EESchema Schematic File Version 4
EELAYER 30 0
EELAYER END
$Descr A4 11693 8268
encoding utf-8
Sheet 1 1
Title ""
Date ""
Rev ""
Comp ""
Comment1 ""
Comment2 ""
Comment3 ""
Comment4 ""
$EndDescr
$Comp
L RF:NRF24L01_Breakout U?
U 1 1 5E580EDF
P 9250 2700
F 0 "U?" H 9630 2746 50  0000 L CNN
F 1 "NRF24L01_Breakout" H 9630 2655 50  0000 L CNN
F 2 "RF_Module:nRF24L01_Breakout" H 9400 3300 50  0001 L CIN
F 3 "http://www.nordicsemi.com/eng/content/download/2730/34105/file/nRF24L01_Product_Specification_v2_0.pdf" H 9250 2600 50  0001 C CNN
	1    9250 2700
	1    0    0    -1  
$EndComp
$Comp
L Sensor:BME280 U?
U 1 1 5E581272
P 9200 4750
F 0 "U?" H 8770 4704 50  0000 R CNN
F 1 "BME280" H 8770 4795 50  0000 R CNN
F 2 "Package_LGA:Bosch_LGA-8_2.5x2.5mm_P0.65mm_ClockwisePinNumbering" H 10700 4300 50  0001 C CNN
F 3 "https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BME280-DS002.pdf" H 9200 4550 50  0001 C CNN
	1    9200 4750
	1    0    0    -1  
$EndComp
$Comp
L power:GND #PWR?
U 1 1 5E5840E4
P 9100 5500
F 0 "#PWR?" H 9100 5250 50  0001 C CNN
F 1 "GND" H 9105 5327 50  0000 C CNN
F 2 "" H 9100 5500 50  0001 C CNN
F 3 "" H 9100 5500 50  0001 C CNN
	1    9100 5500
	1    0    0    -1  
$EndComp
Wire Wire Line
	9100 5350 9100 5400
Wire Wire Line
	9300 5350 9300 5400
Wire Wire Line
	9300 5400 9100 5400
Connection ~ 9100 5400
Wire Wire Line
	9100 5400 9100 5500
$Comp
L Device:C C?
U 1 1 5E5847B0
P 8450 4200
F 0 "C?" H 8565 4246 50  0000 L CNN
F 1 "100 nF" H 8565 4155 50  0000 L CNN
F 2 "" H 8488 4050 50  0001 C CNN
F 3 "~" H 8450 4200 50  0001 C CNN
	1    8450 4200
	1    0    0    -1  
$EndComp
Wire Wire Line
	9100 4050 9100 4150
Wire Wire Line
	9300 4150 9300 4050
Wire Wire Line
	9300 4050 9100 4050
$Comp
L power:GND #PWR?
U 1 1 5E584F8B
P 8450 4450
F 0 "#PWR?" H 8450 4200 50  0001 C CNN
F 1 "GND" H 8455 4277 50  0000 C CNN
F 2 "" H 8450 4450 50  0001 C CNN
F 3 "" H 8450 4450 50  0001 C CNN
	1    8450 4450
	1    0    0    -1  
$EndComp
Wire Wire Line
	8450 4450 8450 4350
Wire Wire Line
	9100 4050 8450 4050
Connection ~ 9100 4050
$Comp
L power:VCC #PWR?
U 1 1 5E587A3C
P 9100 3950
F 0 "#PWR?" H 9100 3800 50  0001 C CNN
F 1 "VCC" H 9117 4123 50  0000 C CNN
F 2 "" H 9100 3950 50  0001 C CNN
F 3 "" H 9100 3950 50  0001 C CNN
	1    9100 3950
	1    0    0    -1  
$EndComp
Wire Wire Line
	9100 3950 9100 4050
$Comp
L Device:C C?
U 1 1 5E588ABC
P 9900 2200
F 0 "C?" H 10015 2246 50  0000 L CNN
F 1 "C" H 10015 2155 50  0000 L CNN
F 2 "" H 9938 2050 50  0001 C CNN
F 3 "~" H 9900 2200 50  0001 C CNN
	1    9900 2200
	1    0    0    -1  
$EndComp
$Comp
L power:GND #PWR?
