ESP8266 Community Forum

- Wed Sep 16, 2015 12:38 am #29129

The schematic [...] shows 4 GPIO I2C expander and ESP-01.

As far as I can tell, it doesn't have an "automatic reset" provision. The switch S4 has to be pressed while resetting the ESP-01 go get it in download mode. The benefit of the automatic reset circuitry is that the download utility can get the device into download mode by manipulating serial port lines (different methods use different combinations of DTR, RTS and/or sending a break).

Don Kinzer
ZBasic Microcontrollers
http://www.zbasic.net

- Wed Sep 16, 2015 12:49 am #29130 My FTDI exposes the 5v line from the USB connection; I attached a small DC-DC converted (it's based on a LM2596, and costs less that 1$ on eBay) and have been powering a ESP-01 without issues.

I also found a bit discouraging that both GPIOs exposed on the ESP-01 are used to select the booting mode. Now, using an external GPIO expander is probably a good idea on some projects, but in my case upgrading to a ESP-12 seems more interesting.

- Wed Sep 16, 2015 8:59 am #29158 On the power front, I'm going to have to come up with something. I thought that the MB102 would make it easy, but without an appropriate wal-wart or male-male USB cable... If I can't find a wal-wart nearby, I'll just have to wait for the cables to arrive (ordered last night), I might have to rig something up. Then again, there is always batteries. I really hate having to employ a breadboard just to get the darn thing powered and programmed. Making it convenient to program goes a long way to encouraging one to fiddle. Not complaining. Just saying I need to find/build something to make it convenient.

On the GPIO front, I wouldn't have ordered the ESP-01 if I had read Kolban's book before hitting EBay. The ESP-12 and a breadboard adapter are a better fit for getting started. There's also the issue of shielding.

My FTDI exposes the 5v line from the USB connection; I attached a small DC-DC converted (it's based on a LM2596, and costs less that 1$ on eBay) and have been powering a ESP-01 without issues.

I also found a bit discouraging that both GPIOs exposed on the ESP-01 are used to select the booting mode. Now, using an external GPIO expander is probably a good idea on some projects, but in my case upgrading to a ESP-12 seems more interesting.