On 2019-11-17 13:29, Michael Balzer wrote:
Craig,
Am 17.11.19 um 19:31 schrieb Craig Leres:
On 2019-11-17 04:11, Michael Balzer wrote:
I also saw this & can also reproduce this on my workbench. What is the method to induce the problem?
No method. If the theory is right it depends on a combination of random circumstances if the MDM_EN signal is long enough for the modem to recognize.
I guess I was hoping for a way to wedge the modem so I could be sure if the resistor works.
I think something in the range 130-150K should work. That should put the base to ~0.5-0.6V for low and to ~1.0-1.2V for high. That's either not fully switched off on low or not fully saturated on high, but should be sufficient for the modem.
Not 100% sure I have time left this weekend but when I try this I'll try to grab some traces with my scope. Also my collection of smd resistors is modest so I'll have to use 1/8w axial to test. Craig