Microduino-BM

Language	English

文件:Microduino-BM-rect.jpg Microduino-BM Microduino-BM is a discharging module which combines a single-cell Li-ion battery charge management, power detection and LED indication. The output voltage is 5V, and LDO is 3.3V output, providing the outstanding battery management for the Microduino-Core module.
Features Support UPS; Integrate lithium battery charge/discharge management, power detection, 5v output, 3.3v LDO; Small, cheap, stackable, open; Uniform Microduino interface standard and rich peripheral modules, capable of having a fast and flexible connection and extension with other modules and sensors in accord with Microduino interface standard;. 2.54-pitch row female connector for easy integration into pegboards.
Specifications Interface A two-notch toggle switch to control the output voltage (5v and 3.3v); A MicroUSB interface for power charging. A 1.27-pitch battery interface; UPIN27 contains the 5V, 3V3 and GND interface; (The analog voltage detection of BM can be selected between A6 and A7, and the digital low voltage will be output to D2 interface. Please don’t rely protection circuit to protect the battery, which only works in extreme circumstance. You can use mcu to detect the voltage of the battery and then judge the battery’s charge. )
Charging Plug in MicroUSB and charge the lithium battery with the current of 600ma. The indicator goes on when charging and goes out after finishing.
Discharging When you plug in MicroUSB, the 5v or 3.3v voltage is powered through MicroUSB. Otherwise, the voltage will be supplied by the lithium battery. Meantime, you need to pull the power output switch to “ON”. If it is not started, please plug in MicroUSB to activate and then try again. The indicator goes on when there is electricity output, otherwise, it goes out. 5V offers 1a electricity output and 3.3V offers 700ma output.
Low-voltage Battery Protection	class="wikitable"
Undervoltage indication	3.60V
Low-voltage protection	2.40V
Indicator-off voltage when the voltage gets back.	3.71V

Low voltage indicator goes on under 3.60V and when the voltage keeps decreasing to 2.40V, the lithium battery protection circuit works. The indicator will go out when the battery is powered to 3.71V.

Short-circuit Protection

When the output current reaches 1.2A, the lithium battery protection circuit starts and cuts off power supply. The circuit will be activated and get back to work only when you plug in MicroUSB to charge.

Efficiency of BM and Its Load Driven Capacity

100ma 5.05v output:

文件:Micrmodule-BM-100.jpg

100ma/5.05V

|- | 300ma 5.05v output:

文件:Micrmodule-BM-300.jpg

300ma/5.05V

|- | 500ma 5.05v output:

文件:Micrmodule-BM-500.jpg

500ma/5.05V

|- | 700ma 5.05v output:

文件:Micrmodule-BM-700.jpg

700ma/5.05V

|- | 1A 5.05v output:

文件:Micrmodule-BM-1A.jpg

1A/5.05V

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文件:Micrmodule-BM-Analysis.jpg

image

|- | We can see from data above that BM’s 5v output shows excellent transfer efficiency no matter under low or high power output. The load driven capacity of that can reach 1A. The 3.3v transferring efficiency depends on the 1117 chip, which should be around 60% and the load driven capacity can reach up to 600ma.

Temperature Rise of System Operation

Temperature rise under 5v output and 30 ℃ indoor:

文件:Micrmodule-BM-temp-30.jpg

600px

|- | Temperature rise under 3.3v output and 26 ℃ indoor:

文件:Micrmodule-BM-temp-26.jpg

600px

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Documents

• Microduino-BM Eagle source file 【download】
• Microduino-BM main chips and devices

Main components

• Chip 1: HT4901 HT4901 Application guidelines Media: HT4901 Application guidelines V1.1.pdf
• Chip 2: LP2985AIM5X-3.3 Media:LP2985.pdf
• MOSFET: AO3400 Media:AO3400.pdf
• Schottky diodes: MBR0520 Media:MBR0520.pdf
• Toggle switch: MSK-12C01 (1P2T) Media:MSK-12C01(1P2T).pdf.

