GeoNomad wrote:GeoNomad wrote:I will add a pullup on GPIO0 and try again. But GPIO0 low would normally enter flash programming mode, not zombie mode
I can confirm that awaking from sleep, GPIO0 low causes zombie mode and not UART flash mode, which is what happens on a power reset. Interesting that it is different and makes me wonder what else is different between a full power reset and a reset from sleep mode.
So, recommendation is now that both GPIO0 and GPIO2 MUST have pullups on them to reliably awake from node.dsleep(). 2K to 12K seem to be advised by different sources.
it is possible that UOTXD and MTD0 also require being pulled up or down for total reliability. I don't believe MTD0 has a connection on the ESP-01, but then the ESP-01 is not designed for sleep as there is no jumper for pin 8 to 32...
In an RF environment I'd like to keep the pins pulled pretty good. 10k+ seems to me to be on the high side. I mostly use 4k7 (or close to that) on the ESP8266 to be reasonably safe. 2k only if I consider it critical (e.g. exposed long pcb trace or wire on pin etc).
I have no problems anymore.Attached a screenshot of an ESP8266-03 recording its own battery voltage (LiPo w/ small solar cell). 1 min sampling and upload to server w/ deepsleep. (subtract approx. 0.2V because of GPIO for GND).