I2C Module

[sn2k]

The Module I2C module have a bug:
i2c.write is ok (PCF8574)
c=i2c.read(id,1) the mcu restart i have tried with SHT21, BMP180, TSL2561 , PCF8574 all FAIL

Please can you repair this? And have your examples to this I2C Devices?
Thanks a lot

[SmartArduino]

There is a example here:
https://github.com/SmartArduino/WiFiMCU/blob/master/Document/demos/11%20i2c/oled.lua
The oled1306 can be controled via I2C.

We are sorry, the I2C module has not been well tested at present.

[sn2k]

The oled.lua example uses only output to i2c
But Input I2C is not working.

[Triade1]

Hello, the i2c module works ok.

Read bh1750 lux metter:

local id = 0 -- i2c device ID
local addr = 0x23 -- default i2c address
local init = false
local lux
local i2c = i2c

function init(sda, scl,address)
i2c.setup(id,sda,scl,i2c.SLOW)
if (address ~= nil ) then
addr = address
end
i2c.start(id)
i2c.address(id, addr, 'w')
i2c.write(id, 0x01) --power-on
i2c.stop(id)
i2c.start(id)
i2c.address(id, addr, 'w')
i2c.write(id, 0x10) -- set mode
i2c.stop(id)
tmr.delayms(250) -- delay for 250 msec
init = true
end

local function read_data()
i2c.start(id)
i2c.address(id, addr, 'r')
recv = i2c.read(id, 2) -- read two bytes
i2c.stop(id)
return recv
end

function readBH1750()
if (not init) then
M.init()
end
data = read_data()
lux = (256 * string.byte(data,1) + string.byte(data,2))/1.2
return lux
end

sda_pin = 11
scl_pin = 10
local bh1750_addr = 0x23

init(sda_pin, scl_pin, bh1750_addr)
local value = readBH1750()

if value == nil then
lux = '--.-'
else
lux = string.format("%.1f", value)
end

print(lux)

[Triade1]

Read HTU21 / SHT21 temp / humidity sensor:

local id = 0 -- i2c device ID
local addr = 0x40 -- default i2c address
local init = false
local reg_readtemp = 0xf3 -- Trigger Temperature Measurement, No Hold Master
local reg_readhumid = 0xf5 -- Trigger Humidity Measurement, No Hold Master
local reg_reset = 0xfe
local temperature
local humidity
local i2c = i2c

function init(sda, scl,address)
i2c.setup(id,sda,scl,i2c.SLOW)
i2c.start(id)
i2c.address(id, address,'w')
--i2c.address(id, address, i2c.TRANSMITTER)
i2c.write(id, reg_reset)
i2c.stop(id)
tmr.delayms(150);
init = true
end

local function read_data(reg_addr)
i2c.start(id)
i2c.address(id, htu21d_addr, 'w')
i2c.write(id, reg_addr)
i2c.stop(id)
tmr.delayms(50) -- delay for 50msec
i2c.start(id)
i2c.address(id, htu21d_addr, 'r')
local recv = i2c.read(id, 3) -- read three bytes
--print(string.byte(recv,1))
--print(string.byte(recv,2))
i2c.stop(id)
local value = (256 * string.byte(recv,1)) + bit.band(string.byte(recv,2), 0xfc)
return value
end

function readTemperature()
if (not init) then
M.init()
end
local T = read_data(reg_readtemp)
if T == nil then
return nil
end
return T
end

function readHumidity()
if (not init) then
M.init()
end
local RH = read_data(reg_readhumid)
if RH == nil then
return nil
end
return RH
end

sda_pin = 11
scl_pin = 10
htu21d_addr = 0x40

init(sda_pin, scl_pin, htu21d_addr)

local t = readTemperature()
print(t)
local temp = (-46.85 + (175.72 * t)/65536)
print(temp)

local h = readHumidity()
print(h)
local hum = (-6 + (125.0 * h)/65536)
print(hum)

[sn2k]

I have write the SHT21 in a module, thats work.
But when i want with a timer to get value the mcu reboots.

SDA_PIN = 11 -- sda pin, GPIO2
SCL_PIN = 10 -- scl pin, GPIO0

-- temperature and humidy
local te,hu

sht21 = require("sht21_module")

local function get_data()
sht21.init(SDA_PIN, SCL_PIN)
sht21.read()
te = sht21.getTemperature()
hu = sht21.getHumidy()

-- temperature in degrees Celsius
print("gTemperature: "..te)

-- humidy
print("gHumidy: "..hu)
end

get_data() -- WORK
get_data() -- WORK
get_data() -- WORK

local function tmr_cb()
get_data() -- FAIL >>>>>>>>>>>>>>[
end

tmr.start(0,2000,tmr_cb)

function exit()
-- release module
sht21 = nil
package.loaded["sht21"]=nil
end

Sorry a can't upload the module file

[Triade1]

I have the same issue with timers...

Solution:

function setTimer0()
timer0 = true
end

function setTimer1()
timer1 = true
end

function setTimer2()
timer2 = true
end

-- INIT

timer0 = false
timer1 = false
timer2 = false

tmr.start(0,1000,setTimer0)
tmr.start(1,1000,setTimer1)
tmr.start(2,1000,setTimer2)

while( true )
do
if (timer0) then
timer0 = false
readTemp()
end

if (timer1) then
timer1 = false
readLux()
end

if (timer2) then
timer2 = false
readGas()
end

tmr.delayms(1000)
end

[sn2k]

I2C is still buggy i have trobbels with TSL 2561 2xTSL works with WifiMcu 4x not Working.
But i have the Same tested with NodeMCU all works fine.
I have capture the SCL and SDA Line

Please check the I2C Module

[sn2k]

Project Wifimcu Dead?

[Karim1975]

Hi all,
I have a problem with I2C module. When i send I2C.adress, the function I2C.adress return nil, never 1.
Function: i2c.address(id, dev_addr, 'w') with id=0, dev_adress=slave adress, 'w': want to write.
Morever i see the schem of the WIFIMCU board, and i see that the push pull resistor is 10K in SDL and SCL Line. That's correct value ?
Thanks for your help.