2 - for packaging a board to attach to a computer on the ground station side, I
3 have a Hammond box that looks good. Digi-Key part number HM380-ND, $2 in
8 - rewire P1_2 to be CS* for the SPI EEPROM instead of accel_st, ground ST pin
10 - USB connector shouldn't hang over the edge of the board
11 - reorder debug connector pinout to match what actually works with cp2103
12 - make USB connector a dual footprint to allow remoting using another connector
13 like the one we're using for serial port from the tiny series?
14 - change debug header to 5 pins so we can use one board to program another
15 by bringing a gpio over to drive reset? 5-pin connector from tiny series.
18 - Keith would like to use SPI to talk to TelePyro and TeleTerra boards, so
19 we're thinking of giving up an LED to get a second chip select line, and
20 reusing the existing SPI channel to the memory chip. Now, how do we do an
21 input interrupt from the PIC to flesh out a 7-pin connector?
23 rename net cs0 to cs_mem to reduce confusion
24 lose second LED attached to CPU, P1_1 becomes cs_ext
25 lose R12 since LED is no longer there
26 add J9, 7 pins, Molex pn footprint=530470710 digikey=WM1736-ND
27 define 'interrupt' as a new net ... now, how to hook it up?
29 So the problem is how to multiplex one cc1111 pin to be bidirectional. If
30 the cc1111 asserts that pin, we need the PIC cs input to go low. If the
31 cc1111 isn't asserting it (switched to input), then we want the state of
32 the PIC interrupt output to be reflected there. But how can we drive the
33 cc1111 input while simultaneously knowing when it's being asserted as an
34 output? Doesn't seem possible. How does the Dallas 1-wire stuff work?
37 - based on experiences and discussion at Mile High Mayhem, here's what we
38 think we want to do at the schematic level:
40 + known changes for two cuts and jumps and two added resistors
41 + lose the temp sensor
43 + lose the 4-pin serial port connector
44 + change the debug connector to 4 pins 1.25mm ala deleted serial port
45 + add 7-pin 1.25mm connector that extends SPI for TT/TP and doubles
46 as debug control port for flashing another board with 7-4 pin cable
47 gnd, v_lipo, mo0, mi0, c0, cs1 (ex temp), irq1 (ex beeper)
49 + wire v_lipo to the igniter fets directly
50 + include a connector for an external pyro battery
51 + add one or two 1206 caps between +3.3V and gnd to ballast against
52 power switch bounce and/or brown-out on igniter firing:
54 DK 490-4512-1-ND is a 100uF 1206 part, 1.32 in 100 pieces
55 DK 445-1428-1-ND is a 47uF 1206 part, 0.91 in 100 pieces
57 + add MN5010HS GPS chip, chip antenna, and associated circuitry
59 BAS16 is DK BAS16LT3GOSCT-ND, SOT-23-3, 0.05 in 100 pieces
60 BSS138 is DK BSS138LT1GOSCT-ND, SOT-23-3, 0.14 in 100 pieces
61 33nF cap for antenna is DK 490-1315-1-ND, 0402, 0.03 in 100s
64 - after more thinking about this, I want to add the serial connector back in
65 but as an optionally loaded part ... if I can make it fit.
67 - can I put the GPS chip antenna on the board *and* allow for an SMA or other
68 connector if we want it off-board?
70 - changing the memory part from the SOIJ8 to the DFN8 would save about 2mm
71 in width, but that doesn't really help.
72 - changing the 5V switcher from S8 to MS8 takes us from 5 tall to 3 tall, but
73 costs $0.30 more per piece and isn't stocked by Digikey. Not worth it?
75 - noticed the NXP SC18IS600, which is an SPI slave to I2C master interface
76 with a few GPIO lines... mate that with an HMC5843, which is a 3-axis
77 magnetic sensor, and we might have another interesting companion board for TM
83 - add serial connector back to schematic as optionally loaded part
84 - move USB connector on PCB layout 80 mils in from board edge
85 - move yellow LED and passives closer to LiPo connector
86 + create PCB footprint for the GPS module
87 + create PCB footprint for the GPS antenna
projects / hw / telemetrum / blob