From 276856de6c63bbbf3e56cc08dcca00ba10080b7e Mon Sep 17 00:00:00 2001 From: Sadeep Madurange Date: Sun, 7 Sep 2025 17:04:34 +0800 Subject: Door lock with MOSFETs and and without RFM. --- door_lock/README.txt | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 door_lock/README.txt (limited to 'door_lock/README.txt') diff --git a/door_lock/README.txt b/door_lock/README.txt new file mode 100644 index 0000000..08f320f --- /dev/null +++ b/door_lock/README.txt @@ -0,0 +1,48 @@ +CURRENT MEASUREMENTS + +PERIPHERALS: + +R503 FPM: + +When VCC is connected to a 3.31V supply, FPM draws 13.8mA of quiescent current. When +VCC is disconnected (3.3VT connected to 3.31V supply), it draws 2.9uA. + +FS5106B high-torque servo: + +One of them draws 6.1mA when connected and stabilizes at 4.6mA. The other drew +variable amounts initially (4.7mA, 5mA+, but mostly 4.7). Both draw 4.6mA of +quiescent current with a 5.07V supply. + +TARGET CURRENT DRAW + + 1. 2.7mA for 1 month + 2. 1.4mA for 2 months + 3. 900uA for 3 months + 3. 694uA for 4 months + +LINEAR REGULATORS + + 1. When the ATmega328P is in normal mode, the MCU + FPM + Servo + linear + regulators draw 30.6mA of quiescent current at 5.07V. + 2. When the ATmega328P is in power down mode, the MCU + FPM + Servo + linear + regulators draw 26.2mA of quiescent current at 5.07V. + 3. When the ATmega328P is in power down mode, the MCU + linear regulators draw + 13.7mA of quiescent current at 5.07V (without MOSFETS). + +MP1584EN BUCK CONVERTER + + 1. When the system is in power down mode, the MCU + FPM + Servo draw 8.9mA at + 3.3V. The real amount is likely about 8.9 + 4.6 = 13.5mA. + 2. When FETs are used quiescent current drops to 0uA. + 3. Active current draw (when the servo rotates) measured are 152.8mA, 162.8mA, + 170.3mA + +REMARKS + + 1. Can't use 3.3V FPM modules with Arduino Uno. The RX and TX lines have + resistors. + 2. When measuring current with the buck chips on, the servo doesn't respond. + So, the value measured probably doesn't include the current the servo + draws. + 3. N-channel high-side switching doesn't work without a 9V supply. 7.2V+ with + batteries don't work either. -- cgit v1.2.3