** I2C (J10)
177
178
h4. HPC LS-3020
179
180
* 4-pin JST connector on Y-axis (J18)
181
* 4-pin JST connector on J38 (laser ON/PWM)
182
* flatcable connector on P1 (X-axis, X+Y endstops)
183
* 3-pin Phoenix/Wuerth connector on J5 (Power)
184
* 4-pin JST connector on J10 (I2C)
185
186
h4. HPC LS-3020 Pro
187
188
* 4-pin JST connector on Y-axis and X-axis (J18, J24)
189
* 4-pin JST connector on J38 (laser ON/PWM)
190
* 4-pin JST connector on J34 (X+Y endstops)
191
* 3-pin Phoenix/Wuerth connector on J5 (Power)
192
* 4-pin JST connector on J10 (I2C)
193
194
h3. Transistors
195
196
* Solder in the two Darlington PNP Transistors (optional)
197
198
h3. Powering the board
199
200
The board offers several options for getting power:
201
202 5 KalleP
h4. Variable options
203 1 jaap
204
* J38 can be used to connect power for the board. The input power should be between 5 and 12 volts. If the power level is exactly 5V, the 7805 can be omitted and should be short-circuited with a wire between pole 1 and 3. If the power is higher then 5V or coming from a cheap adapter, using the 7805 is recommended.
205
* J5 can be used as a two-pole connector for VMOT (motor power for Pololu steppers). It can also contain the board input power on the 3rd pole, but then J38 should be omitted.
206 5 KalleP
* Finally, J5 can be used to supply the same supply voltage to the CPU AND for motor power to the steppers by making a jumper wire on the connector just above J5 (next to the legend "exhaust enable").
207 1 jaap
208
h4. HPC 3020 laser
209
210
The HPC laser comes with a plug with 5V and 24V combined. This can be connected to J5. The 7805 should be omitted and replaced by a jumper wire between pole 1 and 3.
211
212
h3. R10 and R12 resistors
213
214
Depending on the use of J14 and the power on VMOT, determine the correct values for R10 and R12. 
215
216
h3. Power Jumpers
217
218
The board contains 2 extra power jumpers to select power on inputs
219
220
h4. VEndstops Voltage selection
221
222
Place pin header on J43 for voltage selection on the sensors. This is the four-pin T-footprint near the endstop terminals.
223
For HPC LS3020, connecting the middle pin with +5V with a wire will do.
224
 
225
h4. VSensor (J27) Voltage selection
226
227 5 KalleP
The second power jumper is a 3-pin jumper labelled VCPU/VSENSOR/5V. It is located between the MBED and the 7805 regulator position close to a 100 uF capacitor. This can be connected in two ways:
228
* VCPU -> VSENSOR: use VCPU (usually +3.3V) as the supply for the sensors.
229
* 5V -> VSENSOR: use +5V as the supply for the sensors.
230 1 jaap
Connect only one of the outer pins with the middle pin at the same time!
231
232
h3. PWM Output select jumpers
233
234 5 KalleP
01SRC/02SRC: select which PWM value is selected for output via the transistors.
235 1 jaap
236 2 jaap
h2. Testing the board
237
238
h3. Visual double check
239
240
Check your board without power, to see if everything is al right
241 5 KalleP
* Visually check all solder joints
242
* Check all soldered wire-bridges and jumper settings
243 1 jaap
244
h3. Power check
245 2 jaap
246
*First remove the MBED, SDCARD, POLOLUs, OPTO-COUPLERS*
247 1 jaap
248 2 jaap
h4. Power check 1
249
250 5 KalleP
* Apply power (CPU and motor).
251 2 jaap
* Now check the voltages on the pins of the MBED (5V on pin 2, no voltages on other pins)
252 5 KalleP
* Check Vmotor (usually 24V) on the Pololus
253
* Check ground connections on Pololus (by measuring between 5V and those pins) 
254 2 jaap
255
h4. Power check 2
256
257 5 KalleP
* Disconnect power 
258
* Insert the MBED (with USB connector towards network connector)
259
* Connect the MBED to your PC or USB hub with the USB cable
260
* Check all 3.3V logic supplies to:
261 2 jaap
** Pololus
262
** Opto-couplers
263
** SD-card
264
265
If you are absolutely sure all power connections are OK, install the other components and proceed with the functional tests. 
266
267
*WRONG JUMPER CONNECTIONS OR BAD SOLDERING CAN CAUSE YOUR COMPONENTS (OR EVEN YOUR COMPUTER) TO START SMOKING AND CAUSE A LOT OF DAMAGE, MAKE SURE YOU CHECK AND DOUBLE-CHECK EVERYTHING BEFORE CONNECTING THINGS*
268
269 5 KalleP
h3. Insert the OPTO-Couplers
270 2 jaap
271 5 KalleP
The KB847 chips have a tiny line on one side. With the notch on the top, this is the left side of the chip. So on OPTO-IN, the line should be on the side of the SD card. On OPTO-OUT the line should be on the side of the MBED. 
272 2 jaap
273 3 jaap
Put the Opto-coupler IC's in place, and the CAN chip and test again. Place a (max 2GB) SD card. 
274 2 jaap
275 5 KalleP
h2. Test firmware
276 1 jaap
Now you should be ready to load the [[TestFirmware]]