Battery pack LED display circuit

Abstract

The embodiment of the utility model discloses a battery pack LED display circuit which comprises a single-chip microcomputer chip, a current-limiting resistor, a first LED lamp bead and a second LED lamp bead, and one IO pin of the single-chip microcomputer chip is connected with the negative electrode of the first LED lamp bead and the positive electrode of the second LED lamp bead through the current-limiting resistor. The positive electrode of the first LED lamp bead and the negative electrode of the second LED lamp bead are connected with a VDD pin and a GND pin of the single-chip microcomputer chip respectively. According to the utility model, the structure is simple, only one IO pin and one current-limiting resistor are needed to control the two LED lamp beads to realize four states, the size is greatly reduced, and the hardware cost is saved.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery tools, and in particular to a battery pack LED display circuit. Background Technology

[0002] Most existing battery packs use microcontroller chips to control two LEDs to indicate their operating status. Even when using microcontroller chip input / output pins (hereinafter referred to as I / O pins) to control LEDs, existing PD battery packs typically use one I / O pin of the microcontroller chip to light up one LED (e.g., ...). Figure 1 and Figure 2 (As shown) or a scanning method that uses multiple I / O pins of a microcontroller chip to light up multiple LEDs (such as...) Figure 3 (As shown).

[0003] In current technology, a single LED typically occupies one or even multiple I / O pins on a microcontroller chip. The principle is that the microcontroller chip's I / O port outputs a high or low level, creating a corresponding potential difference across the LED. A resistor limits the current, allowing the LED to reach saturation. Each pin illuminating an LED is connected in series with a current-limiting resistor. As a product uses more LEDs, the number of current-limiting resistors increases, leading to more circuit board components and higher costs. Increased trace count also increases the required circuit board space. Utility Model Content

[0004] The technical problem to be solved by this utility model embodiment is to provide a battery pack LED display circuit to reduce costs.

[0005] To solve the above-mentioned technical problems, this utility model embodiment proposes a battery pack LED display circuit, including a microcontroller chip, a current-limiting resistor, a first LED bead, and a second LED bead. One of the IO pins of the microcontroller chip is connected to the negative terminal of the first LED bead and the positive terminal of the second LED bead through the current-limiting resistor. The positive terminal of the first LED bead and the negative terminal of the second LED bead are respectively connected to the VDD pin and the GND pin of the microcontroller chip.

[0006] Furthermore, the first LED and the second LED are LEDs of the same color.

[0007] Furthermore, the operating voltage of the first LED bead and the second LED bead connected in series is greater than the operating voltage of the microcontroller chip.

[0008] The beneficial effects of this utility model are as follows: This utility model has a simple structure, requiring only one IO pin and one current-limiting resistor to control two LED beads to achieve four states, which greatly reduces the size and saves hardware costs. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the I / O pins of the first existing microcontroller chip controlling LED beads.

[0010] Figure 2 This is a schematic diagram of the I / O pins of an existing second type of microcontroller chip controlling LED beads.

[0011] Figure 3 This is a schematic diagram of the I / O pins of an existing third type of microcontroller chip controlling LED beads.

[0012] Figure 4 This is a circuit diagram of the battery pack LED display circuit according to an embodiment of the present invention.

[0013] Figure 5 This is a circuit diagram of state 1 of this utility model embodiment.

[0014] Figure 6 This is a circuit diagram of state 2 of this utility model embodiment.

[0015] Figure 7 This is a circuit diagram of state 3 of this utility model embodiment.

[0016] Figure 8 This is a circuit diagram of state 4 of this utility model embodiment. Detailed Implementation

[0017] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] In this embodiment of the invention, directional indicators (such as up, down, left, right, front, back, etc.) are only used to explain the relative positional relationship and movement of the components in a specific posture (as shown in the attached figure). If the specific posture changes, the directional indicators will also change accordingly.

