LED Frequency Display Module PLJ-6LED-A User Manual V 1.1
Three Swords Studio Dan Rongsheng March 2013 Guangxi Nanning Longan
table of Contents
Overview ................................................. ........................................... 1 technical parameters .... .................................................. ...................................... 2 How it works ......... .................................................. ................................. 3 Design Ideas .............. .................................................. .......................... 5 Using the Operation ................... .................................................. ....................... 7 Test samples ........................ .................................................. ................ 10 Using the Questions ............................... .................................................. ......... 11 About DIY ...................................... .................................................. 12
Overview
PLJ-6LED-A is designed for the forum HAM Friends of the cost-effective design of the six LED frequency display module, mainly for the transceiver and other equipment, the value of the frequency display can also be used for conventional frequency measurement. This module has small and exquisite, reliable performance, visual effects, low cost and so on.
main feature:
Ø Microchip's PIC16F628A as the core of the 65MHz frequency meter. Ø Frequency reference voltage compensated crystal oscillator (± 2.5 ppm VC-TCXO). Ø Unique gate control method and precise time algorithm. Ø gate (display refresh) time 0.1 seconds, real-time display frequency value. Ø Frequency measurement accuracy 10Hz / 100Hz (right one) optional. Ø Dual IF design, IF value and add / subtract mode can be individually preset, do not affect each other. Ø LED display driver with a dedicated chip, digital tube high brightness, external interference less. Ø using six 0.56-inch digital tube display, null null automatically blanking, eight brightness adjustable. Ø The circuit is simple, reasonable structure, double key control, simple operation. Ø The settings are automatically saved, boot directly call.
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Measuring range: 0.1 MHz ~ 65 MHz Accuracy: 10 Hz Sensitivity: better than 60mVPP
3. IF set independent dual IF design, adjust the minimum step frequency of 100 Hz, IF range of 0 ~ 99.9999 MHz, can be set to increase the IF or reduced IF mode.
4. Frequency reference is 5032 package 13.000MHz Warm-up Voltage-controlled Crystal Oscillator (VC-TCXO) with frequency stability of ± 2.5 ppm.
5. Operating voltage DC input: DC 8V ~ 15V (reverse polarity protection with a power supply) or DC 5V (need to set the hardware).
6. Maximum operating current of 90 mA
7. Display Digits Six common anode LED display, the highest six figures.
8. Display brightness Eight-level LED brightness adjustable, the factory set to the highest brightness.
9. Physical size L × W × H: 91 mm × 28 mm × 20 mm
10. Onboard interface RF IN (signal input): ICSP (programming interface): DC IN (power interface):
HX2.54-2P socket 2.54-6P pin HX2.54-2P socket
© 2008 Sanjian Studio Three Swords Studio
E-mail: drsh1@163.com
QQ: 307693659
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PLJ-6LED-A
1. Gate time 0.1 seconds
2. Measuring channel input impedance: high impedance
Technical Parameters
Preamplifier
working principle
RF signal from the RF IN into the front-end broadband amplification.
Signal amplification by the input impedance of the dual-gate FET BF998R, C3356 and its peripheral components, 50K trimmer resistor to adjust the C3356 operating point to change the channel sensitivity, amplified signal into the MCU's RA4 to count, within the Schmitt trigger RA4 The device acts as a signal shaping.
PLJ-6LED-A
5V
RF IN
B1
L1 10UH
C5 C6 C7
C8
103 R5
10K
Q1 BF998R
R3 330
W1 50K
C11 104
C9 104
10UF
D2 IN4148
104 104
IN4148
R4 470
F_OUT
Q2 C3356 (R25)
1 2
D3
C14 104
0.1MHz to 65MHz
Preamplifier
MCU control
R1 10K
5V
IC2 PIC16F628A
8DIO 7 CLK
1 18 17
MCLR
13 PGD 12 PGC
4
MCLR RB7 RB6 RB5
RB4
RB3 RA3 RB2 RB1 RA4 / T0CKI RB0
RA2 OSC1 / CLKIN RA1 OSC2 / CLKOUT RA0
11 10 9
F_OUT
TCXO
R22 470
16 15
6
3
MCU control
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5 VSS VDD 14
PLJ-6LED-A
PIC16F628A the RB1, RB2 TM1637 are the clock and data control side. RA6 and RA7 as the online programming interface ICSP, but also double-IF switching and the last bit of the display blanking control side. RA4 counts external pulses, and RA3 controls gate.
