From 4b443afa388ae88a7692818a2097c9c99f2ff4e5 Mon Sep 17 00:00:00 2001 From: Bdale Garbee Date: Sun, 10 Aug 2025 22:02:31 -0600 Subject: [PATCH] update offboard parts list, add some more notes to Notebook --- Notebook | 25 +++++++++ offboard.sch | 145 +++++++++++++++++++++++++++++++++++++++------------ 2 files changed, 136 insertions(+), 34 deletions(-) diff --git a/Notebook b/Notebook index 724cdc9..aa5db7a 100644 --- a/Notebook +++ b/Notebook @@ -537,3 +537,28 @@ a 7.5 second power button press will cause this thing to turn the power off regardless of the software state on the Pi. +2025.07.27 +- the stencil for v2p3 seemed to over-paste the large pads on the FETs. Might + want to shrink the paste feature on that footprint? + +2025.07.29 +- left the board running with USB-C cable attached to my LDNIO power supply. + found shut down the next morning with battery pack at about 8.4V. That makes + me think the IP2326, at least without data lines connected and on this power + supply, is not turning back on after it thinks the pack is "full" once? + Unplugging and re-plugging the cable caused the charger to start a slow + charge from this obviously-too-low battery charge state. With 1k from pin 7 + to ground we should be running with no ROT charging timeout. The IP2326 + docs say it should start charging again if the pack drops below 12V, so there + must be something odd about the LDNIO USB charger. + +- this also makes me think it might be worth adding a low-voltage cut-off to + the design. To do this in hardware would take another comparator, two + resistors to set a threshold, and the "spare" n-channel FET. Watch the + sense_batt line until it goes below the threshold, triggering the FET to + pull down the input of the existing n-channel FET in the soft power switch + circuit. Perhaps "good enough" would be to have the software watch for low + battery voltage and turn itself off when the system voltage drops below 11.1 + volts? I mean, on some level, the worst thing that happens is needing to + replace the 18650 batteries. + diff --git a/offboard.sch b/offboard.sch index 0463727..18c29f0 100644 --- a/offboard.sch +++ b/offboard.sch @@ -11,7 +11,7 @@ T 36800 18600 9 10 1 0 0 0 1 T 37300 18600 9 10 1 0 0 0 1 2 T 39200 18600 9 10 1 0 0 0 1 -v2p3 +v2p4 T 34900 19000 9 10 1 0 0 0 2 Copyright (c) 2025 by Bdale Garbee Licensed under the TAPR Open Hardware License @@ -21,7 +21,7 @@ T 24705 28201 5 10 0 1 0 6 1 device=OffBoard T 25805 28001 5 10 1 1 0 6 1 refdes=BOX2 -T 26200 28000 5 10 1 1 0 0 1 +T 26100 28000 5 10 1 1 0 0 1 value=Alarm Module T 25800 28000 5 10 0 1 0 6 1 mfg_part_number=GRB112A802BB @@ -30,43 +30,120 @@ vendor=digikey T 25800 28000 5 10 0 1 0 6 1 vendor_part_number=CW102-ND } -T 27900 28000 9 10 1 0 0 0 1 +T 28300 28000 9 10 1 0 0 0 1 siren with red LEDs -C 25800 26400 1 0 1 offboard.sym +T 28300 28300 9 10 1 0 0 0 1 +Hammond 1457N1201 extruded aluminum enclosure +C 25200 27600 1 180 0 resistor.sym { -T 24705 26601 5 10 0 1 0 6 1 -device=OffBoard -T 25905 26401 5 10 1 1 0 6 1 -refdes=BOX1 -T 26200 26400 5 10 1 1 0 0 1 -value=50 cal ammo box -T 25800 26400 5 10 0 1 0 6 1 -mfg_part_number=1554E2GYSL -T 25800 26400 5 10 0 1 0 6 1 -vendor=mosuer -T 25800 26400 5 10 0 1 0 6 1 -vendor_part_number=546-1554E2GYSL -} -T 27900 26400 9 10 1 0 0 0 1 -50-cal steel ammo box -C 25200 25000 1 180 0 resistor.sym -{ -T 24900 24600 5 10 0 0 180 0 1 +T 24900 27200 5 10 0 0 180 0 1 device=RESISTOR -T 25200 25000 5 10 0 1 180 0 1 +T 25200 27600 5 10 0 1 180 0 1 footprint=0.125W_Carbon_Resistor -T 25400 24800 5 10 1 1 0 0 1 -refdes=R106 -T 26200 24800 5 10 1 1 0 0 1 -value=374 +T 25800 27400 5 10 1 1 0 6 1 +refdes=BOX4 +T 26100 27400 5 10 1 1 0 0 1 +value=374 ohm } -T 27900 24800 9 10 1 0 0 0 1 +T 28300 27400 9 10 1 0 0 0 1 1/8w 1% through-hole gain-setting resistor -T 27900 23200 9 10 1 0 0 0 1 +T 28300 27100 9 10 1 0 0 0 1 Raspberry Pi Zero 2W -T 27900 22800 9 10 1 0 0 0 1 -U.FL connector for Pi -T 27900 22400 9 10 1 0 0 0 1 -U.FL to RP-SMA cable assembly -T 27900 22000 9 10 1 0 0 0 1 +T 28300 26200 9 10 1 0 0 0 1 RP-SMA WiFi antenna +C 25800 27700 1 0 1 offboard.sym +{ +T 24705 27901 5 10 0 1 0 6 1 +device=OffBoard +T 25805 27701 5 10 1 1 0 6 1 +refdes=BOX3 +T 26100 27700 5 10 1 1 0 0 1 +value=AC Outlet +T 25800 27700 5 10 0 1 0 6 1 +mfg_part_number=GRB112A802BB +T 25800 27700 5 10 0 1 0 6 1 +vendor=digikey +T 25800 27700 5 10 0 1 0 6 1 +vendor_part_number=CW102-ND +} +T 28300 27700 9 10 1 0 0 0 1 +Schurter 4300.0705 +C 25800 28300 1 0 1 offboard.sym +{ +T 24705 28501 5 10 0 1 0 6 1 +device=OffBoard +T 25805 28301 5 10 1 1 0 6 1 +refdes=BOX1 +T 26100 28300 5 10 1 1 0 0 1 +value=Enclosure +T 25800 28300 5 10 0 1 0 6 1 +mfg_part_number=GRB112A802BB +T 25800 28300 5 10 0 1 0 6 1 +vendor=digikey +T 25800 28300 5 10 0 1 0 6 1 +vendor_part_number=CW102-ND +} +C 25800 27100 1 0 1 offboard.sym +{ +T 24705 27301 5 10 0 1 0 6 1 +device=OffBoard +T 25805 27101 5 10 1 1 0 6 1 +refdes=BOX5 +T 26100 27100 5 10 1 1 0 0 1 +value=Pi Zero 2W +T 25800 27100 5 10 0 1 0 6 1 +mfg_part_number=GRB112A802BB +T 25800 27100 5 10 0 1 0 6 1 +vendor=digikey +T 25800 27100 5 10 0 1 0 6 1 +vendor_part_number=CW102-ND +} +C 25800 26800 1 0 1 offboard.sym +{ +T 24705 27001 5 10 0 1 0 6 1 +device=OffBoard +T 25805 26801 5 10 1 1 0 6 1 +refdes=BOX6 +T 26100 26800 5 10 1 1 0 0 1 +value=RF Connector +T 25800 26800 5 10 0 1 0 6 1 +mfg_part_number=GRB112A802BB +T 25800 26800 5 10 0 1 0 6 1 +vendor=digikey +T 25800 26800 5 10 0 1 0 6 1 +vendor_part_number=CW102-ND +} +C 25800 26500 1 0 1 offboard.sym +{ +T 24705 26701 5 10 0 1 0 6 1 +device=OffBoard +T 25805 26501 5 10 1 1 0 6 1 +refdes=BOX7 +T 26100 26500 5 10 1 1 0 0 1 +value=RF Cable +T 25800 26500 5 10 0 1 0 6 1 +mfg_part_number=GRB112A802BB +T 25800 26500 5 10 0 1 0 6 1 +vendor=digikey +T 25800 26500 5 10 0 1 0 6 1 +vendor_part_number=CW102-ND +} +C 25800 26200 1 0 1 offboard.sym +{ +T 24705 26401 5 10 0 1 0 6 1 +device=OffBoard +T 25805 26201 5 10 1 1 0 6 1 +refdes=BOX8 +T 26100 26200 5 10 1 1 0 0 1 +value=Antenna +T 25800 26200 5 10 0 1 0 6 1 +mfg_part_number=GRB112A802BB +T 25800 26200 5 10 0 1 0 6 1 +vendor=digikey +T 25800 26200 5 10 0 1 0 6 1 +vendor_part_number=CW102-ND +} +T 28300 26800 9 10 1 0 0 0 1 +U.FL for Pi board +T 28300 26500 9 10 1 0 0 0 1 +U.FL to RP-SMA cable assembly -- 2.47.2