ESP8266 Community Forum

- Sun Jan 29, 2017 7:44 am #61712 I have a custom designed board with an esp8266-12f. I want to upload new firmware but try as I might I cannot get it to yield its MAC address which seems to be a prerequisite for using The Node MCU flashing tool. Having tried all the commonly used baud rates and flash size options and ensuring I have a valid comes port the best I've achieved (using PUTTY to observe results) is to get 'waiting for host, reset cause 2, boot mode 7,7'.

Have I got a bad device, when and how does the MAC address get 'burnt' to the device? I have a digital scope, all the pre-requisites (GPIO15 grounded via resistor, GPIO02 pulled high through resistor, GPIO0 grounded for boot mode) look to be correct. I have 100uf tantalums both before and after the 3.3V (TPS77733) regulator.

- Sat Feb 04, 2017 9:17 am #62014 Problem solved. As is almost always the case, the problem was with the power source to the ESP8266. The design incorporated a battery charge controller MCP73871 powered by an 5V USB port. Whilst this could potentially source 600mA the charge controller limited the current. Connecting the battery allowed current demand in excess of that sourced by the co,nyroller to be provided by the battery. This, together with a 100 uF capacitor at both the input and output of the TPS77733 LDO seems to have rectified the problem.