HX711

odemmo · Joined: 26 Jun 2007 Posts: 19

Does anyone have a code to read data from HX711, I just need to read the weight from the load cell and write them to serial, I have searched a lot on the internet without finding anything, please.

(BASCOM-AVR version : 2.0.8.2 )

albertsm · Joined: 09 Apr 2004 Posts: 5915 Location: Holland

the data sheet is reasonable clear.
you can use SHIFTIN or a simple BASIC for next.
The number of pulses selects which channel, and the gain.
I have no code but it looks simple to me from a quick peek in the datasheet.

O-Family · Joined: 23 May 2010 Posts: 320 Location: Japan

Hi,
I tested it and wrote an article.
It should be helpful.

Japanese site.
http://www.ne.jp/asahi/shared/o-family/ElecRoom/AVRMCOM/HX711Test/HX711Test.html

English translation site.
http://translate.google.com/translate?hl=ja&sl=ja&tl=en&u=http%3A%2F%2Fwww.ne.jp%2Fasahi%2Fshared%2Fo-family%2FElecRoom%2FAVRMCOM%2FHX711Test%2FHX711Test.html
http://www.translatetheweb.com/?from=&to=en&ref=TVert&refd=www.bing.com&dl=ja&rr=DC&a=http%3a%2f%2fwww.ne.jp%2fasahi%2fshared%2fo-family%2fElecRoom%2fAVRMCOM%2fHX711Test%2fHX711Test.html

odemmo · Joined: 26 Jun 2007 Posts: 19

albertsm · Joined: 09 Apr 2004 Posts: 5915 Location: Holland

well done O-Family !

odemmo · Joined: 26 Jun 2007 Posts: 19

so far this work for me

$regfile = "m16def.dat"

$crystal = 3686400

$baud = 9600

$hwstack = 64
$swstack = 10
$framesize = 24

Hx711_clk Alias Portd.2
Hx711_dat Alias Pind.3

Dim Hx711ad As Long
Dim Hx711avg As Long
Dim Hx711count As Byte
Dim Average(16) As Long
Dim Avgpoi As Byte
Dim Avgsum As Long
Dim Zeroadj As Long
Dim Stablecount As Byte
Dim Lastvalue As Long
Dim Sensorcal As Long
'
Dim Temp1 As Byte
Dim Temp2 As Byte
Dim Templ1 As Long
Dim Tempstr As String * 40
'
Dim Dummy As Eram Long
Dim Eepprgid As Eram Long
Dim Eepsensorcal As Eram Long

Config Hx711_clk = Output
Reset Hx711_clk
Config Hx711_dat = Input

If Eepprgid <> &H31375848 Then
Eepprgid = &H31375848
Eepsensorcal = 30065
End If
Sensorcal = Eepsensorcal

For Temp1 = 1 To 20
Do

Loop Until Hx711_dat = 0
'
Gosub Hx711get
Gosub Hx711movavg
Locate 2 , 1
Print Hex(hx711avg)
Next Temp1

Zeroadj = 0 - Hx711avg
Stablecount = 0
Lastvalue = 0

Temp2 = 0

Main:
If Hx711_dat = 0 Then
Gosub Hx711get
Gosub Hx711movavg
Templ1 = Hx711avg + Zeroadj

Templ1 = Templ1 * 100
Templ1 = Templ1 / Sensorcal
'
Temp2 = Temp2 + 1
If Temp2 > 10 Then
Temp2 = 0
End If

waitms 100
Tempstr = Str(templ1)
If Templ1 < 0 Then
print Format(tempstr , " 0")
If Temp2 = 0 Then
Print Format(tempstr , " 0")
End If
Else
print Format(tempstr , " 0")
If Temp2 = 0 Then
Print Format(tempstr , " 0")
End If
End If

If Templ1 = Lastvalue Then
Stablecount = Stablecount + 1
If Stablecount > 5 Then
Stablecount = 5

End If
Else
Lastvalue = Templ1
Stablecount = 0

End If
End If
Goto Main

Hx711get:
Hx711ad = 0
For Hx711count = 23 To 0 Step -1
Set Hx711_clk
Waitus 1
Hx711ad.hx711count = Hx711_dat
Reset Hx711_clk
Waitus 1
Next Hx711count

Set Hx711_clk
Waitus 1
Reset Hx711_clk
Waitus 1
'
If Hx711ad.23 = 1 Then
Hx711ad = Hx711ad Or &HFF000000
End If
Return

Hx711movavg:
Avgsum = Avgsum - Average(avgpoi)
Average(avgpoi) = Hx711ad
Avgsum = Avgsum + Hx711ad
'
Avgpoi = Avgpoi + 1
If Avgpoi > 16 Then
Avgpoi = 1
End If
'
Hx711avg = Avgsum
Shift Hx711avg , Right , 4 , Signed
Return

eid

O-Family · Joined: 23 May 2010 Posts: 320 Location: Japan

I'm glad I could help you!

Calibration and zero adjustment are required depending on the type of load cell, so please devise it.

odemmo · Joined: 26 Jun 2007 Posts: 19

odemmo · Joined: 26 Jun 2007 Posts: 19

Next, how can I read data from 4 pcs. hx711 with 1 Atmega 8?

O-Family · Joined: 23 May 2010 Posts: 320 Location: Japan

All you have to do is assign [PD_SCK] and [DOUT] for 4 circuits to different ports and execute a program to extract A/D data for each port.

EDC · Joined: 26 Mar 2014 Posts: 971

Hello. Im also using HX711 in some of my projects but I cant wait for the measure (SERIALS/DOS,ETH/temperatures etc.). So I handle it similarly like DS18B20.

I cut this code from one of bigger projects.
Because HX711 is temperature sensitive then one TARE is not enough. I add simple Autotare that walk thru chip is gettin warm from rest of electronic.
Maybe this can be handy for someone.

albertsm · Joined: 09 Apr 2004 Posts: 5915 Location: Holland

thanks for sharing. indeed good practice to calibrate.

odemmo · Joined: 26 Jun 2007 Posts: 19

O-Family · Joined: 23 May 2010 Posts: 320 Location: Japan

You can create four types of ports for the program you copied and worked on, and call each of them.

Duval JP · Joined: 22 Jun 2004 Posts: 1162 Location: France

hi, I have added a HX711 on my clock see https://www.mcselec.com/index2.php?option=com_forum&Itemid=59&page=viewtopic&t=14726
JP Wink