08-10-2020, 05:21 AM
(08-05-2020, 05:16 PM).lupyuen Wrote: Hmmm not sure why PineTime Updater would cause that to the Pi... Remember to connect/disconnect PineTime to Pi only when the Pi power is off.
It is probably also a good idea to have resistors in series between the boards on the SWDIO and SWCLK lines. Not only does this help absorb small differences in the reference voltages on the two devices but, more importantly, there have been a reports on the forum (and via other channels) of pad drivers blowing up when using the bcm2835spi driver for RPi (which IIUC deliberately permits both devices trying to drive SWDIO at the same time in order to meet the protocol timings). Sadly I have never been able to get a sufficiently clear bug report to be 100% sure that we are seeing physical damage from using directly connected wires but I certainly would never connect these devices without resisters inline.
Of course, if you have a PineTime dev kit and it is still running the stock firmware then I'd strongly recommend updating over-the-air using Bluetooth rather than trying to hook up an RPi.