Display and key control
5V
DIO CLK
B g
DS1 LED-5631BH
DS2 LED-5631BH
R8 R9 10K 10K
C17 C18 100 100
IC3 TM1637
19 20
2aa
12
Aa bb cc dd ee ff gg dp dp
Display circuit
17
SEG1 / KS1
SEG2 / KS2 DIO SEG3 / KS3 SEG4 / KS4 CLK SEG5 / KS5 SEG6 / KS6 SEG7 / KS7 SEG8 / KS8
GRID1
K1 GRID2 GRID3 GRID4
K2 GRID5 GRID6
A fb
Ec dp
A fb
Ec dp
A fb
Ec dp
A fb
Ec dp
A f
E
A f
E
G
D
G
D
G
D
G
D
3bb
4cc
B g
B g
18
5dd
6ee
7ff
C d
C d
8gg
9 dpdp
Dp
Dp
15 14
13
11
10
SET UP
Button control
TM1637 is a kind of LED drive control circuit with keyboard scanning interface. It integrates MCU digital interface, data latch, LED high voltage driver and keyboard scan circuit. Support for six were Yang digital control, 16 enhanced key scan, 8 brightness adjustment, two-wire serial interface and so on.
This module uses the TM1637 in addition to its circuit is simple, good electrical performance, that is, its price is not cheap, TB price 0.80-1.00 RMB, support domestic chip.
Select the digital display is a forum from a post http://www.hellocq.net/forum/read.php?tid=308847 discussion, LED display with eye-catching, low-cost advantages, but the drawback is obvious , That is, relatively large power consumption.
As for the election six-bit display is a trade-off between resolution and frequency band after the program. When the measurement accuracy is 10Hz, 7.050MHz display 7.050.00, 29.600MHz display 9.600.00 (highest position "2" does not display); measurement accuracy of 100Hz, 7.050MHz display 7.050.0 ("7" before the zero blanking ), 29.600 MHz shows 29.600.0. When the measurement accuracy is 10Hz, the last digit (ie, 10 Hz bit) has jitter, which affects the visual effect. If such a high precision is not necessary, the display content can be shifted to the right by one bit.
Select the 0.56-inch digital tube is the size is moderate, and the layout of the circuit board components just the right size.
The choice of the color and brightness of the digital tube depends on your preference. The samples provided by our studio are mainly bright red and bright yellow-green, with a small amount of highlighted pure green, highlighted blue, highlighted white and highlighted Yellow and other varieties to choose from, but the special color LED costs slightly higher. The brightness of the module at the factory is set to the highest (eight), bright LED display more dazzling, personal feeling bright LED four brightness is more appropriate, please adjust.
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PLJ-6LED-A
Design ideas
L The reference frequency reference is based on a 13000MHz temperature-compensated voltage-controlled crystal oscillator (VC-TCXO), widely used in mobile phones.
The calibration is ± 2.5 ppm.
Because of this frequency for large-scale production, so the cost is very low, Taobao price of 3 yuan for diyer provides a cheap frequency reference.
Using TCXO to make the performance of this module to a higher level.
L the gate signal to be measured by the R2 into the PIC16F628A the RA4 feet to count, the gate time to the PIC16F628A the RA3 pin
From the high-impedance state into the output to prevent changes in the level of RA4 feet, T0 stop external count, this gate control without special gate chip, simple and reliable, easy to transplant to other single-chip, this is one of the frequency meter design highlights .
L For the 89S51 microcontroller for the count, when the timer is running in the counting function, the maximum count frequency value does not exceed
1/24 of the clock frequency FOSC, i.e. the frequency counter of frequency counter completed by T0 or T1 is less than FOSC / 24. Therefore, in order to achieve more than 51 single-chip high-frequency counting function, you have to use external expansion frequency circuit (such as 74LS393, 74AC4040, etc.) to complete, this will make the system's circuit becomes complicated.
PIC microcontroller internal TMR0 has a prescaler, without the need to expand the external circuit, you can easily achieve the following 65MHz frequency count. But there is a problem, that is, PIC microcontroller internal prescaler is not directly read and write, when the gate time, how to know the prescaler in the count value? Ideas are as follows: When the gate time, PIC16F628A the RA3 pin
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PLJ-6LED-A
From the input state into the output state, RA4 pin to stop the external pulse count, while the RA3 pin generates analog pulse signal to PIC16F628A T0 to count and record the number of pulses RA3 output N, when T0 overflow calculation 255-N, 255 - N is the gate time to the prescaler in the count, no external counter simple design is the frequency meter of the two bright spots.
