Tag Archives: Pi WIFI and ESP-12 GPIO.

Monday Morning at the Lab

Just in case anyone in the UK or EU is even remotely interested, I just put up my little pocket scope on Ebay. http://www.ebay.co.uk/itm/231492939705

Meanwhile talking of Ebay, the Raspberry Pi is currently working a treat on THIS little number…. a cheap WIFI dongle.  http://www.ebay.co.uk/itm/331400872324 –  it’s been running overnight and logging temperatures without a hitch. For under £4 that can’t be bad.  I’m thinking, once I get the Pi and the ESP8266 boards properly communicating over MQTT of putting a display on the Pi and making that the wall unit rather than hiding it away. Well, clearly, I’d rather NOT have to have a network cable going up the wall so the WIFI dongle solves a problem.

my ESP-12 units turned up – still waiting for some little adaptor boards to come that give you 0.1” pitch from the ESP-12s for experimenting.  It seems that it is necessary to ground GPIO-12 as well as taking the PD line high permanently – and I had confirmation yesterday that using GPIO-0 with a ground-based setup (for example an NPN transistor and resistor arrangement is NOT a good idea – personally I’ve been using then to power solid state relays taking the other side of the relay to positive hence ensuring a small amount of positive voltage at power up – and I’ve had no problems.  I plan also to tie GPIO16 to the external reset so I can experiment with the low power sleep mode. All of that late this week when my adaptors arrive.

Oh, I knew there was something else. Has anyone doing C coding with ESP8266s used this yet? Seems like a fine way to mess with ESP8266 GPIOs – giving you a consistent interface to handle GPIO 0,2, 4,5, 12,13 and 14. The author says he HAS used this with SDK 0.9.5 so it is pretty much up to date. As soon as I get my adaptors for the ESP-12s I’ll give it a good thrashing.  https://github.com/eadf/esp8266_easygpio