1 <Igor2> bdale, the small radius corner arcs are easy:
2 <Igor2> they start at a 90 degree angle at the end of the vertical line
3 <Igor2> si I'd do this:
4 <Igor2> start with the vertical line
5 <Igor2> draw the 2 90 degree arcs connecting to the vertical line
6 <Igor2> then draw one large radius arc for the whole upper section and another for the whole lower section (you can use the propedit to set the exact radius, and you can use the vertical size specified in the drawing to tune the placement)
7 <SnakesAndStuff> Really stupid question... are the R345.40 arcs assumed to be referenced center to board?
8 <Igor2> if you did everything as above, then you will have the small, almost-90-degree arc crossing the large arc
9 <Igor2> and that's when you can use the trim action to cut off the excess part easily
10 <Igor2> this will guarantee the endpoint of the two arcs will be at the intersection
13 <bdale> Igor2: given a complex board outline, is there a quick way to create a plane that has copper to a given distance from the board edge everywhere?
14 <Igor2> bdale, you can copy the outline to copper nd mark the objects noexport
15 <Igor2> we even have an user script that can copy the outline to every (copper) layer and update it quickly if you change the outline
16 <Igor2> noexport: http://repo.hu/cgi-bin/pool.cgi?project=pcb-rnd&cmd=show&node=noexport
17 <Igor2> user script: http://repo.hu/cgi-bin/edakrill.cgi?cmd=show&krill=igor2/script/pcb-rnd/on_every_layer.krill
22 - for the LiPo charger LEDs, it might be nice to have them shine out through
23 a hole in the end adjacent to the connector, so that if you're plugging it
24 in it's easy to see them. If so, a right-angle SMT dual LED like the
25 Digikey 350-2072-1-ND (about price parity with our current dual LED) could
29 - included 40 PCC-SMP-CLIP on a Newark order so I'll have hold-down clips for
30 the connectors I acquired on eBay
32 - it turns out the board outline for the 1553BBK and 1553CBK are the same,
33 the latter is just thicker. The 1553BYLBK is a yellow with black edges
34 variant of the thinner one, and seems like the ideal choice for this project,
35 looks very "speed yellow" fast car'ish.
37 - adding BTLE module requires connecting:
39 P1_5(CONNECTED) bt_p1_5
40 P2_2(SW_BTN) bt_sw_btn
41 P2_3(WAKEUP) bt_wake_up
42 P3_1(RSSI_IND) bt_p3_1
51 - the MAX6675 turns out to be expensive .. $12.68 q1. The MX31855KASA+T
52 looks to be pin compatible and only $5.31 q1. The biggest difference
53 appears to be that the 6675 is 12-bit ADC and 16 bits of data per reading,
54 while the 31855 is 14-bit and sends 32 bits per reading. Let's try them!
57 - samples of possible tire pressure sensors made by Fujikura arrived from Kim
58 Solomon at ServoFlo. What came are 4 pieces of APB20R-001MG, and 2 pieces of AH30R-050KG-X1.
60 The APB2 series are the parts Kim suggested for my application, have a
61 barbed port, and these are 1MPa parts. However, right now they only have
62 them in 5V. Should have more 3.3V parts eventually, but sent these so
63 I can thy them out with an Arduino or something. The big problem I see is
64 that the barb comes off orthogonal to the PCB surface, so using them would
65 make for a "thick" case need.
67 The AH3 series are quite similar, but smaller, and have the barbless port
68 coming off parallel to the PCB surface. The parts available to send as
69 samples are 5V and 500 kPa. Unfortunately, the AH3 line is down at Fujikura
70 due to a fire at the ASIC supplier, plans call for the AH3 series to be
71 available again in mid-2022.
73 In both cases, these are 6-lead DIP'ish through-hole parts, with only 3 pins
74 active (power, gnd, analog output), and are "Gauge/Positive" parts.
76 The AH3 line is down at Fujikura due to a fire at the ASIC supplier, plans
77 call for the AH3 series to be available again in mid-2022. If the APB2
78 series seems like an acceptable fit otherwise, then it could just be a crazy
79 mechanical hack would allow the part to be mounted so the barb is parallel
80 to the board surface somehow? Maybe a small carrier board? Much study
84 - sent Kim at Servoflo a query about AH31R-001MG availability (3.3V, 0-150psi)
86 This pressure sensor has an analog output of 0.3 to 3.3V from 0-150psi, so
87 with a 12-bit ADC running 0 to 3.3V, the psi per q-level of the ADC is about
88 0.05, so we should "easily" be able to record pressure to the nearest tenth
89 of a psi. Seems sufficient.
91 Interestingly, the sensor also has a threshold comparator. For the price
92 of 2(3?) resistors, I could set a threshold that I could sense the state of.
93 That might allow knowing when a pressure is applied to make it possible to
94 record a pressure without having to push a button on the UI? Maybe set it
95 for something like 20 psi? When that triggers, average some number of ADC
96 input readings, record it and beep? Vth needs to be 0.66V for 20psi,