U 1 1 5E588AC2
P 9900 2450
F 0 "#PWR?" H 9900 2200 50  0001 C CNN
F 1 "GND" H 9905 2277 50  0000 C CNN
F 2 "" H 9900 2450 50  0001 C CNN
F 3 "" H 9900 2450 50  0001 C CNN
	1    9900 2450
	1    0    0    -1  
$EndComp
Wire Wire Line
	9900 2450 9900 2350
Wire Wire Line
	9250 2050 9900 2050
$Comp
L power:VCC #PWR?
U 1 1 5E58967F
P 9250 1950
F 0 "#PWR?" H 9250 1800 50  0001 C CNN
F 1 "VCC" H 9267 2123 50  0000 C CNN
F 2 "" H 9250 1950 50  0001 C CNN
F 3 "" H 9250 1950 50  0001 C CNN
	1    9250 1950
	1    0    0    -1  
$EndComp
Wire Wire Line
	9250 1950 9250 2050
Wire Wire Line
	9250 2050 9250 2100
Connection ~ 9250 2050
Text GLabel 8650 2500 0    50   Input ~ 0
MISO
Text GLabel 8650 2600 0    50   Input ~ 0
SCK
Text GLabel 8650 2700 0    50   Input ~ 0
NRF24_CS
Wire Wire Line
	8650 2400 8750 2400
Wire Wire Line
	8750 2500 8650 2500
Wire Wire Line
	8650 2600 8750 2600
Wire Wire Line
	8750 2700 8650 2700
Wire Wire Line
	9900 4450 9800 4450
Wire Wire Line
	9800 4650 9900 4650
Wire Wire Line
	9900 4850 9800 4850
Wire Wire Line
	9800 5050 9900 5050
$Comp
L power:GND #PWR?
U 1 1 5E5919B1
P 4800 4000
F 0 "#PWR?" H 4800 3750 50  0001 C CNN
F 1 "GND" H 4805 3827 50  0000 C CNN
F 2 "" H 4800 4000 50  0001 C CNN
F 3 "" H 4800 4000 50  0001 C CNN
	1    4800 4000
	1    0    0    -1  
$EndComp
$Comp
L power:GND #PWR?
U 1 1 5E595499
P 9250 3400
F 0 "#PWR?" H 9250 3150 50  0001 C CNN
F 1 "GND" H 9255 3227 50  0000 C CNN
F 2 "" H 9250 3400 50  0001 C CNN
F 3 "" H 9250 3400 50  0001 C CNN
	1    9250 3400
	1    0    0    -1  
$EndComp
Wire Wire Line
	9250 3300 9250 3400
Text GLabel 5950 1700 2    50   Input ~ 0
MISO
Text GLabel 5950 1600 2    50   Input ~ 0
MOSI
Text GLabel 5950 1800 2    50   Input ~ 0
SCK
Text GLabel 6250 3550 2    50   Input ~ 0
NRF24_CS
Text GLabel 6250 3450 2    50   Input ~ 0
BME280_CS
NoConn ~ 8750 3000
Text GLabel 6250 3350 2    50   Input ~ 0
CE
Text GLabel 8650 2900 0    50   Input ~ 0
CE
Wire Wire Line
	8650 2900 8750 2900
$Comp
L Device:C C?
U 1 1 5E5A4C2E
P 7900 4200
F 0 "C?" H 8015 4246 50  0000 L CNN
F 1 "100 nF" H 8015 4155 50  0000 L CNN
F 2 "" H 7938 4050 50  0001 C CNN
F 3 "~" H 7900 4200 50  0001 C CNN
	1    7900 4200
	1    0    0    -1  
$EndComp
$Comp
L power:GND #PWR?
U 1 1 5E5A4C34
P 7900 4450
F 0 "#PWR?" H 7900 4200 50  0001 C CNN
F 1 "GND" H 7905 4277 50  0000 C CNN
F 2 "" H 7900 4450 50  0001 C CNN
F 3 "" H 7900 4450 50  0001 C CNN
	1    7900 4450
	1    0    0    -1  
$EndComp
Wire Wire Line
	7900 4450 7900 4350
Wire Wire Line
	8450 4050 7900 4050
Connection ~ 8450 4050
Text GLabel 8650 2400 0    50   Input ~ 0
MOSI
Text GLabel 9900 4650 2    50   Input ~ 0
SCK
Text GLabel 9900 4450 2    50   Input ~ 0
MISO
Text GLabel 9900 4850 2    50   Input ~ 0
MOSI
Text GLabel 9900 5050 2    50   Input ~ 0
BME280_CS
$Comp
L Power_Supervisor:TPS3839DBZ U?
