Hi again 
I have placed a Grove light sensor, and a Grove Temp/Hum sensor in the jar, together with the Grove Shield. All works fine, when connected via USB. But as soon as it is battery powered, the Temp/Hum sensor is not giving any output…
Can anyone explain that??
Elaborate more…
I’ve not used the Grove stuff, but, briefly looking over them, neither the shield or the sensors have a battery input and the shield’s wiki specifies its operation at 5v… So, how do you have the battery connected? What voltage is the battery? What voltage are you getting across the humidity sensor’s power pins? What Arduino board are you using?
I am using: http://www.seeedstudio.com/wiki/Arch_GPRS where there is a battery attached, I havent been able to find the voltage on the battery, but I suspect you to be right. Will measure it tomorrow.
Sounds strange if it is not possible to attach a sensor to the Arch GPRS as this is what it is meant to do…`?
Hmm, just checked that battery - its 3.7 volts.
Bugger, can anyone confirm that sucks! The DHT11 sensors does not work on the Arch GPRS !!!
Hi,
Are you using a base shield? If it is, the issue will be that Grove’s VCC of base shield is 5V but 5V is not available with battery powered.
Are there any way to connect the Grove temp sensor to the Arch GPRS so that it works when the device is battery powered?
Use Arch GPRS’s on-board Grove interfaces
or
breakout the VCC of Grove - Temp/hum sensor and connect it to 3.3V. Grove - Temp/hum sensor is 3.3V and 5V compatible.
Great news! Thanks!
Any news on a stable driver, the existing one is unstable and giving bad readings most of the time…some checksum errors that I have not been able to solve.
Just tried the on board Grove interfaces which seems not to work with the TempHum sensor.
It works when connected to D5 / P1_24 on the base shield. But when connected to the Grove connector on board ADC / P0_12 it does not work.
I think there is an issue with power?