Low-cost vehicle-mounted interface key detection circuit

Abstract

The utility model discloses a low-cost vehicle-mounted interface key detection circuit, which belongs to the technical field of vehicle-mounted domain controller interface detection and comprises a first diode D1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a first key K1, a second key K2, a third key K3, a fourth key K4 and a fifth key K5. The second end of the first diode D1 is connected with the first end of the first resistor R1, and the first ends of the second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6 are connected with the second end of the first resistor R1 and the first end of the seventh resistor R7. The first end of the first key K1, the first end of the second key K2, the first end of the third key K3, the first end of the fourth key K4 and the first end of the fifth key K5 are connected with the second end of the second resistor R2, the second end of the third resistor R3, the second end of the fourth resistor R4, the second end of the fifth resistor R5 and the second end of the sixth resistor R6, and different functions of the keys are achieved by inputting different AD voltage values to an I / O control port of the MCU.

Description

TECHNICAL FIELD

[0001] The utility model relates to vehicle-mounted field controller interface detection technical field, concretely is a low -cost vehicle-mounted interface button detection circuit. BACKGROUND

[0002] With the progress of science and technology, the automobile electronic system is more and more perfect, and the function is more and more, as the important component of automobile electronic system, the function of vehicle-mounted audio entertainment equipment is also more and more, and the cost is also increased. In our company in chery project, according to customer demand and product features, to meet the button demand of multiple functions, save cost, therefore, a low -cost vehicle-mounted interface button detection circuit is proposed.

[0003] The effect that needs to be reached: one I / O controls 5 kinds of function needs;

[0004] The voltage range that needs to be met is as follows:

[0005] SWC_DET (1): 0V - 0.4V;

[0006] SWC_DET (2): 0.6V - 1.0V;

[0007] SWC_DET (3): 1.3V - 1.7V;

[0008] SWC_DET (4): 2.0V - 2.4V;

[0009] SWC_DET (5): 2.6V - 3.0V.

[0010] Therefore, a low -cost vehicle-mounted interface button detection circuit is proposed. UTILITY MODEL CONTENT

[0011] The utility model aims at providing a low -cost vehicle-mounted interface button detection circuit to solve the problem in the background art.

[0012] To achieve the above object, the utility model provides the following technical scheme: a low -cost vehicle-mounted interface button detection circuit, comprising: first diode D1, first resistance R1, second resistance R2, third resistance R3, fourth resistance R4, fifth resistance R5, sixth resistance R6, seventh resistance R7, first button K1, second button K2, third button K3, fourth button K4, fifth button K5;

[0013] The 2 end of first diode D1 is connected with the 1 end of first resistance R1;

[0014] The 1 end of the second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5, the sixth resistor R6 is connected with the 2 end of the first resistor R1 and the 1 end of the seventh resistor R7.

[0015] The 1 end of the first key K1, the second key K2, the third key K3, the fourth key K4, the fifth key K5 is connected with the 2 end of the second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5, the sixth resistor R6.

[0016] Preferably, the 2 end of the first key K1, the second key K2, the third key K3, the fourth key K4, the fifth key K5 is grounded.

[0017] Preferably, the 1 end of the first diode D1 is connected to a +3.3V power supply.

[0018] Preferably, the 2 end of the seventh resistor R7 is connected to an AD voltage value output network SWC_DET.

[0019] Compared with the prior art, the beneficial effects of the utility model are that: by using low-cost resistor voltage dividing circuit, different AD voltage values input to the I / O control port of MCU, different functions of the keys are realized, the system design requirements are met, and the optimal solution of design cost is found. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is the circuit schematic diagram of the utility model. DETAILED DESCRIPTION

[0021] The technical schemes in the embodiments of the utility model will be clearly and completely described below in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model.

