![]() ![]() So, if all right, I can drive with max 20mA from Atmega (well below the 40mA max).Īnd so. All right? (From page 2 of datasheet, (IC = 150 mAdc, IB = 15 mAdc) under Collector−Emitter Saturation Voltage. ![]() If I did understand, when I want saturate base the current need to be ~ 1/10 of the collector. I want connect the Ground of booster to the COLLECTOR of transistor and EMITTER to the rail ground, with a PIN moving the base.ġ - First question: is it right to put "ground" from booster to collector and base TO the ground rail of breadboard? So, I thought to cut the ground of the booster with a NPN transistor (PN2222A, datasheet: ) and active from asleep the transistor, read, put outpit pin to low, send data and sleep.īecause the DHT22 only consume 1.5mA when reading (datasheet: ) the PN2222A can supports the 5V from an Atmega PIN and the current beetween C-E. When full charged, battery last only for 1900/2.2 = 863h = ~ 35days. So, I'm using the worst scenario: 2.2mA wasted. So, battery direct to Atmega and Radio NRF24L01, both to 2.74 (and less) and fixed voltage at 3.3V for the DHT22.Īll works in a breadboard, but I don't understand what's the quiescent current of MT3608 (here the datasheet: ), cause data report different PFM and PWM. The DHT22 min voltage is 3.3V, so I did buy this: and regulated exit to 3.3v. I did read a DHT22 and send every 10 min data to a gateway (MySensors installation), all other time the Atmega sleeps. I feed it with 2XAA in series (~ 2.74volt when full charged and 1900mah). I did bootload an Atmega with BOD disabled. ![]()
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