NodeMCU Current Monitoring

[dirtbikr]

Hi all!

I'm in the process of getting my project up and running and I'm having trouble monitoring the current being used. When I hook up my NodeMCU board using the 3.3v pins (with a 10uF capacitor on the bread board power rail) using a single LiPo 18650 and this (https://www.adafruit.com/product/2745) voltage regulator the board boots and I can access it via WiFi.

When I put my multimeter in between the positive lead of the battery and the input to the voltage regulator the NodeMCU board blinks brightly once (normal) and the current is about 140mA for two or three seconds. After this the little blue light blinks slowly about five or six times and the current jumps up to about 200mA and the blue light stops blinking. I can't access the board at this time and nothing seems to work.

I have tried multiple capacitor values (on the input to the nodeMCU board) and none seem to smooth it out. Is there something unique to the nodeMCU board that could cause this? My final design will be using and ESP07 but Iwanted to figure this out before I build that board.

Thanks!

[Drum]

I don't think the Node MCU is intended to be used this way and it does have a lot of things which I think could be an issue, but not being an Electrical Engineer, I don't know. NodeMCU is great for working out the software and connections (be careful with ADC though, see the schematic). Mostly this is because with a good USB power supply it runs pretty stable Try an ESP-7 on one of those really cheap white breakout boards to measure the voltage. Nut breadboards don't work so well. That may be another problem, breadboards really suck. I have a NodeMCU on a breadboard with DHT-22, DS18b20 and a LCD Display which can run for several weeks with no problems, but breathe on it wrong and it will start resetting every few minutes. For a really basic proof of concept I will use a breadboard, but for testing I am using prototyping boards. I would use one of those and maybe a INA219 to monitor current and voltage. I am working on a PCB design, but that is a ways off. Prototype boards are ugly, but far more stable if done well. I also use pins / headers to attach the ESPs, not soldering them to the board, everything can be stripped off pretty easily except caps, resisters and some connectors. Those have to be unsoldered.

Also make sure you are not grounding the "EN" pin on your LM3671, that is unlikely, but would explain the problem.. I have a few of those as well. I haven't had any problems with that board, running off 1 X 3.7v LiPo (5000mAh) or 4 x 1.2v NiMh. Both have been running for several months with solar cells to charge the batteries. I just received a few INA291s so that is on the list to test as well, so i can get a better idea of what is going on with the battery and the solar cells, rather than just voltage from either via ADC. I am using the cheap pre-wired red 2 pin plugs for all my power connections so I can make changes easily.

[JR01]

Check this cool device the electronic engineer is busy building with the brand new ATM90E26, he has a previous version with ESP8266, and have promised me to try SPI with ESP8266 with tuis new energy monitoring chip.

http://whatnicklife.blogspot.com/2016/0 ... akout.html.

I hope he gets it right, I need one.