L on the clock with the microcontroller to do the frequency meter Many designers use timer overflow interrupt to the timing, interrupt latency can still be passed
Rewrite the initial value of the timer to compensate, but the interrupt response time of the microcontroller is sometimes not determined, which determines the interrupt when the microcontroller is executing what kind of instruction, such as MCS-51 microcontroller interrupt system interrupt response time of 3 to 8 Machine cycle, compensation is quite troublesome.
A friend of the design is not concerned about the accuracy of the frequency reference, that can be used to adjust the software, in fact, this is not rigorous practice, will have "cumulative error" or "linear accuracy" of the pulse count type frequency meter design, The accuracy of the frequency reference is important. Of course, we should pay attention to the stability of the frequency reference, there is no guarantee of stability, accuracy is also a cloud.
The frequency meter does not use Timer overflow interrupt method, but the use of software delay method to precise timing. Timer overflow detection is added to the software delay. It is found that the overflow software counter is incremented by 1, the Timer overflow flag is cleared, and then the delay program continues until the end of the delay time. The most critical areas are: The time for overflow detection is also included in the delay time. 2 The timing for inserting the Timer overflow detection is appropriate, that is, every Timer overflow can not be missed. The use of software delay method to ensure the accuracy of timing is the frequency meter design highlights of the three.
L About the IF This machine has two intermediate frequency, convenient to use dual IF machine, display frequency = signal frequency ± intermediate frequency value. In the reduced-IF
Mode, if the signal frequency is less than the set IF value, the frequency value is displayed as zero. SET button to set the IF value and add / subtract mode, the two IF switching ICSP programming interface by the first four feet to select the level to achieve.
L programming environment: MPLAB IDE V8.88 Compilation Tools: HI-TECH PICC V9.60 programming tools: PICkit 3 code written in C language, gate timing part of the embedded assembly, occupying 2045 words (99.9%) program space.
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PLJ-6LED-A
1. The machine structure
Use the operation
Power supply interface SET button
PCB front (3D view) Frequency fine-tuning programming interface
Sensitivity adjustment signal input
▲ key
Second, the installation size
PCB back (3D view)
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E-mail: drsh1@163.com
QQ: 307693659
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PLJ-6LED-A
Third, the operation steps (A) preparatory work
1. Please check the power supply voltage (DC 8V-15V) and polarity before using, and then check the power supply. The machine power supply circuit in series with a diode, the power polarity anti-machine does not work, but will not produce destructive consequences.
2. Measurement signal input 2P square mouth seat access test line (wired) or antenna (sensing mode). (B) feature set
System Settings
Red: Displays characters
Blue: flashing characters Press the SET button to press the SET button
Normal working condition
IF value setting
DISPLAY Press the SET button and press the SET key. 0 0.0 0 0.0 0 0.0 0 0.0
0 0.0 0 0.0 Press the ▲ key
0 0.0 0 0.1 Press the ▲ key
0 0.0 0 0.2 Press the ▲ key
0 0.0 0 0.9
display
Press the ▲ key
1 0.0 0 0.0 Press the ▲ key
2 0.0 0 0.0 Press the ▲ key
9 0.0 0 0.0 plus the intermediate frequency
Press the ▲ key
0 1.0 0 0.0 Press the ▲ key
0 2.0 0 0.0 Press the ▲ key
0 9.0 0 0.0 Decreasing the intermediate frequency
∩IF Press ▲ key ∪IF Press SET key Press SET key
Exit the IF value setting
Addition and subtraction IF switching
LED brightness setting
Quit the midrange switch
Press the SET button
display
01 Press ▲ key 02 Press ▲ button 03 Press ▲ button 08 Press SET button Press SET button Press SET button Press SET button
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Quit the LED brightness setting
Press the ▲ key
Press the ▲ key
Press the ▲ key
Press the SET button
Press the SET button
PLJ-6LED-A
Display adjustment (one bit to the right)
7.050.00
10Hz precision
Press ▲ key to press ▲ key
7.050.0
100Hz precision
4.270.00
10Hz precision
Press ▲ key to press ▲ key
14.270.0
100Hz precision
System reset
Off state
Press and hold the SET button to release the SET key firmware version
IF switch
Turn on the power
Xx.xx.xx
Reset is complete
The two IF switching ICSP programming interface by the level of the first four feet to achieve the first 4 feet high or vacant when using the first IF, the first four feet low when the use of the second IF. Two intermediate frequency is independent, intermediate frequency value and addition and subtraction mode can be preset separately, do not interfere with each other. 4 feet high or vacant when the first intermediate frequency can be preset, the first four feet can be set to a low level of the second intermediate frequency. Factory default pin 4 set to use the first floating middle IF, IF value is zero, plus / minus mode is reduced. In practice, the programming interface ICSP 4 feet and 3 feet (GND) with a 2P DuPont line leads (below red circle position), the use of switches or microcontroller control programming interface ICSP pin 4 level to achieve two IF and transceiver synchronous switching.