[0022] Please refer to Figure 1 The utility model provides a kind of technical scheme: a kind of low-cost vehicle-mounted interface key detection circuit, comprising: first diode D1, first resistor R1, second resistor R2, third resistor R3, fourth resistor R4, fifth resistor R5, sixth resistor R6, seventh resistor R7, first key K1, second key K2, third key K3, fourth key K4, fifth key K5;

[0023] The 2 end of the first diode D1 is connected with the 1 end of the first resistor R1;

[0024] The 1 end of the second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6 is connected with the 2 end of the first resistor R1 and the 1 end of the seventh resistor R7.

[0025] The 1 end of the first key K1, the second key K2, the third key K3, the fourth key K4, and the fifth key K5 is connected with the 2 end of the second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6.

[0026] Reference example: the 2 end of the first key K1, the second key K2, the third key K3, the fourth key K4, and the fifth key K5 is grounded.

[0027] Reference example: the 1 end of the first diode D1 is connected to the +3.3V power supply.

[0028] Reference example: the 2 end of the seventh resistor R7 is connected to the AD voltage value output network SWC_DET.

[0029] Test example:

[0030] When the key K1 / K2 / K3 / K4 / K5 is not in action, the SWC_DET output voltage is 3.15V;

[0031] When the key K1 is pressed, the AD voltage value (VSWC_DET) detected by the SWC_DET is 0V;

[0032] The circuit parameter calculation formula is as follows:

[0033] VSWC_DET = (V3V3_SW - VD1)* (R2) / (R1+R2) ①

[0034] Substitute the parameters to obtain:

[0035] VSWC_DET = (3.3 - 0.15)* (0) / (0+1.5) = 0V ②

[0036] When the key K2 is pressed, the AD voltage value detected by the SWC_DET is 0.75V;

[0037] The circuit parameter calculation formula is as follows:

[0038] VSWC_DET = (V3V3_SW - VD1)* (R3) / (R1+R3) ①

[0039] Substitute the parameters to obtain:

[0040] VSWC_DET = (3.3 - 0.15)* (0.47) / (0.47+1.5) = 0.75V ②

[0041] In this way, when the key K3 is pressed, the AD voltage value detected by SWC_DET is 1.52V; when K4 is pressed, the AD voltage value detected by SWC_DET is 2.22V; when K5 is pressed, the AD voltage value detected by SWC_DET is 2.74V. The above voltages are respectively within the five detection voltage ranges, which meet the design requirements.

[0042] By increasing the resistance adjustment value of the voltage division resistor, different output voltage values can be set, and more functional requirements can be achieved.

[0043] Although the embodiments of the utility model have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirits of the utility model, and the scope of the utility model is defined by the appended claims and their equivalents.

Claims

1. A low cost on-board interface key detection circuit, characterized in that, Include: The first diode (D1), the first resistance (R1), the second resistance (R2), the third resistance (R3), the fourth resistance (R4), the fifth resistance (R5), the sixth resistance (R6), the seventh resistance (R7), the first button (K1), the second button (K2), the third button (K3), the fourth button (K4), the fifth button (K5); The 2 end of the first diode (D1) is connected with the 1 end of the first resistance (R1); The 1 end of the second resistance (R2), the third resistance (R3), the fourth resistance (R4), the fifth resistance (R5), the sixth resistance (R6) is connected with the 2 end of the first resistance (R1), the 1 end of the seventh resistance (R7); The 1 end of the first button (K1), the second button (K2), the third button (K3), the fourth button (K4), the fifth button (K5) is connected with the 2 end of the second resistance (R2), the third resistance (R3), the fourth resistance (R4), the fifth resistance (R5), the sixth resistance (R6).

2. The low cost on-board interface key detection circuit according to claim 1, characterized in that: The 2 end of the first button (K1), the second button (K2), the third button (K3), the fourth button (K4), the fifth button (K5) is grounded.

3. The low cost on-board interface key detection circuit of claim 1, wherein: The 1 end of the first diode (D1) is connected to +3.3V power supply.

4. The low cost on-board interface key detection circuit of claim 1, wherein: The 2 end of the seventh resistance (R7) is connected to AD voltage value output network SWC_DET.

Images