- Sun Dec 04, 2016 10:29 am
#59086
And that is why I didn't reply earlier. Because I don't know how the supplied AT mode program works. And I'm sure that is the case with a lot of people. So yes you could get a lot of views (including Google and other Bots) and no replies.
- Sun Dec 04, 2016 11:42 am
#59088
Hi,
3.7v lipo and a ams1117 3.3v is a very bad combination. The AMS1117 has a dropout voltage of about 1V @800mA (max 1.3V). This means that the input voltage has to be 1v higher then the output voltage, otherwise the regulator can't regulate probably which results in a lower output voltage. Best use a multimeter to verify the esp8266 gets the 3.3V you think.
Another reason why the ams1117 is a bad choice is it's high quiescent current.
You need to get a different voltage regulator to power the esp through a lipo.
I'm using the MCP1700 for my lipo battery powered (temp, humi,..) loggers. SPX3819, RT9013, AS1362, LT1763, (just the ones I've tested myself) also work great with a lipo but have a higher quiescent current. Not nearly as high as the ams1117 though.
I'v also seen people using HT7333 in battery powered projects. Other people don't use low dropout voltage regulator at all, instead they use switched voltage regulators (step-up and/or step-down).
There are many options. What's best depends on what exactly you want to do.
PS, if it can help someone:
To make the esp8266 works I'm using lipo battery 3.7V 800mA as source of power that I plug to am "ams1117 3.3v" that I connect to the esp.
3.7v lipo and a ams1117 3.3v is a very bad combination. The AMS1117 has a dropout voltage of about 1V @800mA (max 1.3V). This means that the input voltage has to be 1v higher then the output voltage, otherwise the regulator can't regulate probably which results in a lower output voltage. Best use a multimeter to verify the esp8266 gets the 3.3V you think.
Another reason why the ams1117 is a bad choice is it's high quiescent current.
You need to get a different voltage regulator to power the esp through a lipo.
I'm using the MCP1700 for my lipo battery powered (temp, humi,..) loggers. SPX3819, RT9013, AS1362, LT1763, (just the ones I've tested myself) also work great with a lipo but have a higher quiescent current. Not nearly as high as the ams1117 though.
I'v also seen people using HT7333 in battery powered projects. Other people don't use low dropout voltage regulator at all, instead they use switched voltage regulators (step-up and/or step-down).
There are many options. What's best depends on what exactly you want to do.
- Sun Dec 04, 2016 3:54 pm
#59095
I had used the MCP1700 with a 5 volt input. I had thought it should have been a good choice but I found that it is marginal for the ESP. While it is rated for 250mA it can supply higher current at a low duty cycle. But I was still getting the occasional resets. I thought it was due to flaky code. I did some investigation at work and found that I would get some short negative voltage glitches that disrupted the ESP8266. I switched to a low drop linear regulator with a 500mA rating that we use in our products at work and the magnitude of the drops decreased. No more random resets.
8n1 wrote:I'm using the MCP1700 for my lipo battery powered (temp, humi,..) loggers.
I had used the MCP1700 with a 5 volt input. I had thought it should have been a good choice but I found that it is marginal for the ESP. While it is rated for 250mA it can supply higher current at a low duty cycle. But I was still getting the occasional resets. I thought it was due to flaky code. I did some investigation at work and found that I would get some short negative voltage glitches that disrupted the ESP8266. I switched to a low drop linear regulator with a 500mA rating that we use in our products at work and the magnitude of the drops decreased. No more random resets.
