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Geekworm RPI Power Pack HAT Lithium Battery with Expansion Board
Overview: This is a power expansion Board especially designed for Raspberry Pi£¬ which enables to use the Raspberry Pi with a moveable power source. It's more convenient to use external 3.7V Lithium battery or 3.7V 18650 Lithium battery; Features: - Supports I2S Output with Capacity & Voltage Reading Function (provide algorithms and examples) - Support Raspberry pi or Android & Apple Phone or Pad or other electronic device charging; - Supports charging while discharging£¬(Very stable£¬ the maximum output current can up to 1.8A while charging£¬ but the chip heat will become larger. maybe you can place a external heatsilk on clip.) - With 4 LED power indicator; - Standard dimension of Raspberry Pi HAT; - Two power supply modes: GPIO power output and USB power out; - Removable battery£¬ The external lithium battery requirements: 3.7V lithium battery; - Built-in power path management£¬ perfect support charging While discharging. - Intelligent 3-stage charging (trickle£¬ constant current£¬ constant voltage)£¬ it can effectively extend the battery life. - Maximum discharge current: 2A£¬ Maximum charge current: 1.8A; - Output protection: overcurrent£¬ short circuit£¬ undervoltage protection; - Input protection: overvoltage£¬ overcharge£¬ undervoltage protection; I2C test of this board (on raspberry pi ): 1. i2cdetect -y 1 #check if there is a I2C device£» 2. i2cdump -y 1 0x62 # (device address) (You can see£º0x0A address register default value is 0xC0) 3. i2cset -y 1 0x62 0x0A 0x00 #Wake-up the device I2C function; MODE register address 0x0A set to 0x00 4. i2cdump -y 1 0x62 #VCELL(cell voltage) address£º0x02 - 0x03 PS: 0x62 is the device address of I2C device£¨power management chip£© How to read the voltage values that saved by chip register? sudo i2cget -y 1 0x62 0x02 w get the value 0xf82f; swap high and low byte to get 0x2ff8; 0x2ff8 converted to decimalism is 12280; 12280 * 305 = 3745400 uV 3745400/1000000 = 3.7454V PS: 305 is a fixed value (Fix factor value); How to read the voltage capacity (percentage) estimated by the chip? # read the integer part of the battery percentage; sudo i2cget -y 1 0x62 0x4 b the resulting value is 0x11; Converted to 10 decimalism is 17£¬ then the remaining capacity is 17%; #Read the fractional part of the battery percentage: sudo i2cget -y 1 0x62 0x5 b the resulting value is 0x95; Converted to decimalism is 149; Then the fractional part is 149/256 = 0.58; So the chip estimated remaining capacity (percentage) is 17.58%.