I did small research to study the density of the distribution of the output ADC codes with short-circuited input circuits, and so there is a spread of up to 1000 1_5V and nifiga is not a normal distribution law, which suggests that either there is trouble with the layout of the board, or with the ADC, or all together. To be honest, it has enough noise at all coefficients. do not believe the Chinese documentation" This is confirmed by the user Nikopol_86 in the blog ". If you look at the graph of the input data, then the Gaussian distribution does not even "smell" here. No data filtering methods, by applying all kinds of digital filters, could IN ANY way "tame" the input fluctuations. Illustrative examples of such data capture are shown in the pictures. The given data is taken from the running controller, stopped at the moment of transition to the data indication procedure. From which it can be seen that the most effective, in this case, is a moving average with a window of 16 samples. In the Excel file "Data Acquisition", on the "Moving Average" tab, the result of filtering fluctuating input data InputBuff (swing 436 units) with an averaging window of 3,12,16 intervals is shown. Removing the values was obtained by using the JATAG USB debugger in the AVR Studio environment. I have taken the ADC values at zero effort on the platform and tabulated. When the program is running, the data on the display change their value in a fairly wide range. The choice of this filter is based on the following. The main program starts by creating an input array, CreatInput, and then filters the input data using a moving average method. The variables are basically all global, especially since the mega resources allowed. Keys, a simple program for responding to button presses. The first subroutine: ReadCount, reads data from the ADC module and forms them into the Count variable.ĬreatInput, generates an input transformation data array of 32 values.ĬreatOutput, generates an ADC conversion output data array by organizing a moving average, with a window size of 16 data.
Consists of 4 subroutines and the fifth main main. Although, as they say, "depending on where to apply." unchanged, can be used for some kind of applied needs. The program is oriented towards VERIFICATION, and hardly directly, i.e. Now the program itself, which I use, to work with the module. I hope all the information necessary to repeat my experiments is complete. This allows you to quickly process the results obtained using ready-made methods. It is also important to work with the EXCEL office program.
" This GOST defines the properties of weighing instruments. It is the MECHANICAL properties of the sensor body: the geometric dimensions, the location of the glued strain gauge films, especially the "bone" cut in the middle of the sensor body, the size of the platform that affects the torque applied to the sensor body determine this very independence. Thus, Single Point strain gauges, when using the size specified in the TU platform for the location of the weighed load, are designed so that the unbalance signal of the strain bridge does not depend on the position of the load on the platform. It should be noted that the use of "native" insertion nodes allows obtaining all the postulated output data from the Single Point strain gauge, model CZL A6.
#Codevisionavr 1.25 code#
As a development environment, the Code Vision AVR program, version 1.25.9 professional, AVR Studio 4, Version 4.09.0.338, the AVR JTAG USB programmer was used, which allows not only programming the crystal, but also tracking step by step, if necessary, the execution of the program in the microcontroller, almost in real time.Īs a signal source for the ADC, a strain gauge, made in China, with a maximum weighing limit of 40 kg was chosen. To test this module, a circuit was assembled based on an ATmega16 microcontroller, an ADC module, a two-line LCD BC1602, based on an HD44780 controller, four buttons. Notes on the operation of this module are also on this site in Andrey Gerasimenko's blog "ADC НХ711 from 3.3V - do not believe the Chinese documentation and not only.
The converter itself is assembled as a ready-made module according to the connection scheme recommended by the manufacturer (?).
The reason for writing this post is to understand the Hx711 24-bit delta-sigma ADC converter module.
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