U 1 1 5E5B3B08
P 2150 6800
F 0 "U?" H 2020 6846 50  0000 R CNN
F 1 "TPS3839L30DBZR" H 2020 6755 50  0000 R CNN
F 2 "Package_TO_SOT_SMD:SOT-23" H 2150 6800 50  0001 C CNN
F 3 "http://www.ti.com/lit/ds/sbvs193d/sbvs193d.pdf" H 2150 6800 50  0001 C CNN
	1    2150 6800
	1    0    0    -1  
$EndComp
$Comp
L Device:D_Zener D?
U 1 1 5E5B4A6A
P 2750 7050
F 0 "D?" V 2704 7129 50  0000 L CNN
F 1 "ESD3Z12" V 2795 7129 50  0000 L CNN
F 2 "" H 2750 7050 50  0001 C CNN
F 3 "~" H 2750 7050 50  0001 C CNN
	1    2750 7050
	0    1    1    0   
$EndComp
Wire Wire Line
	2950 6800 2750 6800
Wire Wire Line
	2750 6800 2750 6900
Connection ~ 2750 6800
Wire Wire Line
	2750 6800 2550 6800
$Comp
L Device:Battery_Cell BT?
U 1 1 5E5BF5B4
P 700 6450
F 0 "BT?" H 818 6546 50  0000 L CNN
F 1 "AAA battery" H 818 6455 50  0000 L CNN
F 2 "" V 700 6510 50  0001 C CNN
F 3 "~" V 700 6510 50  0001 C CNN
	1    700  6450
	1    0    0    -1  
$EndComp
$Comp
L Device:Battery_Cell BT?
U 1 1 5E5C0221
P 700 6850
F 0 "BT?" H 818 6946 50  0000 L CNN
F 1 "AAA battery" H 818 6855 50  0000 L CNN
F 2 "" V 700 6910 50  0001 C CNN
F 3 "~" V 700 6910 50  0001 C CNN
	1    700  6850
	1    0    0    -1  
$EndComp
Wire Wire Line
	700  6650 700  6550
Wire Wire Line
	700  6250 700  6150
Wire Wire Line
	700  6150 2150 6150
Wire Wire Line
	2150 6150 2150 6500
Wire Wire Line
	700  7450 2150 7450
Wire Wire Line
	2150 7450 2150 7100
Wire Wire Line
	2150 7450 2750 7450
Wire Wire Line
	2750 7450 2750 7200
Connection ~ 2150 7450
Wire Wire Line
	2750 7450 3250 7450
Wire Wire Line
	3250 7450 3250 7000
Connection ~ 2750 7450
$Comp
L Regulator_Linear:MCP1700-3302E_SOT89 U?
U 1 1 5E5C950E
P 4850 6150
F 0 "U?" H 4850 6392 50  0000 C CNN
F 1 "MCP1700-3302E_SOT89" H 4850 6301 50  0000 C CNN
F 2 "Package_TO_SOT_SMD:SOT-89-3" H 4850 6350 50  0001 C CNN
F 3 "http://ww1.microchip.com/downloads/en/DeviceDoc/20001826D.pdf" H 4850 6100 50  0001 C CNN
	1    4850 6150
	1    0    0    -1  
$EndComp
Wire Wire Line
	2150 6150 4300 6150
Connection ~ 2150 6150
$Comp
L Device:C C?
U 1 1 5E5CCED6
P 4300 6400
F 0 "C?" H 4415 6446 50  0000 L CNN
F 1 "10uF" H 4415 6355 50  0000 L CNN
F 2 "" H 4338 6250 50  0001 C CNN
F 3 "~" H 4300 6400 50  0001 C CNN
	1    4300 6400
	1    0    0    -1  
$EndComp
Wire Wire Line
	4300 6250 4300 6150
Connection ~ 4300 6150
Wire Wire Line
	4300 6150 4550 6150
$Comp
L Device:C C?