(3) Measure the frequency Use the test line to connect the RF IN (signal input) port with the transceiver local oscillator output or other test points.
The frequency value of the test point can be displayed in real time. The high-impedance input design of this module helps to reduce the impact on the local oscillator circuit. The local oscillator output signal of the transceiver should have a certain intensity (greater than 60mVPP). The oscillations such as NE602 / NE612 are weak and may not be able to read stable frequency value.
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testing sample
To facilitate the use of testing, the Sanjian studio from time to time to provide small quantities of samples, those who need to enter the main page Taobao search "Three Swords Studio" or "PLJ-6LED-A" keywords can also be directly with the studio .
PLJ-6LED-A
Sample Description:
N Patch device mounting n Reflow process n Using six 0.56-inch LEDs n Including mounting studs n No power supply, no housing n Commissioned
packing list:
N PLJ-6LED-A module 1 piece n XH2.54-2P20cm single head wire 2 pieces n anti-static bag packing 1 pcs
Precautions:
N kit distribution of the two XH2.54-2P 20cm single-headed line, do not use color as the basis for judging the polarity, according to the polarity of the module socket to determine the polarity, the details of the use of this manual to read the contents of the operation.
N Do not place the instrument in a hot, humid, dusty environment and prevent severe vibration. N The factory-set clock reference has been calibrated with a rubidium atomic clock, and the sensitivity is adjusted to the optimum level. It is not necessary to adjust the clock. N Under normal use of the warranty period of six months. Warranty does not apply due to improper use, modification and other non-normal conditions lead to damage
Bad product.
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Use Q & A
Road, carefully check the voltage and polarity and then turn on the power, otherwise it will have serious consequences.
1. For the convenience of installation, can use the transceiver 5V power supply for the module? Yes, you need to do the hardware settings, the red circle in the picture below the two pads shorted, you can directly from the DC IN Connect to 5V
The DC power supply powers the module. This change should be careful, because then the external power supply bypasses the module of the regulator and polarity anti-reverse power
PLJ-6LED-A
2. Does this module interfere with the transceiver?
Said there is no interference is not possible, microcontroller, crystal, LED driver will have a certain external radiation, but the intensity will not be too much in the design has taken certain measures, in addition, the module and transceiver sensitive devices The distance, the characteristics of the transceiver have a certain relationship. If there is interference, try to change the installation location of the module or add shielding.
3. Frequency value shows what is the reason for instability?
First of all, to ensure that the input signal quality (strength, stability, etc.) to achieve the minimum requirements of the module (see parameters), and signal input line to use shielded cable, the third should pay attention to ensure the quality of power, ripple Not too much.
4.When there is no measured signal, why does it show irregular beating?
First check the power supply for this module ripple is too large, and then check the other around the module is strong signal radiation. This module has invalid signal filter function, less than 100KHz signal will be filtered, the normal display should be zero.
5. Can the upper limit of the measurement frequency be increased? Please pay attention to the PLJ-8LED-A developed by Sanjian Studio. The working upper limit can reach 1000 MHz, and the time gate has many choices.
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PLJ-6LED-A
About DIY
Forum announced the manufacturing PLJ-6LED-A full set of information, we can directly send the Gerber file to the PCB factory processing.
Programming has been programmed in the programming bit, most of the programmer has a function to read the programming bit, without human intervention. If you can not identify the writer, crystal type HS election, the remaining options can be closed.
Summary of the previous version of the various conditions, the Forum published in the burning of documents added to the use of the number of restrictions, the first 25 times, it will display "------" limit to continue to use, then reset the system SET key to boot) to resume use, in addition, hardware and software without other technical trap.
Attached: Previously published in hellocq.net frequency meter information 2008-11-03: http: //www.hellocq.net/forum/read.php? Tid = 189583
2008-11-04: http: //www.hellocq.net/forum/read.php? Tid = 189696 2008-11-05: http: //www.hellocq.net/forum/read.php? Tid = 189718 2009-03-30: http: //www.hellocq.net/forum/read.php? Tid = 200868 2011-04-27: http: //www.hellocq.net/forum/read.php? Tid = 264417 2011-12-14: http: //www.hellocq.net/forum/read.php? Tid = 282626 2013-03-22: http: //www.hellocq.net/forum/read.php? Tid = 312288
The intellectual property of this product is owned by Sanjian Studio. The information published on the network can be copied and reproduced at will, and personal imitation testing is encouraged, but it is forbidden for commercial use.
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