lecture 8 micromouse pcb design guide
DESCRIPTION
Lecture 8 Micromouse PCB design guide. Components Placement. Place library for encoder/motor to (0,0) to make it symmetrical from left and right Draw a middle reference line. Use dimension layer to draw the outline of the mouse, make sure the length is not exceed 100mm to save cost. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Lecture 8 Micromouse PCB design guide](https://reader033.vdocuments.us/reader033/viewer/2022061614/56814b58550346895db84f81/html5/thumbnails/1.jpg)
Lecture 8
Micromouse PCB design guide
![Page 2: Lecture 8 Micromouse PCB design guide](https://reader033.vdocuments.us/reader033/viewer/2022061614/56814b58550346895db84f81/html5/thumbnails/2.jpg)
Components Placement
![Page 3: Lecture 8 Micromouse PCB design guide](https://reader033.vdocuments.us/reader033/viewer/2022061614/56814b58550346895db84f81/html5/thumbnails/3.jpg)
• Place library for encoder/motor to (0,0) to make it symmetrical from left and right
• Draw a middle reference line
![Page 4: Lecture 8 Micromouse PCB design guide](https://reader033.vdocuments.us/reader033/viewer/2022061614/56814b58550346895db84f81/html5/thumbnails/4.jpg)
• Use dimension layer to draw the outline of the mouse, make sure the length is not exceed 100mm to save cost
![Page 5: Lecture 8 Micromouse PCB design guide](https://reader033.vdocuments.us/reader033/viewer/2022061614/56814b58550346895db84f81/html5/thumbnails/5.jpg)
• Draw the guide line for the wall and posts in order to determine the sensor point angles later
![Page 6: Lecture 8 Micromouse PCB design guide](https://reader033.vdocuments.us/reader033/viewer/2022061614/56814b58550346895db84f81/html5/thumbnails/6.jpg)
• Place the components at proper position
• Place sensors at proper position, make sure they point to proper location
• Make sure the components won’t be blocked by motor mount/encoder
![Page 7: Lecture 8 Micromouse PCB design guide](https://reader033.vdocuments.us/reader033/viewer/2022061614/56814b58550346895db84f81/html5/thumbnails/7.jpg)
Where should sensors point to?• Side sensors point to
somewhere a little to the front of the post, when the mouse is at the center of the cell
• Front sensors point outwards about 5-10 degrees, make so it won’t point to the side of the wall when at 1.5 cells away
![Page 8: Lecture 8 Micromouse PCB design guide](https://reader033.vdocuments.us/reader033/viewer/2022061614/56814b58550346895db84f81/html5/thumbnails/8.jpg)
PCB drawing
![Page 9: Lecture 8 Micromouse PCB design guide](https://reader033.vdocuments.us/reader033/viewer/2022061614/56814b58550346895db84f81/html5/thumbnails/9.jpg)
Settings• No mask for via>12 mills• Make 1 mill grid when drawing
and parts placing
![Page 10: Lecture 8 Micromouse PCB design guide](https://reader033.vdocuments.us/reader033/viewer/2022061614/56814b58550346895db84f81/html5/thumbnails/10.jpg)
Traces• MCU pins from
LQFP package are 10-12 mill wide.
• Try maximum tracer width for power/analog signal related trace
• Thinner traces are OK for digital signal
![Page 11: Lecture 8 Micromouse PCB design guide](https://reader033.vdocuments.us/reader033/viewer/2022061614/56814b58550346895db84f81/html5/thumbnails/11.jpg)
Trace thickness
• Wider trace for high power intensive parts, ex. Vbat Power trace
• Thinner for signal traces
• Polygon may needed to give more area for power trace for thermo performance
![Page 12: Lecture 8 Micromouse PCB design guide](https://reader033.vdocuments.us/reader033/viewer/2022061614/56814b58550346895db84f81/html5/thumbnails/12.jpg)
Trace style
• good• bad
• Shorter the possible• Less turn possible• 45 degree turns
![Page 13: Lecture 8 Micromouse PCB design guide](https://reader033.vdocuments.us/reader033/viewer/2022061614/56814b58550346895db84f81/html5/thumbnails/13.jpg)
Small via
• 12 mill via minimum• Good for signal trace• Better be masked
![Page 14: Lecture 8 Micromouse PCB design guide](https://reader033.vdocuments.us/reader033/viewer/2022061614/56814b58550346895db84f81/html5/thumbnails/14.jpg)
Large Via• Larger via for
power/thermo intensive trace/pad/polygon
• Should not be masked
• Drill shouldn’t bee too big
![Page 15: Lecture 8 Micromouse PCB design guide](https://reader033.vdocuments.us/reader033/viewer/2022061614/56814b58550346895db84f81/html5/thumbnails/15.jpg)
Polygon
• First to the First: Don’t make a single GND polygon for the entire PCB!!!!!
• Why? Because it will transfer heat to temperature sensitive components easily from some heat intensive parts
• You should place polygon selectively, only on those parts generate a lot of heat(5V LDO, motor driver) or the parts are sensitive with heat(MCU, analog device)
![Page 16: Lecture 8 Micromouse PCB design guide](https://reader033.vdocuments.us/reader033/viewer/2022061614/56814b58550346895db84f81/html5/thumbnails/16.jpg)
Sample 1
• Motor driver, GND polygon, on both sides
![Page 17: Lecture 8 Micromouse PCB design guide](https://reader033.vdocuments.us/reader033/viewer/2022061614/56814b58550346895db84f81/html5/thumbnails/17.jpg)
Sample 2• Not make the polygon connected
between 5V and MCU since MCU is temperature sensitive
![Page 18: Lecture 8 Micromouse PCB design guide](https://reader033.vdocuments.us/reader033/viewer/2022061614/56814b58550346895db84f81/html5/thumbnails/18.jpg)
Distincted Ground
• MGND• DGND• AGND• Don’t mix them before they reach the
negative terminal of battery• AGND is temperature sensitive, make the
trace avoid the hot area if possible
![Page 19: Lecture 8 Micromouse PCB design guide](https://reader033.vdocuments.us/reader033/viewer/2022061614/56814b58550346895db84f81/html5/thumbnails/19.jpg)
MGND
![Page 20: Lecture 8 Micromouse PCB design guide](https://reader033.vdocuments.us/reader033/viewer/2022061614/56814b58550346895db84f81/html5/thumbnails/20.jpg)
DGND
![Page 21: Lecture 8 Micromouse PCB design guide](https://reader033.vdocuments.us/reader033/viewer/2022061614/56814b58550346895db84f81/html5/thumbnails/21.jpg)
AGND
![Page 22: Lecture 8 Micromouse PCB design guide](https://reader033.vdocuments.us/reader033/viewer/2022061614/56814b58550346895db84f81/html5/thumbnails/22.jpg)
Questions?