Differences

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--- pis [2024/07/26 20:36] – river
+++ pis [2024/07/29 16:46] (current) – river
@@ Line 16: / Line 16: @@
 | RX | GND | TX |
 | SWCLK | GND | SWDIO |
+USB
 [[https://datasheets.raspberrypi.com/debug/debug-connector-specification.pdf]]
@@ Line 30: / Line 30: @@
 According to a forum post, will not power on itself if powered on GPIO pins. It can run, but needs power button pressed.
+===== USB =====
+==== Power Switching ====
+Switches, off then on, power to USB ports. Apparently you can't do them individually, but need to turn them all off to get any of them to go off.
+This needs a recent version of uhubctl - the version in Raspbian didn't work. I built from git.
+<code bash usb_powercycle>
+#!/bin/bash
+uhubctl -l 1 -a 0
+uhubctl -l 2 -a 0
+uhubctl -l 3 -a 0
+uhubctl -l 4 -a 0
+sleep 3
+uhubctl -l 1 -a 1
+uhubctl -l 2 -a 1
+uhubctl -l 3 -a 1
+uhubctl -l 4 -a 1
+</code>
+===== 3 =====
+==== Power ====
+Recommended 2.5A supply, but that includes max of 1.2A for USB ports, so 1.3A board. Type 500mA. With LoRa board, maybe 1.5A total needed at 5V.
+.5W.
+About 700mA max at 11V - i.e. a nearly empty lead acid battery powering the CAN bus. NMEA micro cables should be 22 AWG for power. ~62R / km, 124R with return. ~1R2 for 10 meters. Seems ok.