U 1 1 5E5D6526
P 5350 6400
F 0 "C?" H 5465 6446 50  0000 L CNN
F 1 "10uF" H 5465 6355 50  0000 L CNN
F 2 "" H 5388 6250 50  0001 C CNN
F 3 "~" H 5350 6400 50  0001 C CNN
	1    5350 6400
	1    0    0    -1  
$EndComp
Wire Wire Line
	5350 6250 5350 6150
Wire Wire Line
	5350 6150 5150 6150
Wire Wire Line
	3250 6600 3250 6500
Wire Wire Line
	3250 6500 4000 6500
Wire Wire Line
	4000 6500 4000 6650
Wire Wire Line
	4000 6650 4300 6650
Wire Wire Line
	5350 6650 5350 6550
Wire Wire Line
	4300 6550 4300 6650
Connection ~ 4300 6650
Wire Wire Line
	4300 6650 5350 6650
$Comp
L power:VCC #PWR?
U 1 1 5E5DC9B3
P 5900 6150
F 0 "#PWR?" H 5900 6000 50  0001 C CNN
F 1 "VCC" H 5917 6323 50  0000 C CNN
F 2 "" H 5900 6150 50  0001 C CNN
F 3 "" H 5900 6150 50  0001 C CNN
	1    5900 6150
	1    0    0    -1  
$EndComp
$Comp
L power:GND #PWR?
U 1 1 5E5DD008
P 5900 6650
F 0 "#PWR?" H 5900 6400 50  0001 C CNN
F 1 "GND" H 5905 6477 50  0000 C CNN
F 2 "" H 5900 6650 50  0001 C CNN
F 3 "" H 5900 6650 50  0001 C CNN
	1    5900 6650
	1    0    0    -1  
$EndComp
Wire Wire Line
	5900 6650 5350 6650
Connection ~ 5350 6650
Wire Wire Line
	5350 6150 5900 6150
Connection ~ 5350 6150
Wire Notes Line
	550  6050 3900 6050
Wire Notes Line
	3900 6050 3900 7700
Wire Notes Line
	3900 7700 550  7700
Wire Notes Line
	550  7700 550  6050
Text Notes 2900 7650 0    50   ~ 0
disconnect battery when\nvoltage drops below 2V
Wire Wire Line
	700  6950 700  7450
Text Notes 2150 6400 0    50   ~ 0
TODO: different TPS3839
$Comp
L Device:Q_NMOS_GSD Q?
U 1 1 5E5B7982
P 3150 6800
F 0 "Q?" H 3354 6846 50  0000 L CNN
F 1 "BSS138" H 3354 6755 50  0000 L CNN
F 2 "" H 3350 6900 50  0001 C CNN
F 3 "~" H 3150 6800 50  0001 C CNN
	1    3150 6800
	1    0    0    -1  
$EndComp
Wire Notes Line
	4100 5600 4100 7150
Wire Notes Line
	4100 7150 6050 7150
Text Notes 4150 7050 0    50   ~ 0
TODO: not needed if only two batteries are used
Text Notes 800  4400 0    50   ~ 0
Simulated power supply to get the minimum voltage\nof 2 V for testing on a breadboard:
$Comp
L Regulator_Linear:LM317L_TO92 U?
U 1 1 5E750201
P 1550 4750
F 0 "U?" H 1550 4992 50  0000 C CNN
F 1 "LM317T-DG" H 1550 4901 50  0000 C CNN
F 2 "Package_TO_SOT_THT:TO-92_Inline" H 1550 4975 50  0001 C CIN
F 3 "http://www.ti.com/lit/ds/snvs775k/snvs775k.pdf" H 1550 4750 50  0001 C CNN
	1    1550 4750
	1    0    0    -1  
$EndComp
$Comp
L power:+5V #PWR?
U 1 1 5E751705
P 850 4750
F 0 "#PWR?" H 850 4600 50  0001 C CNN
F 1 "+5V" H 865 4923 50  0000 C CNN
F 2 "" H 850 4750 50  0001 C CNN
F 3 "" H 850 4750 50  0001 C CNN
	1    850  4750
	1    0    0    -1  
$EndComp
Wire Wire Line
	850  4750 1250 4750
$Comp
L Device:R R?
U 1 1 5E757434
P 2050 4900
F 0 "R?" H 2120 4946 50  0000 L CNN
F 1 "240" H 2120 4855 50  0000 L CNN
F 2 "" V 1980 4900 50  0001 C CNN
F 3 "~" H 2050 4900 50  0001 C CNN
	1    2050 4900
	1    0    0    -1  
$EndComp
Wire Wire Line
	2050 5150 2050 5100
Wire Wire Line
	2050 5100 1550 5100
Wire Wire Line
	1550 5100 1550 5050
Connection ~ 2050 5100
Wire Wire Line
	2050 5100 2050 5050
Wire Wire Line
	2050 4750 1850 4750
$Comp
L power:VCC #PWR?