[0019] Furthermore, in this utility model, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0020] Please refer to Figure 4 The battery pack LED display circuit of this utility model embodiment includes a microcontroller chip, a current limiting resistor (i.e., R1), a first LED bead (i.e., LED1), and a second LED bead (i.e., LED2).

[0021] One of the I / O pins of the microcontroller chip is connected to the negative terminal of the first LED and the positive terminal of the second LED via a current-limiting resistor. The positive terminal of the first LED and the negative terminal of the second LED are connected to the VDD and GND pins of the microcontroller chip, respectively. The microcontroller chip controls the on / off state of the two LEDs by controlling the input / output state and high / low level of this I / O pin.

[0022] In one implementation, the first LED bead and the second LED bead are LEDs of the same color.

[0023] In one implementation, the operating voltage of the first LED bead and the second LED bead connected in series is greater than the operating voltage of the microcontroller chip.

[0024] This invention uses a single I / O pin of a microcontroller chip to control two LED beads, achieving the following states: all LEDs are off, all LEDs are on, LED1 is on and LED2 is off, and vice versa. The schematic diagram is shown below. Figure 4 As shown.

[0025] Condition: The forward voltage of LED1 connected in series with LED2 must be greater than the operating voltage of the microcontroller chip. Different colored LEDs have different voltage drops. For example, a red LED operates between 1.8V and 2.2V, so 1.8V * 2 = 3.6V, while the current operating voltage of the microcontroller chip is 3.3V. A green LED operates between 2.8V and 3.6V, so 2.8V * 2 = 5.6V, while the operating voltage of the microcontroller chip is either 3.3V or 5V.

[0026] The working principle of this utility model:

[0027] State 1: Total Annihilation (e.g.) Figure 5 As shown in the diagram, taking a red LED as an example, the chip's IO pin is set as an input pin, U(led1) + U(led2) = 3.6V, while the supply voltage is 3.3V. Since the supply voltage of the LED is not reached, the LED does not light up.

[0028] State 2: Fully lit (e.g.) Figure 6 (As shown), taking a red LED as an example. The chip's I / O pin is set as an output pin. The I / O port outputs a square wave with a period T <= 20ms and a duty cycle of 50%. When the I / O port outputs a low level, LED1 lights up and LED2 turns off. When the I / O port outputs a high level, LED2 lights up and LED1 turns off. LED1 and LED2 alternately light up and turn off, with a cycle of less than 20ms.

[0029] State 3: LED1 is on, LED2 is off (e.g.) Figure 7As shown in the diagram, taking a red LED as an example. Setting the chip's I / O pin low to output and high to input, the I / O port outputs a square wave with a period T <= 20ms and a duty cycle of 50%. When the I / O port outputs a low level, LED1 lights up and LED2 turns off. When the I / O port inputs, LED2 turns off, with a cycle of less than 20ms.

[0030] State 4: LED2 is on, LED1 is off (e.g.) Figure 8 (As shown), taking a red LED as an example. Setting the chip's I / O pin high as an output and low as an input, the I / O port outputs a square wave with a period T <= 20ms and a duty cycle of 50%. When the I / O port outputs a high level, LED2 lights up and LED1 turns off. When the I / O port inputs, LED1 turns off, and the on / off period is less than 20ms.

[0031] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A battery pack LED display circuit, comprising a microcontroller chip, characterized in that, It also includes a current-limiting resistor, a first LED, and a second LED. One of the I / O pins of the microcontroller chip is connected to the negative terminal of the first LED and the positive terminal of the second LED through the current-limiting resistor. The positive terminal of the first LED and the negative terminal of the second LED are respectively connected to the VDD and GND pins of the microcontroller chip.

2. The battery pack LED display circuit as described in claim 1, characterized in that, The first and second LED beads are of the same color.

3. The battery pack LED display circuit as described in claim 1, characterized in that, The operating voltage of the first LED bead and the second LED bead connected in series is greater than the operating voltage of the microcontroller chip.

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