iot-arduino-ioexpander-esp8266-controller-twi

arduino nano as ioexpander controlled by esp8266 through TWI

• browser page
• requirements
• features
• setup
• advertisement
• api ( esp8266 controller )
• api ( arduino nano slave )

browser page

requirements

• esp8266 nodemcu
• arduino nano V3

setup

• schematics

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Take care not to set as output ports connected to ground ( reference )

features

• imagemap of arduino nano ports
• index.htm, app.js, image.png served by esp8266 ( encoded into flash by gen-h )
• scalable TWI slave devices
• control arduino nano port mode and value ( read, write ) from esp8266 through TWI

HTTP api ( esp8266 controller )

• busaddr : slave twi bus address
• portstr : one of "D2", "D3", "D4", "D5", "D6", "D7", "D8", "D9", "D10", "D11", "D12", "D13", "A0", "A1", "A2", "A3"
• mode : 0 (input) - 1 (output) - 2 (input pullup)

api	description	result example
/api/scan	list of twi slave devices addresses (dec)	[8,19]
/api/getportmodes/busaddr	retrieve port mode 0=input, 1=output, 2=input_pullup of slave at addr ports	[{ "port": "D2", "mode": 0 },...,{ "port": "A3", "mode": 0 }]
/api/getportvalues/busaddr	retrieve port value ( digitalRead )	[{ "port": "D2", "value": 0 },...,{ "port": "A3", "value": 0 }]
/api/setportmode/bus/portstr/mode	change port mode ( pinMode )
/api/setportvalue/bus/portstr/value	change port value ( digitalWrite )

TWI api ( arduino nano slave )

• note : subsequently to get twi calls master should request result

api	description	request example
getportmode portstr	retrieve port mode (0,1,2)	0
setportmode portstr mode	set port mode (0,1,2)
getportvalue portstr	retrieve port value	1
setportvalue portstr value	set port value