U 1 1 5E75FB56
P 2250 4750
F 0 "#PWR?" H 2250 4600 50  0001 C CNN
F 1 "VCC" H 2267 4923 50  0000 C CNN
F 2 "" H 2250 4750 50  0001 C CNN
F 3 "" H 2250 4750 50  0001 C CNN
	1    2250 4750
	1    0    0    -1  
$EndComp
Wire Wire Line
	2250 4750 2050 4750
Connection ~ 2050 4750
$Comp
L Device:R R?
U 1 1 5E757A10
P 2050 5300
F 0 "R?" H 2120 5346 50  0000 L CNN
F 1 "144" H 2120 5255 50  0000 L CNN
F 2 "" V 1980 5300 50  0001 C CNN
F 3 "~" H 2050 5300 50  0001 C CNN
	1    2050 5300
	1    0    0    -1  
$EndComp
$Comp
L power:GND #PWR?
U 1 1 5E765082
P 2050 5550
F 0 "#PWR?" H 2050 5300 50  0001 C CNN
F 1 "GND" H 2055 5377 50  0000 C CNN
F 2 "" H 2050 5550 50  0001 C CNN
F 3 "" H 2050 5550 50  0001 C CNN
	1    2050 5550
	1    0    0    -1  
$EndComp
Wire Wire Line
	2050 5450 2050 5550
Wire Notes Line
	650  4150 650  5900
Wire Notes Line
	650  5900 3350 5900
Wire Notes Line
	3350 5900 3350 4150
Wire Notes Line
	3350 4150 650  4150
$Comp
L power:GND #PWR?
U 1 1 5E83B925
P 4850 6450
F 0 "#PWR?" H 4850 6200 50  0001 C CNN
F 1 "GND" H 4855 6277 50  0000 C CNN
F 2 "" H 4850 6450 50  0001 C CNN
F 3 "" H 4850 6450 50  0001 C CNN
	1    4850 6450
	1    0    0    -1  
$EndComp
$Comp
L MCU_Microchip_ATmega:ATmega48PA-AU U?
U 1 1 5E857B8D
P 5250 2500
F 0 "U?" H 5250 911 50  0000 C CNN
F 1 "ATmega48PA-AU" H 5250 820 50  0000 C CNN
F 2 "Package_QFP:TQFP-32_7x7mm_P0.8mm" H 5250 2500 50  0001 C CIN
F 3 "http://ww1.microchip.com/downloads/en/DeviceDoc/ATmega48PA_88PA_168PA-Data-Sheet-40002011A.pdf" H 5250 2500 50  0001 C CNN
	1    5250 2500
	1    0    0    -1  
$EndComp
Wire Wire Line
	4800 4000 5250 4000
$Comp
L Device:C C?
U 1 1 5E888344
P 4350 900
F 0 "C?" H 4465 946 50  0000 L CNN
F 1 "100n" H 4465 855 50  0000 L CNN
F 2 "" H 4388 750 50  0001 C CNN
F 3 "~" H 4350 900 50  0001 C CNN
	1    4350 900 
	1    0    0    -1  
$EndComp
Wire Wire Line
	4350 700  5250 700 
$Comp
L power:GND #PWR?
U 1 1 5E88834B
P 4350 1100
F 0 "#PWR?" H 4350 850 50  0001 C CNN
F 1 "GND" H 4355 927 50  0000 C CNN
F 2 "" H 4350 1100 50  0001 C CNN
F 3 "" H 4350 1100 50  0001 C CNN
	1    4350 1100
	1    0    0    -1  
$EndComp
Wire Wire Line
	4350 1100 4350 1050
Wire Wire Line
	5350 700  5350 1000
Wire Wire Line
	5250 700  5250 1000
Connection ~ 5250 700 
Wire Wire Line
	5250 700  5350 700 
Wire Wire Line
	4350 700  4350 750 
Wire Wire Line
	5950 1600 5850 1600
Wire Wire Line
	5950 1700 5850 1700
Wire Wire Line
	5950 1800 5850 1800
Wire Notes Line
	6050 7150 6050 5600
Wire Notes Line
	6050 5600 4100 5600
$EndSCHEMATC