Hi Daniel, Thanks for your response. On 1/28/20, Daniel Wagner <wagi@xxxxxxxxx> wrote: > Hi JH, > > On Mon, Jan 27, 2020 at 01:26:41PM +1100, JH wrote: >> It seems to me there are subtle differences between connman / ofono >> and OpenWrt netifd, could the connman / ofono require more rigid >> stable USB voltage than OpenWrt netifd? Or could the OpenWrt netifd be >> more superior than connman / ofono in terms of 4G LTE connections? >> >> Appreciate your insight comments and advice. > > What about measuring the power drawn by the device? And while at it > also careful check the datasheets of the components if the tolerances > of the hardware components are meet. I did current measuring, running ConnMan and oFono, the power consumption was about 150mA - 260mA, running OpenWrt netifd, the power consumption was about 150mA - 200mA. I have to say, the result might not be accurate (1) if I change the voltage slightly, the power consumption would be different; (2) The maximum current consumption changes from time to time; (3) The DC power has only one output and one current meter, I cannot connect both devices running in parallel. I'll find a DC power supply with two power output and 2 current / voltage meters, and to buy another debug cable to connect both devices in parallel. > I cannot comment on netifd since I don't know anything about it. But > it could be that ConnMan and oFono together do more CPU work hence the > device drains more power. I can tell you from experience if the CPU > doesn't get enough power you see really random crashes and weird > behaviors. Check the reports on Raspberry Pi and power supplies. Good to know that experience, it does help a lot. Thank you Daniel, Kind regards, - jh
