Grove HUB unit trouble

[vvs551]

DHT12 in Environment Sensor unit does not working when it will connected to Grove HUB unit.
BMP280 in the same configuration is working

[m5-docs]

@vvs551
Do you mean that you are programming ENV unit which consists of DHT12 and BMP280? And the connection: ENV unit -> Hub unit -> M5Core. Finally, you can not read DHT12 value but BMP280 works well?

[vvs551]

@watson Absolutely.
I could not scan DHT12 address

[m5-docs]

@vvs551
How about ENV unit connects to M5Core straightly?

[vvs551]

@watson in case of direct connection, ENV unit is working without any problem

[PlayTheGame]

@vvs551 If you wire the ENV module to the GROVE port A (with and without HUB) do you have the charging base connected?
Specifically do you have the M5GO Base (e.g. Fire) or the Core Bottom Base?

[vvs551]

Oh yes!)
I discovered the cause of this problem with ENV unit
It is long cable (50 cm) to HUB unit
When I connected HUB unit with short cable to m5core - all I2C addresses was scanned successfully!

[ajb2k3]

@vvs551 said in Grove HUB unit trouble:

Oh yes!)
I discovered the cause of this problem with ENV unit
It is long cable (50 cm) to HUB unit
When I connected HUB unit with short cable to m5core - all I2C addresses was scanned successfully!

Nice discovery

[vvs551]

Unfortunately, all these wires were bought in the official m5stack store(
Including 50 cm wire

[lukasmaximus]

Are the wires in the same order as your short cables? we were having QC issues for a while where the manufacturing department put the wires in the wrong order into the grove connector. Would greatly appreciate if you could double check for me.

Thanks

[ajb2k3]

Also out of scientific curiosity, try wrapping the wires in some foil. It could be that the larger wire need to be shielded or the device may need its own power at that distance

[lukasmaximus]

I tested a hub device attached to port A with a few 100cm grove cables and I was able to successfully read the i2c address of the ENV sensor and also others. I tested with the i2c_tester arduino program https://github.com/m5stack/M5Stack/blob/master/examples/Advanced/I2C_Tester/I2C_Tester.ino perhaps its just an isolated incident.