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This [[phil_crump:boards:avr_sensor_v3|AVR Sensor Board V3]] node has all components and headers installed and has a DHT22 as the sensor. The antenna is a 1/4 wave wire.

It is running from 3 AA NiMH cells installed in a battery holder salvaged from a time expired CO detector. The battery voltage reading appears to not suffer from thermal error despite having 4M7 and 1M resistors in the ADC divider.

2015-01-20 15:45 - Having spent some time sitting on the workbench in the utility room it was placed inside a plastic drink bottle with the bottom cut off and moved out to a sheltered corner of the garden under a tree.

{{:dbrooke_nodes:p1010889.jpg?direct&200|}} {{:dbrooke_nodes:p1010887.jpg?direct&100|}} {{:dbrooke_nodes:p1010888.jpg?direct&200|}}

2015-03-24 - Since the move to an outdoor location it has become apparent that the battery voltage does suffer from error under conditions of low temperature combined with high humidity.

2015-07-23 18:30 - Resistors in the battery voltage ADC divider changed to 470k and 100k and the batteries recharged.

2017-09-22 - The AVR shut down due to flat batteries but the RFM69 continued to transmit for 6 hours as can be seen by the raised threshold in [[https://grafana.ukhas.net/dashboard/db/db?panelId=10&fullscreen&from=1506027600000&to=1506070800000|this graph]].

2017-09-29 - This hardware has now been re-deployed in the bathroom as DB07

2017-10-03 - Now using new hardware and housed in a box like [[dbrooke_nodes:dbd1|DBD1]]. It is located at the other side of the garden where it should be shaded from the summer evening sun which had been causing higher than actual temperature readings.
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