I have an esp14F. I mount it using spring contacts into a special programmer. When so loaded the pair ESP & programmer act like a normal NodeMCU with its own micro-USB connector.
The device has a sketch uploaded in it that measures a pressure sensor and displays it on an Oled, with one special feature – after it completes its tasks, the last thing it does it goes into eternal Deep Sleep. I can even use the USB connector to attach it to an ordinary phone charger, for power only.
I can restart the sketch two ways: by unplugging it and plugging it in or I can use the RST button. As long as it is in the programmer is always starts.
If I take the ESP14F out of the programmer and connect batteries through an MCP-1700 voltage converter to achieve 3.2 v to the unit (See the attached drawing), it will not run. I have tried connecting the 3.2v on and off. I’ve tried using the RST switch but these attempts will not make the ESP start & run.
Do you have any suggestions for me?
Can you add the following connections to your circuit?
- Enable (EN) pin to 3.3 (the power source)
- GPIO 15 to GND
And see if that solves the problem?
I’m not sure if you also need to connect GPIO2 to VCC using a resistor (I’m not sure if the ESP14F has that circuit built-in).
Read more about these connections here: https://github.com/espressif/esptool/wiki/ESP8266-Boot-Mode-Selection
Then, let me know if it worked.
The esp 14F Runs on batteries!!!! Your advice was perfect.
Sarah, you and Ruis are the greatest. The way you support your forum people is amazing. I never get useful response from the ESP8266 forum. Most of the time there is no response, then when I do, it’s usually some smart-aleck put down.
You can close this topic.
I’m really happy you got it working! 😀
I’ll close this question.
If you need further help, just open a new question.
“Hi Sarah. See the attached image for details.
I took your advice for added connections to the ESP 14-F to run on batteries. When I connected EN directly to 3.3V & IO15 directly to GND, I got a huge amount to battery current.
By connecting EN with a 10K resistor (instead of direct connection) to 3.3 volts, and IO15 with a 10K resistor (instead of direct connection) to GND, I was able to cut the battery current to 77 mA.
Taking the pressure sensor & the display out of the circuit I cut the current to 69 mA.
Also, the IO2 connection to 3.3V was not needed.
Apparently the 69 mA is just the current draw for the 14-F to do minimum tasks. This seems excessive.
Question: Is that due to the WiFi transmission capability, which we are not using in this application. If so, is there another processor we could use that draws much less current and can be programmed using Arduino?”
The power consumption you’re getting is for when the ESP is doing what task?
If you use deep sleep between tasks, you can decrease the power consumption.
When it comes to other development boards: the TinyPico achieves very good results in terms of consumption (only 18 µA in deep sleep.) I haven’t experimented with this board and I don’t know how much it consumes in active mode. But it may be worth taking a look at it: https://www.tinypico.com/