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Development

• Battery: single-cell 3.7v li-ion battery;
• Recommended battery module is connected with 2PIN DuPont;
• Recommended power options: voltage 5V, current 600ma above, such as: computer USB, 5V phone charger.

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Applications

When viewing the board with the battery connector and switches closest to you, with the component side up, the battery connector positive (+) pin is on the left and the ground (-) pin is on the right. The pushbutton switch is on the left and the mode switch (IN = Charge, lever to the left; OUT = Discharge, lever to the right) is on the right.

After connecting the battery you must momentarily push the pushbutton switch to start the converter. You can stop the converter/turn off the power by unplugging the battery or by pressing and holding the pushbutton for a few seconds. To use the battery to generate +5 VDC and +3.3 VDC, set the mode switch (to the right of the battery connector when viewed as described above) to OUT (switch lever away from the battery connector). The IN position is used for charging the battery from an external 5VDC, >=600 mA source.

The charging current is 500 mA, so I recommend a battery with at least 500 mAH of capacity to avoid charging at a rate >1C.

A rough English translation of the charging process is as follows:

• Set the mode switch to OUT (switch lever away from the battery connector);
• Plug in the battery;
• Plug in the external 5VDC power supply (at least a 600 mA supply recommended);
• Set the mode switch to IN (switch lever toward the battery connector);
• When charging is complete as indicated by all 4 LEDs on, set the mode switch to OUT (switch lever away from the battery connector);
• Unplug the external 5VDC power supply.

The LED indications seem to be as follows, based on how Google Translate translates the Chinese datasheet for the HOTCHIP HT4901 at http://www.hotchip.com.cn/DownFiles/20131126090806453.pdf

Discharge Mode

Voltage	LED1	LED2	LED3	LED4
3.2-3.5V	ON	OFF	OFF	OFF
3.5-3.65V	ON	ON	OFF	OFF
3.65-3.95V	ON	ON	ON	OFF
> 3.95V	ON	ON	ON	ON

If the voltage drops below 3.2V, LED1 flashes and within 5 seconds the HT4901 goes to standby mode (I think... or should I say I hope...) to avoid over-discharging your battery.

Charge Mode

Voltage	LED1	LED2	LED3	LED4
<3.4V	FLASH	FLASH	FLASH	FLASH
3.4-3.8V	ON	FLASH	FLASH	FLASH
3.8-4.0V	ON	ON	FLASH	FLASH
4.0-4.25V	ON	ON	ON	FLASH
>= 4.25V	ON	ON	ON	ON

Be prepared to terminate the charging process immediately when all four LEDs are on and steady. Overcharging lithium-type batteries may result in a nasty fire. I don't know how good the HT4901 is at detecting that the charging process is complete and shutting off the charging current to the battery.

Hope I correctly translated this information.

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Pictures

文件:Micrmodule-BM-t.jpg

Micrmodule BM Front

文件:Micrmodule-BM-b.jpg

Micrmodule BM Back

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FQA

• Does this module can power on other Microduino modules?
  • Yes, most modules can be power by this module, except the big power module, such as GPRS module.
• Does the BM module and USB module can work together to power on Microduino module?
  • Don't suggest use them like this, but our new BM version will support UPS.
• Does this module is programmable and set its state by software?
  • No, it isn't programmable.
• What the max range of voltage and current?
  • 5V/500mA。
• Does this module can charge Li-ion battery?
  • Yes.
• Do you have a module that can install a Li-ion battery?
  • No.
• Does the Microduino module can use old mobile phone Li-ion battery.
  • Yes.

History

November 14, 2013 new release, major improvements:

• Canceled VMOT pin, use the toggle switch directly and use the 5V port switching charge and discharge;
• Boost pushbutton can fully control the boost, UPIN27 the GND loop off.
• March 13, 2013 Batch completed.
• March 1, 2013 20130202 edition model released, testing is no big problem.
• February 2, 2013, using mobile power ASIC chip, re-layout.
• December 31, 2012, released the test panels, the main problems are:
• No 5V output;
• Battery Interface leakage;
• No power display.

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