dht module returns checksum errors/weird values
wilhelmy opened this issue · comments
I recently updated, now I'm getting checksum errors with the dht module.
On the old firmware, I suspect the readings are way off, more than the ±2°C tolerance which are specified for the sensor iirc. Is this normal?
In case it matters, this is a WeMos D1 mini and 3 DHT11 sensors.
Expected behavior
NodeMCU 3.0.0.0
branch: master
commit: 3d91785
release: 3.0-master_20190907 +2
release DTS: 202002231746
SSL: false
build type: float
LFS: 0x0
modules: adc,bit,dht,file,gpio,i2c,mqtt,net,node,ow,spi,tmr,uart,wifi
build 2020-03-17 02:44 powered by Lua 5.1.4 on SDK 3.0.1-dev(fce080e)
lua: cannot open init.lua
for i=5,7 do print(dht.read11(i)) end
0 24 34 0 0
0 25 33 0 0
0 23 38 0 0
Actual behavior
NodeMCU 3.0.0.0
branch: master
commit: 4f67927
release: 3.0-release_20201107
release DTS: 202011071523
SSL: false
build type: float
LFS: 0x0 bytes total capacity
modules: adc,bit,dht,file,gpio,i2c,mqtt,net,node,ow,spi,tmr,uart,wifi
build 2020-11-12 01:20 powered by Lua 5.1.4 on SDK 3.0.1-dev(fce080e)
cannot open init.lua:
for i=5,7 do print(dht.read11(i)) end
0 614.4 870.4 400 400
-1 614.4 896 400 0
-1 742.4 1203.2 400 200
for i=5,7 do print(dht.read11(i)) end
-1 793.6 1203.2 600 200
-1 793.6 1203.2 600 200
-1 793.6 1203.2 600 200
for i=5,7 do print(dht.read11(i)) end
-2 -999 -999 0 0
-2 -999 -999 0 0
-2 -999 -999 0 0
for i=5,7 do print(dht.read11(i)) end
-1 793.6 1203.2 600 200
-1 793.6 1203.2 600 200
-1 793.6 1203.2 600 200
for i=5,7 do print(dht.read11(i)) end
-2 -999 -999 0 0
-2 -999 -999 0 0
-2 -999 -999 0 0
for i=5,7 do print(dht.read11(i)) end
-1 793.6 1203.2 600 200
-1 793.6 1203.2 600 200
-1 793.6 1203.2 600 200
I'm facing the same issue with the latest version of dht module. More details here: #3210 (comment)
Which is the recommended way of building the firmware but using the previous working version of dht module?
Thanks in advance for your wisdom! =)
I confirm the issue is due to #3210. I'll try to fix it in coming days.
Would it be possible to merge this into master?
#3334 will soon be merged - to dev. Once we release it, planned at the end of this month, it'll be available on release and master. See https://github.com/nodemcu/nodemcu-firmware/tree/dev#releases for details.
